Fixes ViewVariablesManager using the wrong VVPropEditor for Type in shared not annotated with [NetSerializable]

Someone please performance-test this, but I think the fragment shader code simplifications speak for themselves.

Radrark found the "line in polar coordinates" equation I needed and a diagram that explained the variables.

That equation was essentially the missing piece to the whole thing.

.github/workflows/codeql-analysis.yml

@@ -11,14 +11,14 @@
 #
 name: "CodeQL"
 
-on:
-  push:
-    branches: [ master ]
-  pull_request:
-    # The branches below must be a subset of the branches above
-    branches: [ master ]
-  schedule:
-    - cron: '30 18 * * 6'
+#on:
+#  push:
+#    branches: [ master ]
+#  pull_request:
+#    # The branches below must be a subset of the branches above
+#    branches: [ master ]
+#  schedule:
+#    - cron: '30 18 * * 6'
 
 jobs:
   analyze:
@@ -38,12 +38,12 @@ jobs:
       uses: actions/checkout@v2
       with:
         submodules: true
-        
+
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v1
       with:
         dotnet-version: 5.0.100
-        
+
     - name: Build
       run: dotnet build
 

.gitmodules

@@ -4,6 +4,12 @@
 [submodule "Lidgren.Network"]
 	path = Lidgren.Network/Lidgren.Network
 	url = https://github.com/space-wizards/lidgren-network-gen3.git
+[submodule "XamlX"]
+	path = XamlX
+	url = https://github.com/space-wizards/XamlX
 [submodule "Robust.LoaderApi"]
 	path = Robust.LoaderApi
 	url = https://github.com/space-wizards/Robust.LoaderApi.git
+[submodule "ManagedHttpListener"]
+	path = ManagedHttpListener
+	url = https://github.com/space-wizards/ManagedHttpListener.git

MSBuild/XamlIL.targets

@@ -0,0 +1,63 @@
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="12.0">
+  <PropertyGroup>
+    <RobustUseExternalMSBuild>true</RobustUseExternalMSBuild>
+    <_RobustUseExternalMSBuild>$(RobustUseExternalMSBuild)</_RobustUseExternalMSBuild>
+    <_RobustUseExternalMSBuild Condition="'$(_RobustForceInternalMSBuild)' == 'true'">false</_RobustUseExternalMSBuild>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Update="**\*.xaml.cs">
+      <DependentUpon>%(Filename)</DependentUpon>
+    </Compile>
+    <EmbeddedResource Include="**\*.xaml"/>
+    <AdditionalFiles Include="**\*.xaml"/>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="$(MSBuildThisFileDirectory)\..\Robust.Client.NameGenerator\Robust.Client.NameGenerator.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false"/>
+    <ProjectReference Include="$(MSBuildThisFileDirectory)\..\Robust.Client.Injectors\Robust.Client.Injectors.csproj" ReferenceOutputAssembly="false"/>
+  </ItemGroup>
+
+  <UsingTask
+    Condition="'$(_RobustUseExternalMSBuild)' != 'true' And $(DesignTimeBuild) != true"
+    TaskName="CompileRobustXamlTask"
+    AssemblyFile="$(MSBuildThisFileDirectory)\..\Robust.Client.Injectors\bin\$(Configuration)\netstandard2.0\Robust.Client.Injectors.dll"/>
+  <Target
+    Name="CompileRobustXaml"
+    Condition="Exists('@(IntermediateAssembly)')"
+    AfterTargets="AfterCompile"
+    Inputs="@(IntermediateAssembly);@(ReferencePathWithRefAssemblies)"
+    Outputs="$(IntermediateOutputPath)XAML/doot">
+    <PropertyGroup>
+      <RobustXamlReferencesTemporaryFilePath Condition="'$(RobustXamlReferencesTemporaryFilePath)' == ''">$(IntermediateOutputPath)XAML/references</RobustXamlReferencesTemporaryFilePath>
+      <RobustXamlOriginalCopyFilePath Condition="'$(RobustXamlOriginalCopyFilePath)' == ''">$(IntermediateOutputPath)XAML/original.dll</RobustXamlOriginalCopyFilePath>
+    </PropertyGroup>
+    <WriteLinesToFile
+      Condition="'$(_RobustForceInternalMSBuild)' != 'true'"
+      File="$(RobustXamlReferencesTemporaryFilePath)"
+      Lines="@(ReferencePathWithRefAssemblies)"
+      Overwrite="true"/>
+
+    <!--
+    UpdateBuildIndicator is done so that we can use MSBuild Inputs and Outputs on the target
+    to avoid unecessary execution of this target
+    Saves compile time if e.g. ONLY Robust.Client changes (Content.Client doesn't have to re-xaml).
+    -->
+    <CompileRobustXamlTask
+      Condition="'$(_RobustUseExternalMSBuild)' != 'true'"
+      AssemblyFile="@(IntermediateAssembly)"
+      ReferencesFilePath="$(RobustXamlReferencesTemporaryFilePath)"
+      OriginalCopyPath="$(RobustXamlOriginalCopyFilePath)"
+      ProjectDirectory="$(MSBuildProjectDirectory)"
+      AssemblyOriginatorKeyFile="$(AssemblyOriginatorKeyFile)"
+      SignAssembly="$(SignAssembly)"
+      DelaySign="$(DelaySign)"
+      UpdateBuildIndicator="$(IntermediateOutputPath)XAML/doot"/>
+
+    <PropertyGroup>
+      <DOTNET_HOST_PATH Condition="'$(DOTNET_HOST_PATH)' == ''">dotnet</DOTNET_HOST_PATH>
+    </PropertyGroup>
+    <Exec
+      Condition="'$(_RobustUseExternalMSBuild)' == 'true'"
+      Command="&quot;$(DOTNET_HOST_PATH)&quot; msbuild /nodereuse:false $(MSBuildProjectFile) /t:CompileRobustXaml /p:_RobustForceInternalMSBuild=true /p:Configuration=$(Configuration) /p:RuntimeIdentifier=$(RuntimeIdentifier) /p:TargetFramework=$(TargetFramework) /p:BuildProjectReferences=false"/>
+  </Target>
+</Project>

OpenToolkit.GraphicsLibraryFramework/GLFWNative.cs

@@ -17,6 +17,7 @@ namespace OpenToolkit.GraphicsLibraryFramework
             // On net472, we rely on Mono's DllMap for this. See the .dll.config file.
             NativeLibrary.SetDllImportResolver(typeof(GLFWNative).Assembly, (name, assembly, path) =>
             {
+                // Please keep in sync with what Robust.Shared/DllMapHelper.cs does.
                 if (name != "glfw3.dll")
                 {
                     return IntPtr.Zero;

Resources/Shaders/Internal/light-soft.swsl

@@ -13,7 +13,7 @@ highp float createOcclusion(highp vec2 diff)
     // Change soft shadow size based on distance from primary occluder.
     highp float distRatio = (ourDist - occlDist.x) / occlDist.x / 2.0;
 
-    perpendicular *= distRatio;
+    perpendicular *= distRatio * lightSoftness;
 
     // Totally not hacky PCF on top of VSM.
     highp float occlusion = smoothstep(0.1, 1.0, ChebyshevUpperBound(occlDist, ourDist));

Resources/Shaders/Internal/light_shared.swsl

@@ -13,6 +13,7 @@ uniform highp vec4 lightColor;
 uniform highp vec2 lightCenter;
 uniform highp float lightRange;
 uniform highp float lightPower;
+uniform highp float lightSoftness;
 uniform highp float lightIndex;
 uniform sampler2D shadowMap;
 

Robust.Client.Injectors/CompileRobustXamlTask.cs

@@ -0,0 +1,101 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using Microsoft.Build.Framework;
+
+namespace Robust.Build.Tasks
+{
+    /// <summary>
+    /// Based on https://github.com/AvaloniaUI/Avalonia/blob/c85fa2b9977d251a31886c2534613b4730fbaeaf/src/Avalonia.Build.Tasks/CompileAvaloniaXamlTask.cs
+    /// </summary>
+    public class CompileRobustXamlTask : ITask
+    {
+        public bool Execute()
+        {
+            //Debugger.Launch();
+            OutputPath = OutputPath ?? AssemblyFile;
+            var outputPdb = GetPdbPath(OutputPath);
+            var input = AssemblyFile;
+            var inputPdb = GetPdbPath(input);
+            // Make a copy and delete the original file to prevent MSBuild from thinking that everything is OK
+            if (OriginalCopyPath != null)
+            {
+                File.Copy(AssemblyFile, OriginalCopyPath, true);
+                input = OriginalCopyPath;
+                File.Delete(AssemblyFile);
+
+                if (File.Exists(inputPdb))
+                {
+                    var copyPdb = GetPdbPath(OriginalCopyPath);
+                    File.Copy(inputPdb, copyPdb, true);
+                    File.Delete(inputPdb);
+                    inputPdb = copyPdb;
+                }
+            }
+
+            var msg = $"CompileRobustXamlTask -> AssemblyFile:{AssemblyFile}, ProjectDirectory:{ProjectDirectory}, OutputPath:{OutputPath}";
+            BuildEngine.LogMessage(msg, MessageImportance.High);
+
+            var res = XamlCompiler.Compile(BuildEngine, input,
+                File.ReadAllLines(ReferencesFilePath).Where(l => !string.IsNullOrWhiteSpace(l)).ToArray(),
+                ProjectDirectory, OutputPath,
+                (SignAssembly && !DelaySign) ? AssemblyOriginatorKeyFile : null);
+            if (!res.success)
+                return false;
+            if (!res.writtentofile)
+            {
+                File.Copy(input, OutputPath, true);
+                if(File.Exists(inputPdb))
+                    File.Copy(inputPdb, outputPdb, true);
+            }
+
+            if (!string.IsNullOrEmpty(UpdateBuildIndicator))
+            {
+                if (!File.Exists(UpdateBuildIndicator))
+                {
+                    File.Create(UpdateBuildIndicator).Dispose();
+                }
+                else
+                {
+                    File.SetLastWriteTime(UpdateBuildIndicator, DateTime.Now);
+                }
+            }
+
+            return true;
+        }
+
+        [Required]
+        public string ReferencesFilePath { get; set; }
+
+        [Required]
+        public string ProjectDirectory { get; set; }
+
+        [Required]
+        public string AssemblyFile { get; set; }
+
+        [Required]
+        public string OriginalCopyPath { get; set; }
+
+        public string OutputPath { get; set; }
+        public string UpdateBuildIndicator { get; set; }
+
+        public string AssemblyOriginatorKeyFile { get; set; }
+        public bool SignAssembly { get; set; }
+        public bool DelaySign { get; set; }
+
+        // shamelessly copied from avalonia
+        string GetPdbPath(string p)
+        {
+            var d = Path.GetDirectoryName(p);
+            var f = Path.GetFileNameWithoutExtension(p);
+            var rv = f + ".pdb";
+            if (d != null)
+                rv = Path.Combine(d, rv);
+            return rv;
+        }
+
+        public IBuildEngine BuildEngine { get; set; }
+        public ITaskHost HostObject { get; set; }
+    }
+}

Robust.Client.Injectors/Extensions.cs

@@ -0,0 +1,16 @@
+using Microsoft.Build.Framework;
+
+namespace Robust.Build.Tasks
+{
+    /// <summary>
+    /// Taken from https://github.com/AvaloniaUI/Avalonia/blob/c85fa2b9977d251a31886c2534613b4730fbaeaf/src/Avalonia.Build.Tasks/Extensions.cs
+    /// </summary>
+    public static class Extensions
+    {
+        //shamefully copied from avalonia
+        public static void LogMessage(this IBuildEngine engine, string message, MessageImportance imp)
+        {
+            engine.LogMessageEvent(new BuildMessageEventArgs(message, "", "Avalonia", imp));
+        }
+    }
+}

Robust.Client.Injectors/Program.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Collections;
+using System.IO;
+using Microsoft.Build.Framework;
+
+namespace Robust.Build.Tasks
+{
+    /// <summary>
+    /// Based on https://github.com/AvaloniaUI/Avalonia/blob/c85fa2b9977d251a31886c2534613b4730fbaeaf/src/Avalonia.Build.Tasks/Program.cs
+    /// </summary>
+    class Program
+    {
+        static int Main(string[] args)
+        {
+            if (args.Length != 3)
+            {
+                Console.Error.WriteLine("expected: input references output");
+                return 1;
+            }
+
+            return new CompileRobustXamlTask
+            {
+                AssemblyFile = args[0],
+                ReferencesFilePath = args[1],
+                OutputPath = args[2],
+                BuildEngine = new ConsoleBuildEngine(),
+                ProjectDirectory = Directory.GetCurrentDirectory()
+            }.Execute() ? 0 : 2;
+        }
+    }
+
+    class ConsoleBuildEngine : IBuildEngine
+    {
+        public void LogErrorEvent(BuildErrorEventArgs e)
+        {
+            Console.WriteLine($"ERROR: {e.Code} {e.Message} in {e.File} {e.LineNumber}:{e.ColumnNumber}-{e.EndLineNumber}:{e.EndColumnNumber}");
+        }
+
+        public void LogWarningEvent(BuildWarningEventArgs e)
+        {
+            Console.WriteLine($"WARNING: {e.Code} {e.Message} in {e.File} {e.LineNumber}:{e.ColumnNumber}-{e.EndLineNumber}:{e.EndColumnNumber}");
+        }
+
+        public void LogMessageEvent(BuildMessageEventArgs e)
+        {
+            Console.WriteLine($"MESSAGE: {e.Code} {e.Message} in {e.File} {e.LineNumber}:{e.ColumnNumber}-{e.EndLineNumber}:{e.EndColumnNumber}");
+        }
+
+        public void LogCustomEvent(CustomBuildEventArgs e)
+        {
+            Console.WriteLine($"CUSTOM: {e.Message}");
+        }
+
+        public bool BuildProjectFile(string projectFileName, string[] targetNames, IDictionary globalProperties,
+            IDictionary targetOutputs) => throw new NotSupportedException();
+
+        public bool ContinueOnError { get; }
+        public int LineNumberOfTaskNode { get; }
+        public int ColumnNumberOfTaskNode { get; }
+        public string ProjectFileOfTaskNode { get; }
+    }
+}

Robust.Client.Injectors/Robust.Client.Injectors.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netstandard2.0</TargetFramework>
+        <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <PackageReference Include="Microsoft.Build.Framework" Version="16.8.0" />
+      <PackageReference Include="Mono.Cecil" Version="0.11.3" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\XamlX\src\XamlX.IL.Cecil\XamlX.IL.Cecil.csproj" />
+    </ItemGroup>
+</Project>

Robust.Client.Injectors/RobustXamlILCompiler.cs

@@ -0,0 +1,201 @@
+using System.Linq;
+using XamlX.Ast;
+using XamlX.Emit;
+using XamlX.IL;
+using XamlX.Transform;
+using XamlX.TypeSystem;
+
+namespace Robust.Build.Tasks
+{
+    /// <summary>
+    /// Emitters & Transformers based on:
+    /// - https://github.com/AvaloniaUI/Avalonia/blob/c85fa2b9977d251a31886c2534613b4730fbaeaf/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlRootObjectScopeTransformer.cs
+    /// - https://github.com/AvaloniaUI/Avalonia/blob/c85fa2b9977d251a31886c2534613b4730fbaeaf/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AddNameScopeRegistration.cs
+    /// </summary>
+    public class RobustXamlILCompiler : XamlILCompiler
+    {
+        public RobustXamlILCompiler(TransformerConfiguration configuration, XamlLanguageEmitMappings<IXamlILEmitter, XamlILNodeEmitResult> emitMappings, bool fillWithDefaults) : base(configuration, emitMappings, fillWithDefaults)
+        {
+            Transformers.Add(new AddNameScopeRegistration());
+            Transformers.Add(new RobustMarkRootObjectScopeNode());
+
+            Emitters.Add(new AddNameScopeRegistration.Emitter());
+            Emitters.Add(new RobustMarkRootObjectScopeNode.Emitter());
+        }
+
+        class AddNameScopeRegistration : IXamlAstTransformer
+        {
+            public IXamlAstNode Transform(AstTransformationContext context, IXamlAstNode node)
+            {
+                if (node is XamlPropertyAssignmentNode pa)
+                {
+                    if (pa.Property.Name == "Name"
+                        && pa.Property.DeclaringType.FullName == "Robust.Client.UserInterface.Control")
+                    {
+                        if (context.ParentNodes().FirstOrDefault() is XamlManipulationGroupNode mg
+                            && mg.Children.OfType<RobustNameScopeRegistrationXamlIlNode>().Any())
+                            return node;
+
+                        IXamlAstValueNode value = null;
+                        for (var c = 0; c < pa.Values.Count; c++)
+                            if (pa.Values[c].Type.GetClrType().Equals(context.Configuration.WellKnownTypes.String))
+                            {
+                                value = pa.Values[c];
+                                if (!(value is XamlAstTextNode))
+                                {
+                                    var local = new XamlAstCompilerLocalNode(value);
+                                    // Wrap original in local initialization
+                                    pa.Values[c] = new XamlAstLocalInitializationNodeEmitter(value, value, local);
+                                    // Use local
+                                    value = local;
+                                }
+
+                                break;
+                            }
+
+                        if (value != null)
+                        {
+                            var objectType = context.ParentNodes().OfType<XamlAstConstructableObjectNode>().FirstOrDefault()?.Type.GetClrType();
+                            return new XamlManipulationGroupNode(pa)
+                            {
+                                Children =
+                                {
+                                    pa,
+                                    new RobustNameScopeRegistrationXamlIlNode(value, objectType)
+                                }
+                            };
+                        }
+                    }
+                    /*else if (pa.Property.CustomAttributes.Select(attr => attr.Type).Intersect(context.Configuration.TypeMappings.DeferredContentPropertyAttributes).Any())
+                    {
+                        pa.Values[pa.Values.Count - 1] =
+                            new NestedScopeMetadataNode(pa.Values[pa.Values.Count - 1]);
+                    }*/
+                }
+
+                return node;
+            }
+
+            class RobustNameScopeRegistrationXamlIlNode : XamlAstNode, IXamlAstManipulationNode
+            {
+                public IXamlAstValueNode Name { get; set; }
+                public IXamlType TargetType { get; }
+
+                public RobustNameScopeRegistrationXamlIlNode(IXamlAstValueNode name, IXamlType targetType) : base(name)
+                {
+                    TargetType = targetType;
+                    Name = name;
+                }
+
+                public override void VisitChildren(IXamlAstVisitor visitor)
+                    => Name = (IXamlAstValueNode)Name.Visit(visitor);
+            }
+
+            internal class Emitter : IXamlAstLocalsNodeEmitter<IXamlILEmitter, XamlILNodeEmitResult>
+            {
+                public XamlILNodeEmitResult Emit(IXamlAstNode node, XamlEmitContextWithLocals<IXamlILEmitter, XamlILNodeEmitResult> context, IXamlILEmitter codeGen)
+                {
+                    if (node is RobustNameScopeRegistrationXamlIlNode registration)
+                    {
+
+                        var scopeField = context.RuntimeContext.ContextType.Fields.First(f =>
+                            f.Name == XamlCompiler.ContextNameScopeFieldName);
+                        var namescopeRegisterFunction = context.Configuration.TypeSystem
+                            .FindType("Robust.Client.UserInterface.XAML.NameScope").Methods
+                            .First(m => m.Name == "Register");
+
+                        using (var targetLoc = context.GetLocalOfType(context.Configuration.TypeSystem.FindType("Robust.Client.UserInterface.Control")))
+                        {
+
+                            codeGen
+                                // var target = {pop}
+                                .Stloc(targetLoc.Local)
+                                // _context.NameScope.Register(Name, target)
+                                .Ldloc(context.ContextLocal)
+                                .Ldfld(scopeField);
+
+                            context.Emit(registration.Name, codeGen, registration.Name.Type.GetClrType());
+
+                            codeGen
+                                .Ldloc(targetLoc.Local)
+                                .EmitCall(namescopeRegisterFunction, true);
+                        }
+
+                        return XamlILNodeEmitResult.Void(1);
+                    }
+                    return default;
+                }
+            }
+        }
+
+        class RobustMarkRootObjectScopeNode : IXamlAstTransformer
+        {
+            public IXamlAstNode Transform(AstTransformationContext context, IXamlAstNode node)
+            {
+                if (!context.ParentNodes().Any()
+                    && node is XamlValueWithManipulationNode mnode)
+                {
+                    mnode.Manipulation = new XamlManipulationGroupNode(mnode,
+                        new[]
+                        {
+                            mnode.Manipulation,
+                            new HandleRootObjectScopeNode(mnode)
+                        });
+                }
+                return node;
+            }
+            class HandleRootObjectScopeNode : XamlAstNode, IXamlAstManipulationNode
+            {
+                public HandleRootObjectScopeNode(IXamlLineInfo lineInfo) : base(lineInfo)
+                {
+                }
+            }
+            internal class Emitter : IXamlILAstNodeEmitter
+            {
+                public XamlILNodeEmitResult Emit(IXamlAstNode node, XamlEmitContext<IXamlILEmitter, XamlILNodeEmitResult> context, IXamlILEmitter codeGen)
+                {
+                    if (!(node is HandleRootObjectScopeNode))
+                    {
+                        return null;
+                    }
+
+                    var controlType = context.Configuration.TypeSystem.FindType("Robust.Client.UserInterface.Control");
+
+                    var next = codeGen.DefineLabel();
+                    var dontAbsorb = codeGen.DefineLabel();
+                    var end = codeGen.DefineLabel();
+                    var contextScopeField = context.RuntimeContext.ContextType.Fields.First(f =>
+                        f.Name == XamlCompiler.ContextNameScopeFieldName);
+                    var controlNameScopeField = controlType.Fields.First(f => f.Name == "NameScope");
+                    var nameScopeType = context.Configuration.TypeSystem
+                        .FindType("Robust.Client.UserInterface.XAML.NameScope");
+                    var nameScopeCompleteMethod = nameScopeType.Methods.First(m => m.Name == "Complete");
+                    var nameScopeAbsorbMethod = nameScopeType.Methods.First(m => m.Name == "Absorb");
+                    using (var local = codeGen.LocalsPool.GetLocal(controlType))
+                    {
+                        codeGen
+                            .Isinst(controlType)
+                            .Dup()
+                            .Stloc(local.Local) //store control in local field
+                            .Brfalse(next) //if control is null, move to next (this should never happen but whatev, avalonia does it)
+                            .Ldloc(context.ContextLocal)
+                            .Ldfld(contextScopeField)
+                            .Ldloc(local.Local) //load control from local field
+                            .Ldfld(controlNameScopeField) //load namescope field from control
+                            .EmitCall(nameScopeAbsorbMethod, true)
+                            .Ldloc(local.Local) //load control
+                            .Ldloc(context.ContextLocal) //load contextObject
+                            .Ldfld(contextScopeField) //load namescope field from context obj
+                            .Stfld(controlNameScopeField) //store namescope field in control
+                            .MarkLabel(next)
+                            .Ldloc(context.ContextLocal)
+                            .Ldfld(contextScopeField)
+                            .EmitCall(nameScopeCompleteMethod, true); //set the namescope as complete
+                    }
+
+                    return XamlILNodeEmitResult.Void(1);
+                }
+            }
+        }
+    }
+}

Robust.Client.Injectors/XamlCompiler.Helpers.cs

@@ -0,0 +1,78 @@
+using System.Collections.Generic;
+using System.Linq;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+using Mono.Collections.Generic;
+using XamlX.TypeSystem;
+
+namespace Robust.Build.Tasks
+{
+    /// <summary>
+    /// Helpers taken from:
+    /// - https://github.com/AvaloniaUI/Avalonia/blob/c85fa2b9977d251a31886c2534613b4730fbaeaf/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs
+    /// - https://github.com/AvaloniaUI/Avalonia/blob/c85fa2b9977d251a31886c2534613b4730fbaeaf/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.Helpers.cs
+    /// </summary>
+    public partial class XamlCompiler
+    {
+        static bool CheckXamlName(IResource r) => r.Name.ToLowerInvariant().EndsWith(".xaml")
+                                                  || r.Name.ToLowerInvariant().EndsWith(".paml")
+                                                  || r.Name.ToLowerInvariant().EndsWith(".axaml");
+
+        private static bool MatchThisCall(Collection<Instruction> instructions, int idx)
+        {
+            var i = instructions[idx];
+            // A "normal" way of passing `this` to a static method:
+
+            // ldarg.0
+            // call void [Avalonia.Markup.Xaml]Avalonia.Markup.Xaml.AvaloniaXamlLoader::Load(object)
+
+            return i.OpCode == OpCodes.Ldarg_0 || (i.OpCode == OpCodes.Ldarg && i.Operand?.Equals(0) == true);
+        }
+
+        interface IResource : IFileSource
+        {
+            string Uri { get; }
+            string Name { get; }
+            void Remove();
+
+        }
+
+        interface IResourceGroup
+        {
+            string Name { get; }
+            IEnumerable<IResource> Resources { get; }
+        }
+
+        class EmbeddedResources : IResourceGroup
+        {
+            private readonly AssemblyDefinition _asm;
+            public string Name => "EmbeddedResource";
+
+            public IEnumerable<IResource> Resources => _asm.MainModule.Resources.OfType<EmbeddedResource>()
+                .Select(r => new WrappedResource(_asm, r)).ToList();
+
+            public EmbeddedResources(AssemblyDefinition asm)
+            {
+                _asm = asm;
+            }
+            class WrappedResource : IResource
+            {
+                private readonly AssemblyDefinition _asm;
+                private readonly EmbeddedResource _res;
+
+                public WrappedResource(AssemblyDefinition asm, EmbeddedResource res)
+                {
+                    _asm = asm;
+                    _res = res;
+                }
+
+                public string Uri => $"resm:{Name}?assembly={_asm.Name.Name}";
+                public string Name => _res.Name;
+                public string FilePath => Name;
+                public byte[] FileContents => _res.GetResourceData();
+
+                public void Remove() => _asm.MainModule.Resources.Remove(_res);
+            }
+        }
+    }
+}

Robust.Client.Injectors/XamlCompiler.cs

@@ -0,0 +1,327 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using Microsoft.Build.Framework;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+using Mono.Cecil.Rocks;
+using XamlX;
+using XamlX.Ast;
+using XamlX.Emit;
+using XamlX.IL;
+using XamlX.Parsers;
+using XamlX.Transform;
+using XamlX.TypeSystem;
+
+namespace Robust.Build.Tasks
+{
+    /// <summary>
+    /// Based on https://github.com/AvaloniaUI/Avalonia/blob/c85fa2b9977d251a31886c2534613b4730fbaeaf/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs
+    /// Adjusted for our UI-Framework
+    /// </summary>
+    public partial class XamlCompiler
+    {
+        public static (bool success, bool writtentofile) Compile(IBuildEngine engine, string input, string[] references,
+            string projectDirectory, string output, string strongNameKey)
+        {
+            var typeSystem = new CecilTypeSystem(references
+                .Where(r => !r.ToLowerInvariant().EndsWith("robust.build.tasks.dll"))
+                .Concat(new[] { input }), input);
+
+            var asm = typeSystem.TargetAssemblyDefinition;
+
+            if (asm.MainModule.GetType("CompiledRobustXaml", "XamlIlContext") != null)
+            {
+                // If this type exists, the assembly has already been processed by us.
+                // Do not run again, it would corrupt the file.
+                // This *shouldn't* be possible due to Inputs/Outputs dependencies in the build system,
+                // but better safe than sorry eh?
+                engine.LogWarningEvent(new BuildWarningEventArgs("XAMLIL", "", "", 0, 0, 0, 0, "Ran twice on same assembly file; ignoring.", "", ""));
+                return (true, false);
+            }
+
+            var compileRes = CompileCore(engine, typeSystem);
+            if (compileRes == null)
+                return (true, false);
+            if (compileRes == false)
+                return (false, false);
+
+            var writerParameters = new WriterParameters { WriteSymbols = asm.MainModule.HasSymbols };
+            if (!string.IsNullOrWhiteSpace(strongNameKey))
+                writerParameters.StrongNameKeyBlob = File.ReadAllBytes(strongNameKey);
+
+            asm.Write(output, writerParameters);
+
+            return (true, true);
+
+        }
+
+        static bool? CompileCore(IBuildEngine engine, CecilTypeSystem typeSystem)
+        {
+            var asm = typeSystem.TargetAssemblyDefinition;
+            var embrsc = new EmbeddedResources(asm);
+
+            if (embrsc.Resources.Count(CheckXamlName) == 0)
+                // Nothing to do
+                return null;
+
+            var xamlLanguage = new XamlLanguageTypeMappings(typeSystem)
+            {
+                XmlnsAttributes =
+                {
+                    typeSystem.GetType("Robust.Client.UserInterface.XAML.XmlnsDefinitionAttribute"),
+
+                },
+                ContentAttributes =
+                {
+                    typeSystem.GetType("Robust.Client.UserInterface.XAML.ContentAttribute")
+                },
+                UsableDuringInitializationAttributes =
+                {
+                    typeSystem.GetType("Robust.Client.UserInterface.XAML.UsableDuringInitializationAttribute")
+                },
+                DeferredContentPropertyAttributes =
+                {
+                    typeSystem.GetType("Robust.Client.UserInterface.XAML.DeferredContentAttribute")
+                },
+                RootObjectProvider = typeSystem.GetType("Robust.Client.UserInterface.XAML.ITestRootObjectProvider"),
+                UriContextProvider = typeSystem.GetType("Robust.Client.UserInterface.XAML.ITestUriContext"),
+                ProvideValueTarget = typeSystem.GetType("Robust.Client.UserInterface.XAML.ITestProvideValueTarget"),
+            };
+            var emitConfig = new XamlLanguageEmitMappings<IXamlILEmitter, XamlILNodeEmitResult>
+            {
+                ContextTypeBuilderCallback = (b,c) => EmitNameScopeField(xamlLanguage, typeSystem, b, c)
+            };
+
+            var transformerconfig = new TransformerConfiguration(
+                typeSystem,
+                typeSystem.TargetAssembly,
+                xamlLanguage,
+                XamlXmlnsMappings.Resolve(typeSystem, xamlLanguage));
+
+            var contextDef = new TypeDefinition("CompiledRobustXaml", "XamlIlContext",
+                TypeAttributes.Class, asm.MainModule.TypeSystem.Object);
+            asm.MainModule.Types.Add(contextDef);
+            var contextClass = XamlILContextDefinition.GenerateContextClass(typeSystem.CreateTypeBuilder(contextDef), typeSystem,
+                xamlLanguage, emitConfig);
+
+            var compiler =
+                new RobustXamlILCompiler(transformerconfig, emitConfig, true);
+
+            var loaderDispatcherDef = new TypeDefinition("CompiledRobustXaml", "!XamlLoader",
+                TypeAttributes.Class, asm.MainModule.TypeSystem.Object);
+
+            var loaderDispatcherMethod = new MethodDefinition("TryLoad",
+                MethodAttributes.Static | MethodAttributes.Public,
+                asm.MainModule.TypeSystem.Object)
+            {
+                Parameters = {new ParameterDefinition(asm.MainModule.TypeSystem.String)}
+            };
+            loaderDispatcherDef.Methods.Add(loaderDispatcherMethod);
+            asm.MainModule.Types.Add(loaderDispatcherDef);
+
+            var stringEquals = asm.MainModule.ImportReference(asm.MainModule.TypeSystem.String.Resolve().Methods.First(
+                m =>
+                    m.IsStatic && m.Name == "Equals" && m.Parameters.Count == 2 &&
+                    m.ReturnType.FullName == "System.Boolean"
+                    && m.Parameters[0].ParameterType.FullName == "System.String"
+                    && m.Parameters[1].ParameterType.FullName == "System.String"));
+
+            bool CompileGroup(IResourceGroup group)
+            {
+                var typeDef = new TypeDefinition("CompiledRobustXaml", "!" + group.Name, TypeAttributes.Class,
+                    asm.MainModule.TypeSystem.Object);
+
+                //typeDef.CustomAttributes.Add(new CustomAttribute(ed));
+                asm.MainModule.Types.Add(typeDef);
+                var builder = typeSystem.CreateTypeBuilder(typeDef);
+
+                foreach (var res in group.Resources.Where(CheckXamlName))
+                {
+                    try
+                    {
+                        engine.LogMessage($"XAMLIL: {res.Name} -> {res.Uri}", MessageImportance.Low);
+
+                        var xaml = new StreamReader(new MemoryStream(res.FileContents)).ReadToEnd();
+                        var parsed = XDocumentXamlParser.Parse(xaml);
+
+                        var initialRoot = (XamlAstObjectNode) parsed.Root;
+
+                        var classDirective = initialRoot.Children.OfType<XamlAstXmlDirective>()
+                            .FirstOrDefault(d => d.Namespace == XamlNamespaces.Xaml2006 && d.Name == "Class");
+                        string classname;
+                        if (classDirective != null && classDirective.Values[0] is XamlAstTextNode tn)
+                        {
+                            classname = tn.Text;
+                        }
+                        else
+                        {
+                            classname = res.Name.Replace(".xaml","");
+                        }
+
+                        var classType = typeSystem.TargetAssembly.FindType(classname);
+                        if (classType == null)
+                            throw new Exception($"Unable to find type '{classname}'");
+
+                        compiler.Transform(parsed);
+
+                        var populateName = $"Populate:{res.Name}";
+                        var buildName = $"Build:{res.Name}";
+
+                        var classTypeDefinition = typeSystem.GetTypeReference(classType).Resolve();
+
+                        var populateBuilder = typeSystem.CreateTypeBuilder(classTypeDefinition);
+
+                        compiler.Compile(parsed, contextClass,
+                            compiler.DefinePopulateMethod(populateBuilder, parsed, populateName,
+                                classTypeDefinition == null),
+                            compiler.DefineBuildMethod(builder, parsed, buildName, true),
+                            null,
+                            (closureName, closureBaseType) =>
+                                populateBuilder.DefineSubType(closureBaseType, closureName, false),
+                            res.Uri, res
+                        );
+
+                        //add compiled populate method
+                        var compiledPopulateMethod = typeSystem.GetTypeReference(populateBuilder).Resolve().Methods
+                            .First(m => m.Name == populateName);
+
+                        const string TrampolineName = "!XamlIlPopulateTrampoline";
+                        var trampoline = new MethodDefinition(TrampolineName,
+                            MethodAttributes.Static | MethodAttributes.Private, asm.MainModule.TypeSystem.Void);
+                        trampoline.Parameters.Add(new ParameterDefinition(classTypeDefinition));
+                        classTypeDefinition.Methods.Add(trampoline);
+
+                        trampoline.Body.Instructions.Add(Instruction.Create(OpCodes.Ldnull));
+                        trampoline.Body.Instructions.Add(Instruction.Create(OpCodes.Ldarg_0));
+                        trampoline.Body.Instructions.Add(Instruction.Create(OpCodes.Call, compiledPopulateMethod));
+                        trampoline.Body.Instructions.Add(Instruction.Create(OpCodes.Ret));
+
+                        var foundXamlLoader = false;
+                        // Find RobustXamlLoader.Load(this) and replace it with !XamlIlPopulateTrampoline(this)
+                        foreach (var method in classTypeDefinition.Methods
+                            .Where(m => !m.Attributes.HasFlag(MethodAttributes.Static)))
+                        {
+                            var i = method.Body.Instructions;
+                            for (var c = 1; c < i.Count; c++)
+                            {
+                                if (i[c].OpCode == OpCodes.Call)
+                                {
+                                    var op = i[c].Operand as MethodReference;
+
+                                    if (op != null
+                                        && op.Name == TrampolineName)
+                                    {
+                                        foundXamlLoader = true;
+                                        break;
+                                    }
+
+                                    if (op != null
+                                        && op.Name == "Load"
+                                        && op.Parameters.Count == 1
+                                        && op.Parameters[0].ParameterType.FullName == "System.Object"
+                                        && op.DeclaringType.FullName == "Robust.Client.UserInterface.XAML.RobustXamlLoader")
+                                    {
+                                        if (MatchThisCall(i, c - 1))
+                                        {
+                                            i[c].Operand = trampoline;
+                                            foundXamlLoader = true;
+                                        }
+                                    }
+                                }
+                            }
+                        }
+
+                        if (!foundXamlLoader)
+                        {
+                            var ctors = classTypeDefinition.GetConstructors()
+                                .Where(c => !c.IsStatic).ToList();
+                            // We can inject xaml loader into default constructor
+                            if (ctors.Count == 1 && ctors[0].Body.Instructions.Count(o=>o.OpCode != OpCodes.Nop) == 3)
+                            {
+                                var i = ctors[0].Body.Instructions;
+                                var retIdx = i.IndexOf(i.Last(x => x.OpCode == OpCodes.Ret));
+                                i.Insert(retIdx, Instruction.Create(OpCodes.Call, trampoline));
+                                i.Insert(retIdx, Instruction.Create(OpCodes.Ldarg_0));
+                            }
+                            else
+                            {
+                                throw new InvalidProgramException(
+                                    $"No call to RobustXamlLoader.Load(this) call found anywhere in the type {classType.FullName} and type seems to have custom constructors.");
+                            }
+                        }
+
+                        //add compiled build method
+                        var compiledBuildMethod = typeSystem.GetTypeReference(builder).Resolve().Methods
+                            .First(m => m.Name == buildName);
+                        var parameterlessCtor = classTypeDefinition.GetConstructors()
+                            .FirstOrDefault(c => c.IsPublic && !c.IsStatic && !c.HasParameters);
+
+                        if (compiledBuildMethod != null && parameterlessCtor != null)
+                        {
+                            var i = loaderDispatcherMethod.Body.Instructions;
+                            var nop = Instruction.Create(OpCodes.Nop);
+                            i.Add(Instruction.Create(OpCodes.Ldarg_0));
+                            i.Add(Instruction.Create(OpCodes.Ldstr, res.Uri));
+                            i.Add(Instruction.Create(OpCodes.Call, stringEquals));
+                            i.Add(Instruction.Create(OpCodes.Brfalse, nop));
+                            if (parameterlessCtor != null)
+                                i.Add(Instruction.Create(OpCodes.Newobj, parameterlessCtor));
+                            else
+                            {
+                                i.Add(Instruction.Create(OpCodes.Call, compiledBuildMethod));
+                            }
+
+                            i.Add(Instruction.Create(OpCodes.Ret));
+                            i.Add(nop);
+                        }
+                    }
+                    catch (Exception e)
+                    {
+                        engine.LogWarningEvent(new BuildWarningEventArgs("XAMLIL", "", res.Uri, 0, 0, 0, 0,
+                            e.ToString(), "", "CompileRobustXaml"));
+                    }
+                }
+                return true;
+            }
+
+            if (embrsc.Resources.Count(CheckXamlName) != 0)
+            {
+                if (!CompileGroup(embrsc))
+                    return false;
+            }
+
+            loaderDispatcherMethod.Body.Instructions.Add(Instruction.Create(OpCodes.Ldnull));
+            loaderDispatcherMethod.Body.Instructions.Add(Instruction.Create(OpCodes.Ret));
+            return true;
+        }
+
+        public const string ContextNameScopeFieldName = "RobustNameScope";
+
+        private static void EmitNameScopeField(XamlLanguageTypeMappings xamlLanguage, CecilTypeSystem typeSystem, IXamlTypeBuilder<IXamlILEmitter> typeBuilder, IXamlILEmitter constructor)
+        {
+            var nameScopeType = typeSystem.FindType("Robust.Client.UserInterface.XAML.NameScope");
+            var field = typeBuilder.DefineField(nameScopeType,
+                ContextNameScopeFieldName, true, false);
+            constructor
+                .Ldarg_0()
+                .Newobj(nameScopeType.GetConstructor())
+                .Stfld(field);
+        }
+    }
+
+    interface IResource : IFileSource
+    {
+        string Uri { get; }
+        string Name { get; }
+        void Remove();
+
+    }
+
+    interface IResourceGroup
+    {
+        string Name { get; }
+        IEnumerable<IResource> Resources { get; }
+    }
+}

Robust.Client.NameGenerator/NameReferenceSyntaxReceiver.cs

@@ -0,0 +1,21 @@
+using System.Collections.Generic;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace Robust.Client.NameGenerator
+{
+    /// <summary>
+    /// Taken from https://github.com/AvaloniaUI/Avalonia.NameGenerator/blob/ecc9677a23de5cbc90af07ccac14e31c0da41d6a/src/Avalonia.NameGenerator/NameReferenceSyntaxReceiver.cs
+    /// </summary>
+    internal class NameReferenceSyntaxReceiver : ISyntaxReceiver
+    {
+        public List<ClassDeclarationSyntax> CandidateClasses { get; } = new List<ClassDeclarationSyntax>();
+
+        public void OnVisitSyntaxNode(SyntaxNode syntaxNode)
+        {
+            if (syntaxNode is ClassDeclarationSyntax classDeclarationSyntax &&
+                classDeclarationSyntax.AttributeLists.Count > 0)
+                CandidateClasses.Add(classDeclarationSyntax);
+        }
+    }
+}

Robust.Client.NameGenerator/Robust.Client.NameGenerator.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netstandard2.0</TargetFramework>
+    </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="3.8.0" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.2" PrivateAssets="all" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Link="XamlX\filename" Include="../XamlX/src/XamlX/**/*.cs" />
+    <Compile Remove="../XamlX/src/XamlX/**/SreTypeSystem.cs" />
+    <Compile Remove="../XamlX/src/XamlX/obj/**" />
+  </ItemGroup>
+</Project>

Robust.Client.NameGenerator/RoslynTypeSystem.cs

@@ -0,0 +1,287 @@
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using XamlX.TypeSystem;
+
+namespace Robust.Client.NameGenerator
+{
+    /// <summary>
+    /// Taken from https://github.com/AvaloniaUI/Avalonia.NameGenerator/blob/ecc9677a23de5cbc90af07ccac14e31c0da41d6a/src/Avalonia.NameGenerator/Infrastructure/RoslynTypeSystem.cs
+    /// </summary>
+     public class RoslynTypeSystem : IXamlTypeSystem
+    {
+        private readonly List<IXamlAssembly> _assemblies = new List<IXamlAssembly>();
+
+        public RoslynTypeSystem(CSharpCompilation compilation)
+        {
+            _assemblies.Add(new RoslynAssembly(compilation.Assembly));
+
+            var assemblySymbols = compilation
+                .References
+                .Select(compilation.GetAssemblyOrModuleSymbol)
+                .OfType<IAssemblySymbol>()
+                .Select(assembly => new RoslynAssembly(assembly))
+                .ToList();
+
+            _assemblies.AddRange(assemblySymbols);
+        }
+
+        public IReadOnlyList<IXamlAssembly> Assemblies => _assemblies;
+
+        public IXamlAssembly FindAssembly(string substring) => _assemblies[0];
+
+        public IXamlType FindType(string name)
+        {
+            foreach (var assembly in _assemblies)
+            {
+                var type = assembly.FindType(name);
+                if (type != null)
+                    return type;
+            }
+
+            return null;
+        }
+
+        public IXamlType FindType(string name, string assembly)
+        {
+            foreach (var assemblyInstance in _assemblies)
+            {
+                var type = assemblyInstance.FindType(name);
+                if (type != null)
+                    return type;
+            }
+
+            return null;
+        }
+    }
+
+    public class RoslynAssembly : IXamlAssembly
+    {
+        private readonly IAssemblySymbol _symbol;
+
+        public RoslynAssembly(IAssemblySymbol symbol) => _symbol = symbol;
+
+        public bool Equals(IXamlAssembly other) =>
+            other is RoslynAssembly roslynAssembly &&
+            SymbolEqualityComparer.Default.Equals(_symbol, roslynAssembly._symbol);
+
+        public string Name => _symbol.Name;
+
+        public IReadOnlyList<IXamlCustomAttribute> CustomAttributes =>
+            _symbol.GetAttributes()
+                .Select(data => new RoslynAttribute(data, this))
+                .ToList();
+
+        public IXamlType FindType(string fullName)
+        {
+            var type = _symbol.GetTypeByMetadataName(fullName);
+            return type is null ? null : new RoslynType(type, this);
+        }
+    }
+
+    public class RoslynAttribute : IXamlCustomAttribute
+    {
+        private readonly AttributeData _data;
+        private readonly RoslynAssembly _assembly;
+
+        public RoslynAttribute(AttributeData data, RoslynAssembly assembly)
+        {
+            _data = data;
+            _assembly = assembly;
+        }
+
+        public bool Equals(IXamlCustomAttribute other) =>
+            other is RoslynAttribute attribute &&
+            _data == attribute._data;
+
+        public IXamlType Type => new RoslynType(_data.AttributeClass, _assembly);
+
+        public List<object> Parameters =>
+            _data.ConstructorArguments
+                .Select(argument => argument.Value)
+                .ToList();
+
+        public Dictionary<string, object> Properties =>
+            _data.NamedArguments.ToDictionary(
+                pair => pair.Key,
+                pair => pair.Value.Value);
+    }
+
+    public class RoslynType : IXamlType
+    {
+        private static readonly SymbolDisplayFormat SymbolDisplayFormat = new SymbolDisplayFormat(
+            typeQualificationStyle: SymbolDisplayTypeQualificationStyle.NameAndContainingTypesAndNamespaces,
+            genericsOptions: SymbolDisplayGenericsOptions.IncludeTypeParameters |
+                             SymbolDisplayGenericsOptions.IncludeTypeConstraints |
+                             SymbolDisplayGenericsOptions.IncludeVariance);
+
+        private readonly RoslynAssembly _assembly;
+        private readonly INamedTypeSymbol _symbol;
+
+        public RoslynType(INamedTypeSymbol symbol, RoslynAssembly assembly)
+        {
+            _symbol = symbol;
+            _assembly = assembly;
+        }
+
+        public bool Equals(IXamlType other) =>
+            other is RoslynType roslynType &&
+            SymbolEqualityComparer.Default.Equals(_symbol, roslynType._symbol);
+
+        public object Id => _symbol;
+
+        public string Name => _symbol.Name;
+
+        public string Namespace => _symbol.ContainingNamespace.ToDisplayString(SymbolDisplayFormat);
+
+        public string FullName => $"{Namespace}.{Name}";
+
+        public IXamlAssembly Assembly => _assembly;
+
+        public IReadOnlyList<IXamlProperty> Properties =>
+            _symbol.GetMembers()
+                .Where(member => member.Kind == SymbolKind.Property)
+                .OfType<IPropertySymbol>()
+                .Select(property => new RoslynProperty(property, _assembly))
+                .ToList();
+
+        public IReadOnlyList<IXamlEventInfo> Events { get; } = new List<IXamlEventInfo>();
+
+        public IReadOnlyList<IXamlField> Fields { get; } = new List<IXamlField>();
+
+        public IReadOnlyList<IXamlMethod> Methods { get; } = new List<IXamlMethod>();
+
+        public IReadOnlyList<IXamlConstructor> Constructors =>
+            _symbol.Constructors
+                .Select(method => new RoslynConstructor(method, _assembly))
+                .ToList();
+
+        public IReadOnlyList<IXamlCustomAttribute> CustomAttributes { get; } = new List<IXamlCustomAttribute>();
+
+        public IReadOnlyList<IXamlType> GenericArguments { get; } = new List<IXamlType>();
+
+        public bool IsAssignableFrom(IXamlType type) => type == this;
+
+        public IXamlType MakeGenericType(IReadOnlyList<IXamlType> typeArguments) => this;
+
+        public IXamlType GenericTypeDefinition => this;
+
+        public bool IsArray => false;
+
+        public IXamlType ArrayElementType { get; } = null;
+
+        public IXamlType MakeArrayType(int dimensions) => null;
+
+        public IXamlType BaseType => _symbol.BaseType == null ? null : new RoslynType(_symbol.BaseType, _assembly);
+
+        public bool IsValueType { get; } = false;
+
+        public bool IsEnum { get; } = false;
+
+        public IReadOnlyList<IXamlType> Interfaces =>
+            _symbol.AllInterfaces
+                .Select(abstraction => new RoslynType(abstraction, _assembly))
+                .ToList();
+
+        public bool IsInterface => _symbol.IsAbstract;
+
+        public IXamlType GetEnumUnderlyingType() => null;
+
+        public IReadOnlyList<IXamlType> GenericParameters { get; } = new List<IXamlType>();
+    }
+
+    public class RoslynConstructor : IXamlConstructor
+    {
+        private readonly IMethodSymbol _symbol;
+        private readonly RoslynAssembly _assembly;
+
+        public RoslynConstructor(IMethodSymbol symbol, RoslynAssembly assembly)
+        {
+            _symbol = symbol;
+            _assembly = assembly;
+        }
+
+        public bool Equals(IXamlConstructor other) =>
+            other is RoslynConstructor roslynConstructor &&
+            SymbolEqualityComparer.Default.Equals(_symbol, roslynConstructor._symbol);
+
+        public bool IsPublic => true;
+
+        public bool IsStatic => false;
+
+        public IReadOnlyList<IXamlType> Parameters =>
+            _symbol.Parameters
+                .Select(parameter => parameter.Type)
+                .OfType<INamedTypeSymbol>()
+                .Select(type => new RoslynType(type, _assembly))
+                .ToList();
+    }
+
+    public class RoslynProperty : IXamlProperty
+    {
+        private readonly IPropertySymbol _symbol;
+        private readonly RoslynAssembly _assembly;
+
+        public RoslynProperty(IPropertySymbol symbol, RoslynAssembly assembly)
+        {
+            _symbol = symbol;
+            _assembly = assembly;
+        }
+
+        public bool Equals(IXamlProperty other) =>
+            other is RoslynProperty roslynProperty &&
+            SymbolEqualityComparer.Default.Equals(_symbol, roslynProperty._symbol);
+
+        public string Name => _symbol.Name;
+
+        public IXamlType PropertyType =>
+            _symbol.Type is INamedTypeSymbol namedTypeSymbol
+                ? new RoslynType(namedTypeSymbol, _assembly)
+                : null;
+
+        public IXamlMethod Getter => _symbol.GetMethod == null ? null : new RoslynMethod(_symbol.GetMethod, _assembly);
+
+        public IXamlMethod Setter => _symbol.SetMethod == null ? null : new RoslynMethod(_symbol.SetMethod, _assembly);
+
+        public IReadOnlyList<IXamlCustomAttribute> CustomAttributes { get; } = new List<IXamlCustomAttribute>();
+
+        public IReadOnlyList<IXamlType> IndexerParameters { get; } = new List<IXamlType>();
+    }
+
+    public class RoslynMethod : IXamlMethod
+    {
+        private readonly IMethodSymbol _symbol;
+        private readonly RoslynAssembly _assembly;
+
+        public RoslynMethod(IMethodSymbol symbol, RoslynAssembly assembly)
+        {
+            _symbol = symbol;
+            _assembly = assembly;
+        }
+
+        public bool Equals(IXamlMethod other) =>
+            other is RoslynMethod roslynMethod &&
+            SymbolEqualityComparer.Default.Equals(roslynMethod._symbol, _symbol);
+
+        public string Name => _symbol.Name;
+
+        public bool IsPublic => true;
+
+        public bool IsStatic => false;
+
+        public IXamlType ReturnType => new RoslynType((INamedTypeSymbol) _symbol.ReturnType, _assembly);
+
+        public IReadOnlyList<IXamlType> Parameters =>
+            _symbol.Parameters.Select(parameter => parameter.Type)
+                .OfType<INamedTypeSymbol>()
+                .Select(type => new RoslynType(type, _assembly))
+                .ToList();
+
+        public IXamlType DeclaringType => new RoslynType((INamedTypeSymbol)_symbol.ReceiverType, _assembly);
+
+        public IXamlMethod MakeGenericMethod(IReadOnlyList<IXamlType> typeArguments) => null;
+
+        public IReadOnlyList<IXamlCustomAttribute> CustomAttributes { get; } = new List<IXamlCustomAttribute>();
+    }
+}

Robust.Client.NameGenerator/XamlUiPartialClassGenerator.cs

@@ -0,0 +1,251 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.Text;
+using XamlX.Ast;
+using XamlX.Emit;
+using XamlX.IL;
+using XamlX.Parsers;
+using XamlX.Transform;
+using XamlX.Transform.Transformers;
+using XamlX.TypeSystem;
+
+namespace Robust.Client.NameGenerator
+{
+    /// <summary>
+    /// Based on https://github.com/AvaloniaUI/Avalonia.NameGenerator/blob/ecc9677a23de5cbc90af07ccac14e31c0da41d6a/src/Avalonia.NameGenerator/NameReferenceGenerator.cs
+    /// Adjusted for our UI-Framework & needs.
+    /// </summary>
+    [Generator]
+    public class XamlUiPartialClassGenerator : ISourceGenerator
+    {
+        private const string AttributeName = "Robust.Client.AutoGenerated.GenerateTypedNameReferencesAttribute";
+        private const string AttributeFile = "GenerateTypedNameReferencesAttribute";
+        private const string AttributeCode = @"// <auto-generated />
+using System;
+namespace Robust.Client.AutoGenerated
+{
+    [AttributeUsage(AttributeTargets.Class, Inherited = false, AllowMultiple = false)]
+    public sealed class GenerateTypedNameReferencesAttribute : Attribute { }
+}
+";
+
+        class NameVisitor : IXamlAstVisitor
+        {
+            private List<(string name, string type)> _names = new List<(string name, string type)>();
+
+            public static List<(string name, string type)> GetNames(IXamlAstNode node)
+            {
+                var visitor = new NameVisitor();
+                node.Visit(visitor);
+                return visitor._names;
+            }
+
+            private bool IsControl(IXamlType type) => type.FullName != "System.Object" &&
+                                                      (type.FullName == "Robust.Client.UserInterface.Control" ||
+                                                       IsControl(type.BaseType));
+
+            public IXamlAstNode Visit(IXamlAstNode node)
+            {
+                if (node is XamlAstObjectNode objectNode)
+                {
+                    var clrtype = objectNode.Type.GetClrType();
+                    var isControl = IsControl(clrtype);
+                        //clrtype.Interfaces.Any(i =>
+                        //i.IsInterface && i.FullName == "Robust.Client.UserInterface.IControl");
+
+                    if (!isControl)
+                        return node;
+
+                    foreach (var child in objectNode.Children)
+                    {
+                        if (child is XamlAstXamlPropertyValueNode propertyValueNode &&
+                            propertyValueNode.Property is XamlAstNamePropertyReference namedProperty &&
+                            namedProperty.Name == "Name" &&
+                            propertyValueNode.Values.Count > 0 &&
+                            propertyValueNode.Values[0] is XamlAstTextNode text)
+                        {
+                            var reg = (text.Text, $@"{clrtype.Namespace}.{clrtype.Name}");
+                            if (!_names.Contains(reg))
+                            {
+                                _names.Add(reg);
+                            }
+                        }
+                    }
+                }
+
+                return node;
+            }
+
+            public void Push(IXamlAstNode node) { }
+
+            public void Pop() { }
+        }
+
+        private static string GenerateSourceCode(
+            INamedTypeSymbol classSymbol,
+            string xamlFile,
+            CSharpCompilation comp)
+        {
+            var className = classSymbol.Name;
+            var nameSpace = classSymbol.ContainingNamespace.ToDisplayString();
+            var parsed = XDocumentXamlParser.Parse(xamlFile);
+            var typeSystem = new RoslynTypeSystem(comp);
+            var compiler =
+                new XamlILCompiler(
+                    new TransformerConfiguration(typeSystem, typeSystem.Assemblies[0],
+                        new XamlLanguageTypeMappings(typeSystem)),
+                    new XamlLanguageEmitMappings<IXamlILEmitter, XamlILNodeEmitResult>(), false);
+            compiler.Transformers.Add(new TypeReferenceResolver());
+            compiler.Transform(parsed);
+            var initialRoot = (XamlAstObjectNode) parsed.Root;
+            var names = NameVisitor.GetNames(initialRoot);
+            //var names = NameVisitor.GetNames((XamlAstObjectNode)XDocumentXamlParser.Parse(xamlFile).Root);
+            var namedControls = names.Select(info => "        " +
+                                $"protected global::{info.type} {info.name} => " +
+                                $"this.FindControl<global::{info.type}>(\"{info.name}\");");
+            return $@"// <auto-generated />
+using Robust.Client.UserInterface;
+using Robust.Client.UserInterface.Controls;
+namespace {nameSpace}
+{{
+    partial class {className}
+    {{
+{string.Join("\n", namedControls)}
+    }}
+}}
+";
+        }
+
+
+        public void Execute(GeneratorExecutionContext context)
+        {
+            var comp = (CSharpCompilation) context.Compilation;
+            if(comp.GetTypeByMetadataName(AttributeName) == null)
+                context.AddSource(AttributeFile, SourceText.From(AttributeCode, Encoding.UTF8));
+            if (!(context.SyntaxReceiver is NameReferenceSyntaxReceiver receiver))
+            {
+                return;
+            }
+
+            var symbols = UnpackAnnotatedTypes(context, comp, receiver);
+            if(symbols == null)
+                return;
+
+            foreach (var typeSymbol in symbols)
+            {
+                var xamlFileName = $"{typeSymbol.Name}.xaml";
+                var relevantXamlFile = context.AdditionalFiles.FirstOrDefault(t => t.Path.EndsWith(xamlFileName));
+
+                if (relevantXamlFile == null)
+                {
+                    context.ReportDiagnostic(
+                        Diagnostic.Create(
+                            new DiagnosticDescriptor(
+                                "RXN0001",
+                                $"Unable to discover the relevant Robust XAML file for {typeSymbol}.",
+                                "Unable to discover the relevant Robust XAML file " +
+                                $"expected at {xamlFileName}",
+                                "Usage",
+                                DiagnosticSeverity.Error,
+                                true),
+                            typeSymbol.Locations[0]));
+                    return;
+                }
+
+                var txt = relevantXamlFile.GetText()?.ToString();
+                if (txt == null)
+                {
+                    context.ReportDiagnostic(
+                        Diagnostic.Create(
+                            new DiagnosticDescriptor(
+                                "RXN0002",
+                                $"Unexpected empty Xaml-File was found at {xamlFileName}",
+                                "Expected Content due to a Class with the same name being annotated with [GenerateTypedNameReferences].",
+                                "Usage",
+                                DiagnosticSeverity.Error,
+                                true),
+                            Location.Create(xamlFileName, new TextSpan(0,0), new LinePositionSpan(new LinePosition(0,0),new LinePosition(0,0)))));
+                    return;
+                }
+
+                try
+                {
+                    var sourceCode = GenerateSourceCode(typeSymbol, txt, comp);
+                    context.AddSource($"{typeSymbol.Name}.g.cs", SourceText.From(sourceCode, Encoding.UTF8));
+                }
+                catch (Exception e)
+                {
+                    context.ReportDiagnostic(
+                        Diagnostic.Create(
+                            new DiagnosticDescriptor(
+                                "AXN0003",
+                                "Unhandled exception occured while generating typed Name references.",
+                                $"Unhandled exception occured while generating typed Name references: {e}",
+                                "Usage",
+                                DiagnosticSeverity.Error,
+                                true),
+                            typeSymbol.Locations[0]));
+                    return;
+                }
+            }
+        }
+
+        private IReadOnlyList<INamedTypeSymbol> UnpackAnnotatedTypes(in GeneratorExecutionContext context, CSharpCompilation comp, NameReferenceSyntaxReceiver receiver)
+        {
+            var options = (CSharpParseOptions) comp.SyntaxTrees[0].Options;
+            var compilation =
+                comp.AddSyntaxTrees(CSharpSyntaxTree.ParseText(SourceText.From(AttributeCode, Encoding.UTF8), options));
+            var symbols = new List<INamedTypeSymbol>();
+            var attributeSymbol = compilation.GetTypeByMetadataName(AttributeName);
+            foreach (var candidateClass in receiver.CandidateClasses)
+            {
+                var model = compilation.GetSemanticModel(candidateClass.SyntaxTree);
+                var typeSymbol = (INamedTypeSymbol) model.GetDeclaredSymbol(candidateClass);
+                var relevantAttribute = typeSymbol.GetAttributes().FirstOrDefault(attr =>
+                    attr.AttributeClass != null &&
+                    attr.AttributeClass.Equals(attributeSymbol, SymbolEqualityComparer.Default));
+
+                if (relevantAttribute == null)
+                {
+                    continue;
+                }
+
+                var isPartial = candidateClass.Modifiers.Any(m => m.IsKind(SyntaxKind.PartialKeyword));
+
+                if (isPartial)
+                {
+                    symbols.Add(typeSymbol);
+                }
+                else
+                {
+                    var missingPartialKeywordMessage =
+                        $"The type {typeSymbol.Name} should be declared with the 'partial' keyword " +
+                        "as it is annotated with the [GenerateTypedNameReferences] attribute.";
+
+                    context.ReportDiagnostic(
+                        Diagnostic.Create(
+                            new DiagnosticDescriptor(
+                                "RXN0004",
+                                missingPartialKeywordMessage,
+                                missingPartialKeywordMessage,
+                                "Usage",
+                                DiagnosticSeverity.Error,
+                                true),
+                            Location.None));
+                    return null;
+                }
+            }
+
+            return symbols;
+        }
+
+        public void Initialize(GeneratorInitializationContext context)
+        {
+            context.RegisterForSyntaxNotifications(() => new NameReferenceSyntaxReceiver());
+        }
+    }
+}

Robust.Client/Audio/Midi/MidiManager.cs

@@ -104,7 +104,7 @@ namespace Robust.Client.Audio.Midi
         private const string OsxSoundfont =
             "/System/Library/Components/CoreAudio.component/Contents/Resources/gs_instruments.dls";
 
-        private const string FallbackSoundfont = "/Resources/Midi/fallback.sf2";
+        private const string FallbackSoundfont = "/Midi/fallback.sf2";
 
         private readonly ResourceLoaderCallbacks _soundfontLoaderCallbacks = new();
 
@@ -207,13 +207,10 @@ namespace Robust.Client.Audio.Midi
 
                 var renderer = new MidiRenderer(_settings!, soundfontLoader);
 
-                foreach (var file in _resourceManager.ContentFindFiles(new ResourcePath("/Audio/MidiCustom/")))
+                foreach (var file in _resourceManager.ContentFindFiles(("/Audio/MidiCustom/")))
                 {
                     if (file.Extension != "sf2" && file.Extension != "dls") continue;
-                    if (_resourceManager.TryGetDiskFilePath(file, out var path))
-                    {
-                        renderer.LoadSoundfont(path);
-                    }
+                    renderer.LoadSoundfont(file.ToString());
                 }
 
                 // Since the last loaded soundfont takes priority, we load the fallback soundfont before the soundfont.
@@ -382,10 +379,18 @@ namespace Robust.Client.Audio.Midi
 
             public override IntPtr Open(string filename)
             {
-                Stream? stream;
-                if (filename.StartsWith("/Resources/"))
+                if (string.IsNullOrEmpty(filename))
                 {
-                    if (!IoCManager.Resolve<IResourceCache>().TryContentFileRead(filename.Substring(10), out stream))
+                    return IntPtr.Zero;
+                }
+
+                Stream? stream;
+                var resourceCache = IoCManager.Resolve<IResourceCache>();
+                var resourcePath = new ResourcePath(filename);
+
+                if (resourcePath.IsRooted && resourceCache.ContentFileExists(filename))
+                {
+                    if (!resourceCache.TryContentFileRead(filename, out stream))
                         return IntPtr.Zero;
                 }
                 else if (File.Exists(filename))

Robust.Client/BaseClient.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Net;
 using Robust.Client.Interfaces;
 using Robust.Client.Interfaces.Debugging;
@@ -7,8 +7,8 @@ using Robust.Client.Interfaces.GameStates;
 using Robust.Client.Interfaces.Utility;
 using Robust.Client.Player;
 using Robust.Shared;
+using Robust.Shared.Configuration;
 using Robust.Shared.Enums;
-using Robust.Shared.Interfaces.Configuration;
 using Robust.Shared.Interfaces.Map;
 using Robust.Shared.Interfaces.Network;
 using Robust.Shared.Interfaces.Timing;
@@ -25,7 +25,7 @@ namespace Robust.Client
     {
         [Dependency] private readonly IClientNetManager _net = default!;
         [Dependency] private readonly IPlayerManager _playMan = default!;
-        [Dependency] private readonly IConfigurationManager _configManager = default!;
+        [Dependency] private readonly INetConfigurationManager _configManager = default!;
         [Dependency] private readonly IClientEntityManager _entityManager = default!;
         [Dependency] private readonly IMapManager _mapManager = default!;
         [Dependency] private readonly IDiscordRichPresence _discord = default!;
@@ -50,9 +50,7 @@ namespace Robust.Client
         /// <inheritdoc />
         public void Initialize()
         {
-            _net.RegisterNetMessage<MsgServerInfo>(MsgServerInfo.NAME, HandleServerInfo);
             _net.RegisterNetMessage<MsgSetTickRate>(MsgSetTickRate.NAME, HandleSetTickRate);
-            _net.RegisterNetMessage<MsgServerInfoReq>(MsgServerInfoReq.NAME);
             _net.Connected += OnConnected;
             _net.ConnectFailed += OnConnectFailed;
             _net.Disconnect += OnNetDisconnect;
@@ -98,9 +96,44 @@ namespace Robust.Client
 
         private void OnConnected(object? sender, NetChannelArgs args)
         {
-            // request base info about the server
-            var msgInfo = _net.CreateNetMessage<MsgServerInfoReq>();
-            _net.ClientSendMessage(msgInfo);
+            _configManager.SyncWithServer();
+            _configManager.ReceivedInitialNwVars += OnReceivedClientData;
+        }
+
+        private void OnReceivedClientData(object? sender, EventArgs e)
+        {
+            _configManager.ReceivedInitialNwVars -= OnReceivedClientData;
+
+            var info = GameInfo;
+
+            var serverName = _configManager.GetCVar<string>("game.hostname");
+            if (info == null)
+            {
+                GameInfo = info = new ServerInfo(serverName);
+            }
+            else
+            {
+                info.ServerName = serverName;
+            }
+
+            var maxPlayers = _configManager.GetCVar<int>("game.maxplayers");
+            info.ServerMaxPlayers = maxPlayers;
+
+            var tickrate = _configManager.GetCVar<int>("net.tickrate");
+            info.TickRate = (byte) tickrate;
+            _timing.TickRate = (byte) tickrate;
+            Logger.InfoS("client", $"Tickrate changed to: {tickrate}");
+            
+            var userName = _net.ServerChannel!.UserName;
+            var userId = _net.ServerChannel.UserId;
+            _discord.Update(info.ServerName, userName, info.ServerMaxPlayers.ToString());
+            // start up player management
+            _playMan.Startup(_net.ServerChannel!);
+
+            _playMan.LocalPlayer!.UserId = userId;
+            _playMan.LocalPlayer.Name = userName;
+
+            _playMan.LocalPlayer.StatusChanged += OnLocalStatusChanged;
         }
 
         /// <summary>
@@ -152,6 +185,7 @@ namespace Robust.Client
 
             LastDisconnectReason = args.Reason;
 
+            IoCManager.Resolve<INetConfigurationManager>().FlushMessages();
             _gameStates.Reset();
             _playMan.Shutdown();
             _entityManager.Shutdown();
@@ -160,36 +194,6 @@ namespace Robust.Client
             Reset();
         }
 
-        private void HandleServerInfo(MsgServerInfo msg)
-        {
-            var info = GameInfo;
-
-            if (info == null)
-            {
-                GameInfo = info = new ServerInfo(msg.ServerName);
-            }
-            else
-            {
-                info.ServerName = msg.ServerName;
-            }
-
-            info.ServerMaxPlayers = msg.ServerMaxPlayers;
-            info.TickRate = msg.TickRate;
-            _timing.TickRate = msg.TickRate;
-            Logger.InfoS("client", $"Tickrate changed to: {msg.TickRate}");
-
-            var userName = msg.MsgChannel.UserName;
-            var userId = msg.MsgChannel.UserId;
-            _discord.Update(info.ServerName, userName, info.ServerMaxPlayers.ToString());
-            // start up player management
-            _playMan.Startup(_net.ServerChannel!);
-
-            _playMan.LocalPlayer!.UserId = userId;
-            _playMan.LocalPlayer.Name = userName;
-
-            _playMan.LocalPlayer.StatusChanged += OnLocalStatusChanged;
-        }
-
         private void HandleSetTickRate(MsgSetTickRate message)
         {
             _timing.TickRate = message.NewTickRate;

Robust.Client/ClientIoC.cs

@@ -115,6 +115,7 @@ namespace Robust.Client
             IoCManager.Register<IViewVariablesManagerInternal, ViewVariablesManager>();
             IoCManager.Register<IClientConGroupController, ClientConGroupController>();
             IoCManager.Register<IScriptClient, ScriptClient>();
+            //IoCManager.Register<IXamlCompiler, XamlCompiler>();
         }
     }
 }

Robust.Client/Console/Commands/AddCompCommand.cs

@@ -0,0 +1,72 @@
+using JetBrains.Annotations;
+using Robust.Client.Interfaces.Console;
+using Robust.Client.Player;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.IoC;
+
+namespace Robust.Client.Console.Commands
+{
+    [UsedImplicitly]
+    internal sealed class AddCompCommand : IConsoleCommand
+    {
+        public string Command => "addcompc";
+        public string Description => "Adds a component to an entity on the client";
+        public string Help => "addcompc <uid> <componentName>";
+
+        public bool Execute(IDebugConsole shell, params string[] args)
+        {
+
+            if (args.Length != 2)
+            {
+                shell.AddLine("Wrong number of arguments");
+                return false;
+            }
+
+            var entityUid = EntityUid.Parse(args[0]);
+            var componentName = args[1];
+
+            var compManager = IoCManager.Resolve<IComponentManager>();
+            var compFactory = IoCManager.Resolve<IComponentFactory>();
+            var entityManager = IoCManager.Resolve<IEntityManager>();
+
+            var entity = entityManager.GetEntity(entityUid);
+            var component = (Component) compFactory.GetComponent(componentName);
+
+            component.Owner = entity;
+
+            compManager.AddComponent(entity, component);
+
+            return false;
+        }
+    }
+
+    [UsedImplicitly]
+    internal sealed class RemoveCompCommand : IConsoleCommand
+    {
+        public string Command => "rmcompc";
+        public string Description => "Removes a component from an entity.";
+        public string Help => "rmcompc <uid> <componentName>";
+
+        public bool Execute(IDebugConsole shell, string[] args)
+        {
+            if (args.Length != 2)
+            {
+                shell.AddLine("Wrong number of arguments");
+                return false;
+            }
+
+            var entityUid = EntityUid.Parse(args[0]);
+            var componentName = args[1];
+
+            var compManager = IoCManager.Resolve<IComponentManager>();
+            var compFactory = IoCManager.Resolve<IComponentFactory>();
+
+            var registration = compFactory.GetRegistration(componentName);
+
+            compManager.RemoveComponent(entityUid, registration.Type);
+
+            return false;
+        }
+    }
+}

Robust.Client/Console/Commands/Debug.cs

@@ -781,6 +781,21 @@ namespace Robust.Client.Console.Commands
         }
     }
 
+    internal class GcFullCommand : IConsoleCommand
+    {
+        public string Command => "gcf";
+        public string Description => "Run the GC, fully, compacting LOH and everything.";
+        public string Help => "gcf";
+
+        public bool Execute(IDebugConsole console, params string[] args)
+        {
+            GCSettings.LargeObjectHeapCompactionMode = GCLargeObjectHeapCompactionMode.CompactOnce;
+            GC.Collect(2, GCCollectionMode.Forced, true, true);
+
+            return false;
+        }
+    }
+
     internal class GcModeCommand : IConsoleCommand
     {
 

Robust.Client/Console/Commands/LauncherAuthCommand.cs

@@ -0,0 +1,69 @@
+#if !FULL_RELEASE
+using System.IO;
+using System.Linq;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Robust.Client.Interfaces.Console;
+using Robust.Client.Utility;
+using Robust.Shared;
+using Robust.Shared.Interfaces.Configuration;
+using Robust.Shared.IoC;
+
+namespace Robust.Client.Console.Commands
+{
+    internal sealed class LauncherAuthCommand : IConsoleCommand
+    {
+        public string Command => "launchauth";
+        public string Description => "Load authentication tokens from launcher data to aid in testing of live servers";
+        public string Help => "launchauth [account name]";
+
+        public bool Execute(IDebugConsole console, params string[] args)
+        {
+            var wantName = args.Length > 0 ? args[0] : null;
+
+            var basePath = Path.GetDirectoryName(UserDataDir.GetUserDataDir())!;
+            var cfgPath = Path.Combine(basePath, "launcher", "launcher_config.json");
+
+            var data = JsonSerializer.Deserialize<LauncherConfig>(File.ReadAllText(cfgPath))!;
+
+            var login = wantName != null
+                ? data.Logins.FirstOrDefault(p => p.Username == wantName)
+                : data.Logins.FirstOrDefault();
+
+            if (login == null)
+            {
+                console.AddLine("Unable to find a matching login");
+                return false;
+            }
+
+            var token = login.Token.Token;
+            var userId = login.UserId;
+
+            var cfg = IoCManager.Resolve<IConfigurationManagerInternal>();
+            cfg.SetSecureCVar(CVars.AuthUserId, userId);
+            cfg.SetSecureCVar(CVars.AuthToken, token);
+
+            return false;
+        }
+
+        private sealed class LauncherConfig
+        {
+            [JsonInclude] [JsonPropertyName("logins")]
+            public LauncherLogin[] Logins = default!;
+        }
+
+        private sealed class LauncherLogin
+        {
+            [JsonInclude] public string Username = default!;
+            [JsonInclude] public string UserId = default!;
+            [JsonInclude] public LauncherToken Token = default!;
+        }
+
+        private sealed class LauncherToken
+        {
+            [JsonInclude] public string Token = default!;
+        }
+    }
+}
+
+#endif

Robust.Client/Console/Commands/SetInputContextCommand.cs

@@ -0,0 +1,35 @@
+using JetBrains.Annotations;
+using Robust.Client.Interfaces.Console;
+using Robust.Client.Interfaces.Input;
+using Robust.Shared.IoC;
+
+namespace Robust.Client.Console.Commands
+{
+    [UsedImplicitly]
+    public class SetInputContextCommand : IConsoleCommand
+    {
+        public string Command => "setinputcontext";
+        public string Description => "Sets the active input context.";
+        public string Help => "setinputcontext <context>";
+
+        public bool Execute(IDebugConsole console, params string[] args)
+        {
+            if (args.Length != 1)
+            {
+                console.AddLine("Invalid number of arguments!");
+                return false;
+            }
+
+            var inputMan = IoCManager.Resolve<IInputManager>();
+
+            if (!inputMan.Contexts.Exists(args[0]))
+            {
+                console.AddLine("Context not found!");
+                return false;
+            }
+
+            inputMan.Contexts.SetActiveContext(args[0]);
+            return false;
+        }
+    }
+}

Robust.Client/GameController.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 using System.Net;
 using System.Threading.Tasks;
@@ -164,6 +164,7 @@ namespace Robust.Client
 
             _userInterfaceManager.Initialize();
             _networkManager.Initialize(false);
+            IoCManager.Resolve<INetConfigurationManager>().SetupNetworking();
             _serializer.Initialize();
             _inputManager.Initialize();
             _console.Initialize();

Robust.Client/GameObjects/Components/Animations/AnimationPlayerComponent.cs

@@ -48,11 +48,21 @@ namespace Robust.Client.GameObjects.Components.Animations
                 return;
             }
 
+            List<string>? toRemove = null;
             // TODO: Get rid of this ToArray() allocation.
             foreach (var (key, playback) in _playingAnimations.ToArray())
             {
                 var keep = UpdatePlayback(Owner, playback, frameTime);
                 if (!keep)
+                {
+                    toRemove ??= new List<string>();
+                    toRemove.Add(key);
+                }
+            }
+
+            if (toRemove != null)
+            {
+                foreach (var key in toRemove)
                 {
                     _playingAnimations.Remove(key);
                     AnimationCompleted?.Invoke(key);

Robust.Client/GameObjects/Components/Appearance/AppearanceComponent.cs

@@ -54,17 +54,17 @@ namespace Robust.Client.GameObjects
             return (T) data[key];
         }
 
-        public override bool TryGetData<T>(Enum key, [MaybeNullWhen(false)] out T data)
+        public override bool TryGetData<T>(Enum key, [NotNullWhen(true)] out T data)
         {
             return TryGetData(key, out data);
         }
 
-        public override bool TryGetData<T>(string key, [MaybeNullWhen(false)] out T data)
+        public override bool TryGetData<T>(string key, [NotNullWhen(true)] out T data)
         {
             return TryGetData(key, out data);
         }
 
-        internal bool TryGetData<T>(object key, [MaybeNullWhen(false)] out T data)
+        internal bool TryGetData<T>(object key, [NotNullWhen(true)] out T data)
         {
             if (this.data.TryGetValue(key, out var dat))
             {
@@ -72,7 +72,7 @@ namespace Robust.Client.GameObjects
                 return true;
             }
 
-            data = default;
+            data = default!;
             return false;
         }
 

Robust.Client/GameObjects/Components/Light/PointLightComponent.cs

@@ -83,6 +83,18 @@ namespace Robust.Client.GameObjects
             set => _energy = value;
         }
 
+        /// <summary>
+        ///     Soft shadow strength multiplier.
+        ///     Has no effect if soft shadows are not enabled.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)]
+        [Animatable]
+        public float Softness
+        {
+            get => _softness;
+            set => _softness = value;
+        }
+
         [ViewVariables(VVAccess.ReadWrite)]
         public bool VisibleNested
         {
@@ -115,6 +127,7 @@ namespace Robust.Client.GameObjects
         private bool _maskAutoRotate;
         private Angle _rotation;
         private float _energy;
+        private float _softness;
 
         /// <summary>
         ///     Radius, in meters.
@@ -167,6 +180,7 @@ namespace Robust.Client.GameObjects
             serializer.DataFieldCached(ref _color, "color", Color.White);
             serializer.DataFieldCached(ref _enabled, "enabled", true);
             serializer.DataFieldCached(ref _energy, "energy", 1f);
+            serializer.DataFieldCached(ref _softness, "softness", 1f);
             serializer.DataFieldCached(ref _maskAutoRotate, "autoRot", false);
             serializer.DataFieldCached(ref _visibleNested, "nestedvisible", true);
 

Robust.Client/GameObjects/Components/Renderable/SpriteComponent.cs

@@ -991,6 +991,9 @@ namespace Robust.Client.GameObjects
             var mRotation = Matrix3.CreateRotation(angle);
             Matrix3.Multiply(ref mRotation, ref mOffset, out var transform);
 
+            // Only apply scale if needed.
+            if(!Scale.EqualsApprox(Vector2.One)) transform.Multiply(Matrix3.CreateScale(Scale));
+
             transform.Multiply(worldTransform);
 
             RenderInternal(drawingHandle, worldRotation, overrideDirection, transform);

Robust.Client/GameObjects/EntitySystems/InputSystem.cs

@@ -128,7 +128,8 @@ namespace Robust.Client.GameObjects.EntitySystems
 
             if (!entity.TryGetComponent(out InputComponent? inputComp))
             {
-                Logger.DebugS("input.context", $"AttachedEnt has no InputComponent: entId={entity.Uid}, entProto={entity.Prototype}");
+                Logger.DebugS("input.context", $"AttachedEnt has no InputComponent: entId={entity.Uid}, entProto={entity.Prototype}. Setting default \"{InputContextContainer.DefaultContextName}\" context...");
+                inputMan.Contexts.SetActiveContext(InputContextContainer.DefaultContextName);
                 return;
             }
 
@@ -138,7 +139,8 @@ namespace Robust.Client.GameObjects.EntitySystems
             }
             else
             {
-                Logger.ErrorS("input.context", $"Unknown context: entId={entity.Uid}, entProto={entity.Prototype}, context={inputComp.ContextName}");
+                Logger.ErrorS("input.context", $"Unknown context: entId={entity.Uid}, entProto={entity.Prototype}, context={inputComp.ContextName}. . Setting default \"{InputContextContainer.DefaultContextName}\" context...");
+                inputMan.Contexts.SetActiveContext(InputContextContainer.DefaultContextName);
             }
         }
 

Robust.Client/GameObjects/EntitySystems/TransformSystem.cs

@@ -16,7 +16,7 @@ namespace Robust.Client.GameObjects.EntitySystems
     ///     Handles interpolation of transform positions.
     /// </summary>
     [UsedImplicitly]
-    internal sealed class TransformSystem : EntitySystem
+    internal sealed class TransformSystem : SharedTransformSystem
     {
         // Max distance per tick how far an entity can move before it is considered teleporting.
         // TODO: Make these values somehow dependent on server TPS.

Robust.Client/GameStates/ClientGameStateManager.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using Robust.Client.GameObjects.EntitySystems;
 using Robust.Client.Interfaces;
@@ -11,6 +11,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Network.Messages;
 using Robust.Client.Player;
 using Robust.Shared;
+using Robust.Shared.Configuration;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Input;
 using Robust.Shared.Interfaces.Configuration;
@@ -41,7 +42,7 @@ namespace Robust.Client.GameStates
         [Dependency] private readonly IBaseClient _client = default!;
         [Dependency] private readonly IMapManager _mapManager = default!;
         [Dependency] private readonly IGameTiming _timing = default!;
-        [Dependency] private readonly IConfigurationManager _config = default!;
+        [Dependency] private readonly INetConfigurationManager _config = default!;
         [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
         [Dependency] private readonly IComponentManager _componentManager = default!;
         [Dependency] private readonly IInputManager _inputManager = default!;
@@ -57,7 +58,8 @@ namespace Robust.Client.GameStates
 
         public bool Predicting { get; private set; }
 
-        public int PredictSize { get; private set; }
+        public int PredictTickBias { get; private set; }
+        public float PredictLagBias { get; private set; }
 
         public int StateBufferMergeThreshold { get; private set; }
 
@@ -82,14 +84,16 @@ namespace Robust.Client.GameStates
             _config.OnValueChanged(CVars.NetInterpRatio, i => _processor.InterpRatio = i, true);
             _config.OnValueChanged(CVars.NetLogging, b => _processor.Logging = b, true);
             _config.OnValueChanged(CVars.NetPredict, b => Predicting = b, true);
-            _config.OnValueChanged(CVars.NetPredictSize, i => PredictSize = i, true);
+            _config.OnValueChanged(CVars.NetPredictTickBias, i => PredictTickBias = i, true);
+            _config.OnValueChanged(CVars.NetPredictLagBias, i => PredictLagBias = i, true);
             _config.OnValueChanged(CVars.NetStateBufMergeThreshold, i => StateBufferMergeThreshold = i, true);
 
             _processor.Interpolation = _config.GetCVar(CVars.NetInterp);
             _processor.InterpRatio = _config.GetCVar(CVars.NetInterpRatio);
             _processor.Logging = _config.GetCVar(CVars.NetLogging);
             Predicting = _config.GetCVar(CVars.NetPredict);
-            PredictSize = _config.GetCVar(CVars.NetPredictSize);
+            PredictTickBias = _config.GetCVar(CVars.NetPredictTickBias);
+            PredictLagBias = _config.GetCVar(CVars.NetPredictLagBias);
         }
 
         /// <inheritdoc />
@@ -174,7 +178,7 @@ namespace Robust.Client.GameStates
             var i = 0;
             for (; i < applyCount; i++)
             {
-                _timing.CurTick = _lastProcessedTick + 1;
+                _timing.LastRealTick = _timing.CurTick = _lastProcessedTick + 1;
 
                 // TODO: We could theoretically communicate with the GameStateProcessor better here.
                 // Since game states are sliding windows, it is possible that we need less than applyCount applies here.
@@ -256,9 +260,9 @@ namespace Robust.Client.GameStates
             var hasPendingInput = pendingInputEnumerator.MoveNext();
             var hasPendingMessage = pendingMessagesEnumerator.MoveNext();
 
-            var ping = _network.ServerChannel!.Ping / 1000f; // seconds.
+            var ping = _network.ServerChannel!.Ping / 1000f + PredictLagBias; // seconds.
             var targetTick = _timing.CurTick.Value + _processor.TargetBufferSize +
-                             (int) Math.Ceiling(_timing.TickRate * ping) + PredictSize;
+                             (int) Math.Ceiling(_timing.TickRate * ping) + PredictTickBias;
 
             // Logger.DebugS("net.predict", $"Predicting from {_lastProcessedTick} to {targetTick}");
 
@@ -377,6 +381,7 @@ namespace Robust.Client.GameStates
 
         private List<EntityUid> ApplyGameState(GameState curState, GameState? nextState)
         {
+            _config.TickProcessMessages();
             _mapManager.ApplyGameStatePre(curState.MapData);
             var createdEntities = _entities.ApplyEntityStates(curState.EntityStates, curState.EntityDeletions,
                 nextState?.EntityStates);

Robust.Client/Graphics/Clyde/Audio/Clyde.AudioFormats.OggVorbis.cs

@@ -18,7 +18,7 @@ namespace Robust.Client.Graphics.Clyde
 
                 while (readSamples < totalSamples)
                 {
-                    var read = vorbis.ReadSamples(buffer, readSamples * channels, (int)totalSamples - readSamples);
+                    var read = vorbis.ReadSamples(buffer, readSamples * channels, buffer.Length - readSamples);
                     if (read == 0)
                     {
                         break;

Robust.Client/Graphics/Clyde/Clyde.DllMap.cs

@@ -11,6 +11,22 @@ namespace Robust.Client.Graphics.Clyde
     {
         static Clyde()
         {
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows) &&
+                RuntimeInformation.ProcessArchitecture == Architecture.X64)
+            {
+                try
+                {
+                    // We force load nvapi64.dll so nvidia gives us the dedicated GPU on optimus laptops.
+                    // This is 100x easier than nvidia's documented approach of NvOptimusEnablement,
+                    // and works while developing.
+                    NativeLibrary.Load("nvapi64.dll");
+                }
+                catch (Exception)
+                {
+                    // If this fails whatever.
+                }
+            }
+
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
                 return;

Robust.Client/Graphics/Clyde/Clyde.LightRendering.cs

@@ -377,6 +377,7 @@ namespace Robust.Client.Graphics.Clyde
             var lastRange = float.NaN;
             var lastPower = float.NaN;
             var lastColor = new Color(float.NaN, float.NaN, float.NaN, float.NaN);
+            var lastSoftness = float.NaN;
             Texture? lastMask = null;
 
             for (var i = 0; i < count; i++)
@@ -424,6 +425,12 @@ namespace Robust.Client.Graphics.Clyde
                     lightShader.SetUniformMaybe("lightColor", lastColor);
                 }
 
+                if (_enableSoftShadows && !MathHelper.CloseTo(lastSoftness, component.Softness))
+                {
+                    lastSoftness = component.Softness;
+                    lightShader.SetUniformMaybe("lightSoftness", lastSoftness);
+                }
+
                 lightShader.SetUniformMaybe("lightCenter", lightPos);
                 lightShader.SetUniformMaybe("lightIndex", (i + 0.5f) / ShadowTexture.Height);
 

Robust.Client/Graphics/Clyde/Clyde.RenderTargets.cs

@@ -140,7 +140,7 @@ namespace Robust.Client.Graphics.Clyde
                 CheckGlError();
 
                 // Check on original format is NOT a bug, this is so srgb emulation works
-                textureObject = GenTexture(texture, size, format.ColorFormat == RTCF.Rgba8Srgb, name == null ? null : $"{name}-color");
+                textureObject = GenTexture(texture, size, format.ColorFormat == RTCF.Rgba8Srgb, name == null ? null : $"{name}-color", TexturePixelType.RenderTarget);
             }
 
             // Depth/stencil buffers.

Robust.Client/Graphics/Clyde/Clyde.Textures.cs

@@ -11,6 +11,9 @@ using Robust.Shared.Utility;
 using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
 using OGLTextureWrapMode = OpenToolkit.Graphics.OpenGL.TextureWrapMode;
+using PIF = OpenToolkit.Graphics.OpenGL4.PixelInternalFormat;
+using PF = OpenToolkit.Graphics.OpenGL4.PixelFormat;
+using PT = OpenToolkit.Graphics.OpenGL4.PixelType;
 
 namespace Robust.Client.Graphics.Clyde
 {
@@ -20,8 +23,7 @@ namespace Robust.Client.Graphics.Clyde
         private ClydeTexture _stockTextureBlack = default!;
         private ClydeTexture _stockTextureTransparent = default!;
 
-        private readonly Dictionary<ClydeHandle, LoadedTexture> _loadedTextures =
-            new();
+        private readonly Dictionary<ClydeHandle, LoadedTexture> _loadedTextures = new();
 
         private readonly ConcurrentQueue<ClydeHandle> _textureDisposeQueue = new();
 
@@ -69,85 +71,129 @@ namespace Robust.Client.Graphics.Clyde
             // Flip image because OpenGL reads images upside down.
             var copy = FlipClone(image);
 
-            var texture = new GLHandle((uint) GL.GenTexture());
-            CheckGlError();
-            GL.BindTexture(TextureTarget.Texture2D, texture.Handle);
-            CheckGlError();
-            ApplySampleParameters(actualParams.SampleParameters);
-
-            PixelInternalFormat internalFormat;
-            PixelFormat pixelDataFormat;
-            PixelType pixelDataType;
-            bool isActuallySrgb = false;
-
-            if (pixelType == typeof(Rgba32))
-            {
-                // Note that if _hasGLSrgb is off, we import an sRGB texture as non-sRGB.
-                // Shaders are expected to compensate for this
-                internalFormat = (actualParams.Srgb && _hasGLSrgb) ? PixelInternalFormat.Srgb8Alpha8 : PixelInternalFormat.Rgba8;
-                isActuallySrgb = actualParams.Srgb;
-                pixelDataFormat = PixelFormat.Rgba;
-                pixelDataType = PixelType.UnsignedByte;
-            }
-            else if (pixelType == typeof(A8))
-            {
-                if (image.Width % 4 != 0 || image.Height % 4 != 0)
-                {
-                    throw new ArgumentException("Alpha8 images must have multiple of 4 sizes.");
-                }
-
-                internalFormat = PixelInternalFormat.R8;
-                pixelDataFormat = PixelFormat.Red;
-                pixelDataType = PixelType.UnsignedByte;
-
-                unsafe
-                {
-                    // TODO: Does it make sense to default to 1 for RGB parameters?
-                    // It might make more sense to pass some options to change swizzling.
-                    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleR, (int) All.One);
-                    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleG, (int) All.One);
-                    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleB, (int) All.One);
-                    GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleA, (int) All.Red);
-                }
-            }
-            else if (pixelType == typeof(L8) && !actualParams.Srgb)
-            {
-                // Can only use R8 for L8 if sRGB is OFF.
-                // Because OpenGL doesn't provide sRGB single/dual channel image formats.
-                // Vulkan when?
-                if (copy.Width % 4 != 0 || copy.Height % 4 != 0)
-                {
-                    throw new ArgumentException("L8 non-sRGB images must have multiple of 4 sizes.");
-                }
-
-                internalFormat = PixelInternalFormat.R8;
-                pixelDataFormat = PixelFormat.Red;
-                pixelDataType = PixelType.UnsignedByte;
-
-                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleR, (int) All.Red);
-                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleG, (int) All.Red);
-                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleB, (int) All.Red);
-                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleA, (int) All.One);
-            }
-            else
-            {
-                throw new NotImplementedException($"Unable to handle pixel type '{pixelType.Name}'");
-            }
+            var texture = CreateBaseTextureInternal<T>(image.Width, image.Height, actualParams, name);
 
             unsafe
             {
                 var span = copy.GetPixelSpan();
                 fixed (T* ptr = span)
                 {
-                    GL.TexImage2D(TextureTarget.Texture2D, 0, internalFormat, copy.Width, copy.Height, 0,
-                        pixelDataFormat, pixelDataType, (IntPtr) ptr);
-                    CheckGlError();
+                    // Still bound.
+                    DoTexUpload(copy.Width, copy.Height, actualParams.Srgb, ptr);
                 }
             }
 
-            var pressureEst = EstPixelSize(internalFormat) * copy.Width * copy.Height;
+            return texture;
+        }
 
-            return GenTexture(texture, (copy.Width, copy.Height), isActuallySrgb, name, pressureEst);
+        public unsafe OwnedTexture CreateBlankTexture<T>(
+            Vector2i size,
+            string? name = null,
+            in TextureLoadParameters? loadParams = null)
+            where T : unmanaged, IPixel<T>
+        {
+            var actualParams = loadParams ?? TextureLoadParameters.Default;
+            if (!_hasGLTextureSwizzle)
+            {
+                // Actually create RGBA32 texture if missing texture swizzle.
+                // This is fine (TexturePixelType that's stored) because all other APIs do the same.
+                if (typeof(T) == typeof(A8) || typeof(T) == typeof(L8))
+                {
+                    return CreateBlankTexture<Rgba32>(size, name, loadParams);
+                }
+            }
+
+            var texture = CreateBaseTextureInternal<T>(
+                size.X, size.Y,
+                actualParams,
+                name);
+
+            // Texture still bound, run glTexImage2D with null data param to specify bounds.
+            DoTexUpload<T>(size.X, size.Y, actualParams.Srgb, null);
+
+            return texture;
+        }
+
+        private unsafe void DoTexUpload<T>(int width, int height, bool srgb, T* ptr) where T : unmanaged, IPixel<T>
+        {
+            if (sizeof(T) < 4)
+            {
+                GL.PixelStore(PixelStoreParameter.UnpackAlignment, 1);
+                CheckGlError();
+            }
+
+            var (pif, pf, pt) = PixelEnums<T>(srgb);
+            GL.TexImage2D(TextureTarget.Texture2D, 0, pif, width, height, 0, pf, pt, (IntPtr) ptr);
+            CheckGlError();
+
+            if (sizeof(T) < 4)
+            {
+                GL.PixelStore(PixelStoreParameter.UnpackAlignment, 4);
+                CheckGlError();
+            }
+        }
+
+        private ClydeTexture CreateBaseTextureInternal<T>(
+            int width, int height,
+            in TextureLoadParameters loadParams,
+            string? name = null)
+            where T : unmanaged, IPixel<T>
+        {
+            var texture = new GLHandle((uint) GL.GenTexture());
+            CheckGlError();
+            GL.BindTexture(TextureTarget.Texture2D, texture.Handle);
+            CheckGlError();
+            ApplySampleParameters(loadParams.SampleParameters);
+
+            var (pif, _, _) = PixelEnums<T>(loadParams.Srgb);
+            var pixelType = typeof(T);
+            var texPixType = GetTexturePixelType<T>();
+            var isActuallySrgb = false;
+
+            if (pixelType == typeof(Rgba32))
+            {
+                isActuallySrgb = loadParams.Srgb;
+            }
+            else if (pixelType == typeof(A8))
+            {
+                DebugTools.Assert(_hasGLTextureSwizzle);
+
+                // TODO: Does it make sense to default to 1 for RGB parameters?
+                // It might make more sense to pass some options to change swizzling.
+                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleR, (int) All.One);
+                CheckGlError();
+                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleG, (int) All.One);
+                CheckGlError();
+                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleB, (int) All.One);
+                CheckGlError();
+                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleA, (int) All.Red);
+                CheckGlError();
+            }
+            else if (pixelType == typeof(L8) && !loadParams.Srgb)
+            {
+                DebugTools.Assert(_hasGLTextureSwizzle);
+
+                // Can only use R8 for L8 if sRGB is OFF.
+                // Because OpenGL doesn't provide sRGB single/dual channel image formats.
+                // Vulkan when?
+
+                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleR, (int) All.Red);
+                CheckGlError();
+                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleG, (int) All.Red);
+                CheckGlError();
+                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleB, (int) All.Red);
+                CheckGlError();
+                GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureSwizzleA, (int) All.One);
+                CheckGlError();
+            }
+            else
+            {
+                throw new NotSupportedException($"Unable to handle pixel type '{pixelType.Name}'");
+            }
+
+            var pressureEst = EstPixelSize(pif) * width * height;
+
+            return GenTexture(texture, (width, height), isActuallySrgb, name, texPixType, pressureEst);
         }
 
         private void ApplySampleParameters(TextureSampleParameters? sampleParameters)
@@ -201,10 +247,30 @@ namespace Robust.Client.Graphics.Clyde
                 default:
                     throw new ArgumentOutOfRangeException();
             }
+
             CheckGlError();
         }
 
-        private ClydeTexture GenTexture(GLHandle glHandle, Vector2i size, bool srgb, string? name, long memoryPressure=0)
+        private (PIF pif, PF pf, PT pt) PixelEnums<T>(bool srgb)
+            where T : unmanaged, IPixel<T>
+        {
+            return default(T) switch
+            {
+                // Note that if _hasGLSrgb is off, we import an sRGB texture as non-sRGB.
+                // Shaders are expected to compensate for this
+                Rgba32 => (srgb && _hasGLSrgb ? PIF.Srgb8Alpha8 : PIF.Rgba8, PF.Rgba, PT.UnsignedByte),
+                A8 or L8 => (PIF.R8, PF.Red, PT.UnsignedByte),
+                _ => throw new NotSupportedException("Unsupported pixel type."),
+            };
+        }
+
+        private ClydeTexture GenTexture(
+            GLHandle glHandle,
+            Vector2i size,
+            bool srgb,
+            string? name,
+            TexturePixelType pixType,
+            long memoryPressure = 0)
         {
             if (name != null)
             {
@@ -222,7 +288,8 @@ namespace Robust.Client.Graphics.Clyde
                 Height = height,
                 IsSrgb = srgb,
                 Name = name,
-                MemoryPressure = memoryPressure
+                MemoryPressure = memoryPressure,
+                TexturePixelType = pixType
                 // TextureInstance = new WeakReference<ClydeTexture>(instance)
             };
 
@@ -246,6 +313,97 @@ namespace Robust.Client.Graphics.Clyde
             //GC.RemoveMemoryPressure(loadedTexture.MemoryPressure);
         }
 
+        private unsafe void SetSubImage<T>(
+            ClydeTexture texture,
+            Vector2i dstTl,
+            Image<T> srcImage,
+            in UIBox2i srcBox)
+            where T : unmanaged, IPixel<T>
+        {
+            if (!_hasGLTextureSwizzle)
+            {
+                if (typeof(T) == typeof(A8))
+                {
+                    SetSubImage(texture, dstTl, ApplyA8Swizzle((Image<A8>) (object) srcImage), srcBox);
+                }
+
+                if (typeof(T) == typeof(L8))
+                {
+                    SetSubImage(texture, dstTl, ApplyL8Swizzle((Image<L8>) (object) srcImage), srcBox);
+                }
+            }
+
+            var loaded = _loadedTextures[texture.TextureId];
+
+            var pixType = GetTexturePixelType<T>();
+
+            if (pixType != loaded.TexturePixelType)
+            {
+                if (loaded.TexturePixelType == TexturePixelType.RenderTarget)
+                    throw new InvalidOperationException("Cannot modify texture for render target directly.");
+
+                throw new InvalidOperationException("Mismatching pixel type for texture.");
+            }
+
+            if (loaded.Width < dstTl.X + srcBox.Width || loaded.Height < dstTl.Y + srcBox.Height)
+                throw new ArgumentOutOfRangeException(nameof(srcBox), "Destination rectangle out of bounds.");
+
+            if (srcBox.Left < 0 || srcBox.Top < 0 || srcBox.Right > srcImage.Width || srcBox.Bottom > srcImage.Height)
+                throw new ArgumentOutOfRangeException(nameof(srcBox), "Source rectangle out of bounds.");
+
+            if (sizeof(T) != 4)
+            {
+                GL.PixelStore(PixelStoreParameter.UnpackAlignment, 1);
+                CheckGlError();
+            }
+
+            // sRGB doesn't matter since that only changes the internalFormat, which we don't need here.
+            var (_, pf, pt) = PixelEnums<T>(srgb: false);
+
+            GL.BindTexture(TextureTarget.Texture2D, loaded.OpenGLObject.Handle);
+            CheckGlError();
+
+            var size = srcBox.Width * srcBox.Height;
+
+            var copyBuffer = size < 16 * 16 ? stackalloc T[size] : new T[size];
+
+            for (var y = 0; y < srcBox.Height; y++)
+            for (var x = 0; x < srcBox.Width; x++)
+            {
+                copyBuffer[(srcBox.Height - y - 1) * srcBox.Width + x] = srcImage[x + srcBox.Left, srcBox.Top + y];
+            }
+
+            fixed (T* aPtr = copyBuffer)
+            {
+                var dstY = loaded.Height - dstTl.Y - srcBox.Height;
+                GL.TexSubImage2D(
+                    TextureTarget.Texture2D,
+                    0,
+                    dstTl.X, dstY,
+                    srcBox.Width, srcBox.Height,
+                    pf, pt,
+                    (IntPtr) aPtr);
+                CheckGlError();
+            }
+
+            if (sizeof(T) != 4)
+            {
+                GL.PixelStore(PixelStoreParameter.UnpackAlignment, 4);
+                CheckGlError();
+            }
+        }
+
+        private static TexturePixelType GetTexturePixelType<T>() where T : unmanaged, IPixel<T>
+        {
+            return default(T) switch
+            {
+                Rgba32 => TexturePixelType.Rgba32,
+                L8 => TexturePixelType.L8,
+                A8 => TexturePixelType.A8,
+                _ => throw new NotSupportedException("Unsupported pixel type."),
+            };
+        }
+
         private void LoadStockTextures()
         {
             var white = new Image<Rgba32>(1, 1);
@@ -350,10 +508,20 @@ namespace Robust.Client.Graphics.Clyde
             public bool IsSrgb;
             public string? Name;
             public long MemoryPressure;
+            public TexturePixelType TexturePixelType;
+
             public Vector2i Size => (Width, Height);
             // public WeakReference<ClydeTexture> TextureInstance;
         }
 
+        private enum TexturePixelType : byte
+        {
+            RenderTarget = 0,
+            Rgba32,
+            A8,
+            L8,
+        }
+
         private void FlushTextureDispose()
         {
             while (_textureDisposeQueue.TryDequeue(out var handle))
@@ -369,6 +537,11 @@ namespace Robust.Client.Graphics.Clyde
 
             internal ClydeHandle TextureId { get; }
 
+            public override void SetSubImage<T>(Vector2i topLeft, Image<T> sourceImage, in UIBox2i sourceRegion)
+            {
+                _clyde.SetSubImage(this, topLeft, sourceImage, sourceRegion);
+            }
+
             protected override void Dispose(bool disposing)
             {
                 if (disposing)

Robust.Client/Graphics/Clyde/ClydeHeadless.cs

@@ -49,6 +49,7 @@ namespace Robust.Client.Graphics.Clyde
         public string GetKeyName(Keyboard.Key key) => string.Empty;
         public string GetKeyNameScanCode(int scanCode) => string.Empty;
         public int GetKeyScanCode(Keyboard.Key key) => default;
+
         public void Shutdown()
         {
             // Nada.
@@ -77,8 +78,8 @@ namespace Robust.Client.Graphics.Clyde
 
         public override event Action<WindowResizedEventArgs> OnWindowResized
         {
-            add {}
-            remove {}
+            add { }
+            remove { }
         }
 
         public void Render()
@@ -111,6 +112,15 @@ namespace Robust.Client.Graphics.Clyde
             return new DummyTexture((image.Width, image.Height));
         }
 
+        public OwnedTexture CreateBlankTexture<T>(
+            Vector2i size,
+            string? name = null,
+            in TextureLoadParameters? loadParams = null)
+            where T : unmanaged, IPixel<T>
+        {
+            return new DummyTexture(size);
+        }
+
         public IRenderTexture CreateRenderTarget(Vector2i size, RenderTargetFormatParameters format,
             TextureSampleParameters? sampleParameters = null, string? name = null)
         {
@@ -174,7 +184,7 @@ namespace Robust.Client.Graphics.Clyde
             return DummyAudioSource.Instance;
         }
 
-        public IClydeBufferedAudioSource CreateBufferedAudioSource(int buffers, bool floatAudio=false)
+        public IClydeBufferedAudioSource CreateBufferedAudioSource(int buffers, bool floatAudio = false)
         {
             return DummyBufferedAudioSource.Instance;
         }
@@ -296,6 +306,11 @@ namespace Robust.Client.Graphics.Clyde
             public DummyTexture(Vector2i size) : base(size)
             {
             }
+
+            public override void SetSubImage<T>(Vector2i topLeft, Image<T> sourceImage, in UIBox2i sourceRegion)
+            {
+                // Just do nothing on mutate.
+            }
         }
 
         private sealed class DummyShaderInstance : ShaderInstance
@@ -434,7 +449,8 @@ namespace Robust.Client.Graphics.Clyde
             {
             }
 
-            public IRenderTexture RenderTarget { get; } = new DummyRenderTexture(Vector2i.One, new DummyTexture(Vector2i.One));
+            public IRenderTexture RenderTarget { get; } =
+                new DummyRenderTexture(Vector2i.One, new DummyTexture(Vector2i.One));
 
             public IEye? Eye { get; set; }
             public Vector2i Size { get; }

Robust.Client/Graphics/Clyde/Shaders/shadow-depth.frag

@@ -1,24 +1,16 @@
 
-// xy: A, zw: B
-varying highp vec4 fragPos;
-// x: actual angle, y: horizontal (1) / vertical (-1)
-varying highp vec2 fragAngle;
+// x: Angle being queried, y: Angle of closest point of line (is of 90-degree angle to line angle), z: Distance at y
+varying highp vec3 fragControl;
 
 void main()
 {
-    // Stuff that needs to be inferred to avoid interpolation issues.
-    highp vec2 rayNormal = vec2(cos(fragAngle.x), -sin(fragAngle.x));
-
-    // Depth calculation accounting for interpolation.
-    highp float dist;
-
-    if (fragAngle.y > 0.0) {
-        // Line is horizontal
-        dist = abs(fragPos.y / rayNormal.y);
-    } else {
-        // Line is vertical
-        dist = abs(fragPos.x / rayNormal.x);
-    }
+    // Thanks to Radrark for finding this for me. There's also a useful diagram, but this is text, so:
+    // r = p / cos(theta - phi)
+    // r: Distance to line *given angle theta*
+    // p: Distance to closest point of line
+    // theta: Angle being queried
+    // phi: Angle of closest point of line - inherently on 90-degree angle to line angle
+    highp float dist = abs(fragControl.z / cos(fragControl.x - fragControl.y));
 
     // Main body.
 #ifdef HAS_DFDX

Robust.Client/Graphics/Clyde/Shaders/shadow-depth.vert

@@ -11,10 +11,8 @@ attribute vec4 aPos;
 // x: deflection(0=A/1=B) y: height
 attribute vec2 subVertex;
 
-// xy: A, zw: B
-varying vec4 fragPos;
-// x: actual angle, y: horizontal (1) / vertical (-1)
-varying vec2 fragAngle;
+// x: actual angle, y: line angle + 90 degrees, z: Distance at y
+varying vec3 fragControl;
 
 // Note: This is *not* the standard projectionMatrix!
 uniform vec2 shadowLightCentre;
@@ -70,8 +68,19 @@ void main()
         }
     }
 
-    fragPos = vec4(pA, pB);
-    fragAngle = vec2(mix(xA, xB, subVertex.x), abs(pA.x - pB.x) - abs(pA.y - pB.y));
+    float targetAngle = mix(xA, xB, subVertex.x);
+
+    // Calculate the necessary control data for the fragment shader.
+    vec2 lineNormal = pB - pA; // hypothetical: <- would have negative X, zero Y
+    lineNormal /= length(lineNormal);
+    fragControl = vec3(
+        // Angle
+        targetAngle,
+        // Angle Out
+        atan(lineNormal.x, lineNormal.y),
+        // Distance @ Angle Out
+        dot(vec2(lineNormal.y, -lineNormal.x), pA)
+    );
 
     // Depth divide MUST be implemented here no matter what,
     //  because GLES SL 1.00 doesn't have gl_FragDepth.
@@ -79,5 +88,5 @@ void main()
     //  and we don't really need to have correction
     float zbufferDepth = 1.0 - (1.0 / (length(mix(pA, pB, subVertex.x)) + DEPTH_ZBUFFER_PREDIV_BIAS));
 
-    gl_Position = vec4(mix(xA, xB, subVertex.x) / PI, mix(1.0, -1.0, subVertex.y), zbufferDepth, 1.0);
+    gl_Position = vec4(targetAngle / PI, mix(1.0, -1.0, subVertex.y), zbufferDepth, 1.0);
 }

Robust.Client/Graphics/FontManager.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Text;
 using JetBrains.Annotations;
 using Robust.Client.Interfaces.Graphics;
 using Robust.Client.Utility;
@@ -17,7 +18,11 @@ namespace Robust.Client.Graphics
 {
     internal sealed class FontManager : IFontManagerInternal
     {
+        private const int SheetWidth = 256;
+        private const int SheetHeight = 256;
+
         [Dependency] private readonly IConfigurationManager _configuration = default!;
+        [Dependency] private readonly IClyde _clyde = default!;
 
         private uint BaseFontDPI;
 
@@ -51,8 +56,7 @@ namespace Robust.Client.Graphics
                 return instance;
             }
 
-            var glyphMap = _generateGlyphMap(fontFaceHandle.Face);
-            instance = new FontInstanceHandle(this, size, glyphMap, fontFaceHandle);
+            instance = new FontInstanceHandle(this, size, fontFaceHandle);
 
             _loadedInstances.Add((fontFaceHandle, size), instance);
             return instance;
@@ -67,135 +71,128 @@ namespace Robust.Client.Graphics
             var descent = -ftFace.Size.Metrics.Descender.ToInt32();
             var lineHeight = ftFace.Size.Metrics.Height.ToInt32();
 
-            var (atlas, metricsMap) = _generateAtlas(instance, scale);
+            var data = new ScaledFontData(ascent, descent, ascent + descent, lineHeight);
 
-            return new ScaledFontData(metricsMap, ascent, descent, ascent + descent, lineHeight, atlas);
+
+            return data;
         }
 
-        private (FontTextureAtlas, Dictionary<uint, CharMetrics> metricsMap)
-            _generateAtlas(FontInstanceHandle instance, float scale)
+        private void CacheGlyph(FontInstanceHandle instance, ScaledFontData scaled, float scale, uint glyph)
         {
-            // TODO: This could use a better box packing algorithm.
-            // Right now we treat each glyph bitmap as having the max size among all glyphs.
-            // So we can divide the atlas into equal-size rectangles.
-            // This wastes a lot of space though because there's a lot of tiny glyphs.
+            // Check if already cached.
+            if (scaled.AtlasData.ContainsKey(glyph))
+                return;
 
             var face = instance.FaceHandle.Face;
+            face.SetCharSize(0, instance.Size, 0, (uint) (BaseFontDPI * scale));
+            face.LoadGlyph(glyph, LoadFlags.Default, LoadTarget.Normal);
+            face.Glyph.RenderGlyph(RenderMode.Normal);
 
-            var maxGlyphSize = Vector2i.Zero;
-            var count = 0;
+            var glyphMetrics = face.Glyph.Metrics;
+            var metrics = new CharMetrics(glyphMetrics.HorizontalBearingX.ToInt32(),
+                glyphMetrics.HorizontalBearingY.ToInt32(),
+                glyphMetrics.HorizontalAdvance.ToInt32(),
+                glyphMetrics.Width.ToInt32(),
+                glyphMetrics.Height.ToInt32());
 
-            var metricsMap = new Dictionary<uint, CharMetrics>();
-
-            foreach (var glyph in instance.GlyphMap.Values)
+            using var bitmap = face.Glyph.Bitmap;
+            if (bitmap.Pitch < 0)
             {
-                if (metricsMap.ContainsKey(glyph))
-                {
-                    continue;
-                }
-
-                face.LoadGlyph(glyph, LoadFlags.Default, LoadTarget.Normal);
-                face.Glyph.RenderGlyph(RenderMode.Normal);
-
-                var glyphMetrics = face.Glyph.Metrics;
-                var metrics = new CharMetrics(glyphMetrics.HorizontalBearingX.ToInt32(),
-                    glyphMetrics.HorizontalBearingY.ToInt32(),
-                    glyphMetrics.HorizontalAdvance.ToInt32(),
-                    glyphMetrics.Width.ToInt32(),
-                    glyphMetrics.Height.ToInt32());
-                metricsMap.Add(glyph, metrics);
-
-                maxGlyphSize = Vector2i.ComponentMax(maxGlyphSize,
-                    new Vector2i(face.Glyph.Bitmap.Width, face.Glyph.Bitmap.Rows));
-
-                count += 1;
+                throw new NotImplementedException();
             }
 
-            // Make atlas.
-            // This is the same algorithm used for RSIs. Tries to keep width and height as close as possible,
-            //  but preferring to increase width if necessary.
-            var atlasEntriesHorizontal = (int) Math.Ceiling(Math.Sqrt(count));
-            var atlasEntriesVertical =
-                (int) Math.Ceiling(count / (float) atlasEntriesHorizontal);
-            var atlasDimX =
-                (int) Math.Ceiling(atlasEntriesHorizontal * maxGlyphSize.X / 4f) * 4;
-            var atlasDimY =
-                (int) Math.Ceiling(atlasEntriesVertical * maxGlyphSize.Y / 4f) * 4;
-
-            using (var atlas = new Image<A8>(atlasDimX, atlasDimY))
+            if (bitmap.Pitch != 0)
             {
-                var atlasRegions = new Dictionary<uint, UIBox2>();
-                count = 0;
-                foreach (var glyph in metricsMap.Keys)
+                Image<A8> img;
+                switch (bitmap.PixelMode)
                 {
-                    face.LoadGlyph(glyph, LoadFlags.Default, LoadTarget.Normal);
-                    face.Glyph.RenderGlyph(RenderMode.Normal);
-
-                    var bitmap = face.Glyph.Bitmap;
-                    if (bitmap.Pitch == 0)
+                    case PixelMode.Mono:
                     {
-                        count += 1;
-                        continue;
+                        img = MonoBitMapToImage(bitmap);
+                        break;
                     }
 
-                    if (bitmap.Pitch < 0)
+                    case PixelMode.Gray:
                     {
+                        ReadOnlySpan<A8> span;
+                        unsafe
+                        {
+                            span = new ReadOnlySpan<A8>((void*) bitmap.Buffer, bitmap.Pitch * bitmap.Rows);
+                        }
+
+                        img = new Image<A8>(bitmap.Width, bitmap.Rows);
+
+                        span.Blit(
+                            bitmap.Pitch,
+                            UIBox2i.FromDimensions(0, 0, bitmap.Pitch, bitmap.Rows),
+                            img,
+                            (0, 0));
+
+                        break;
+                    }
+
+                    case PixelMode.Gray2:
+                    case PixelMode.Gray4:
+                    case PixelMode.Lcd:
+                    case PixelMode.VerticalLcd:
+                    case PixelMode.Bgra:
                         throw new NotImplementedException();
-                    }
-
-                    var column = count % atlasEntriesHorizontal;
-                    var row = count / atlasEntriesVertical;
-                    var offsetX = column * maxGlyphSize.X;
-                    var offsetY = row * maxGlyphSize.Y;
-                    count += 1;
-                    atlasRegions.Add(glyph, UIBox2i.FromDimensions(offsetX, offsetY, bitmap.Width, bitmap.Rows));
-
-                    switch (bitmap.PixelMode)
-                    {
-                        case PixelMode.Mono:
-                        {
-                            using (var bitmapImage = MonoBitMapToImage(bitmap))
-                            {
-                                bitmapImage.Blit(new UIBox2i(0, 0, bitmapImage.Width, bitmapImage.Height), atlas,
-                                    (offsetX, offsetY));
-                            }
-
-                            break;
-                        }
-
-                        case PixelMode.Gray:
-                        {
-                            ReadOnlySpan<A8> span;
-                            unsafe
-                            {
-                                span = new ReadOnlySpan<A8>((void*) bitmap.Buffer, bitmap.Pitch * bitmap.Rows);
-                            }
-
-                            span.Blit(bitmap.Pitch, UIBox2i.FromDimensions(0, 0, bitmap.Pitch, bitmap.Rows), atlas,
-                                (offsetX, offsetY));
-                            break;
-                        }
-
-                        case PixelMode.Gray2:
-                        case PixelMode.Gray4:
-                        case PixelMode.Lcd:
-                        case PixelMode.VerticalLcd:
-                        case PixelMode.Bgra:
-                            throw new NotImplementedException();
-                        default:
-                            throw new ArgumentOutOfRangeException();
-                    }
+                    default:
+                        throw new ArgumentOutOfRangeException();
                 }
 
-                var atlasDictionary = new Dictionary<uint, AtlasTexture>();
-                var texture = Texture.LoadFromImage(atlas, $"font-{face.FamilyName}-{instance.Size}-{(uint) (BaseFontDPI * scale)}");
+                OwnedTexture sheet;
+                if (scaled.AtlasTextures.Count == 0)
+                    sheet = GenSheet();
+                else
+                    sheet = scaled.AtlasTextures[^1];
 
-                foreach (var (glyph, region) in atlasRegions)
+                var (sheetW, sheetH) = sheet.Size;
+
+                if (sheetW - scaled.CurSheetX < img.Width)
                 {
-                    atlasDictionary.Add(glyph, new AtlasTexture(texture, region));
+                    scaled.CurSheetX = 0;
+                    scaled.CurSheetY = scaled.CurSheetMaxY;
                 }
 
-                return (new FontTextureAtlas(texture, atlasDictionary), metricsMap);
+                if (sheetH - scaled.CurSheetY < img.Height)
+                {
+                    // Make new sheet.
+                    scaled.CurSheetY = 0;
+                    scaled.CurSheetX = 0;
+                    scaled.CurSheetMaxY = 0;
+
+                    sheet = GenSheet();
+                }
+
+                sheet.SetSubImage((scaled.CurSheetX, scaled.CurSheetY), img);
+
+                var atlasTexture = new AtlasTexture(
+                    sheet,
+                    UIBox2.FromDimensions(
+                        scaled.CurSheetX,
+                        scaled.CurSheetY,
+                        bitmap.Width,
+                        bitmap.Rows));
+
+                scaled.AtlasData.Add(glyph, atlasTexture);
+
+                scaled.CurSheetMaxY = Math.Max(scaled.CurSheetMaxY, scaled.CurSheetY + bitmap.Rows);
+                scaled.CurSheetX += bitmap.Width;
+            }
+            else
+            {
+                scaled.AtlasData.Add(glyph, null);
+            }
+
+            scaled.MetricsMap.Add(glyph, metrics);
+
+            OwnedTexture GenSheet()
+            {
+                var sheet = _clyde.CreateBlankTexture<A8>((SheetWidth, SheetHeight),
+                    $"font-{face.FamilyName}-{instance.Size}-{(uint) (BaseFontDPI * scale)}-sheet{scaled.AtlasTextures.Count}");
+                scaled.AtlasTextures.Add(sheet);
+                return sheet;
             }
         }
 
@@ -226,46 +223,6 @@ namespace Robust.Client.Graphics
             return bitmapImage;
         }
 
-        private Dictionary<char, uint> _generateGlyphMap(Face face)
-        {
-            var map = new Dictionary<char, uint>();
-
-            // TODO: Render more than extended ASCII, Cyrillic and Greek. somehow.
-            // Does it make sense to just render every glyph in the font?
-
-            // Render all the extended ASCII characters.
-            // Yeah I know "extended ASCII" isn't a real thing get off my back.
-            for (var i = 32u; i <= 255; i++)
-            {
-                _addGlyph(i, face, map);
-            }
-
-            // Render basic cyrillic.
-            for (var i = 0x0410u; i <= 0x044F; i++)
-            {
-                _addGlyph(i, face, map);
-            }
-
-            // Render greek.
-            for (var i = 0x03B1u; i <= 0x03C9; i++)
-            {
-                _addGlyph(i, face, map);
-            }
-
-            return map;
-        }
-
-        private static void _addGlyph(uint codePoint, Face face, Dictionary<char, uint> map)
-        {
-            var glyphIndex = face.GetCharIndex(codePoint);
-            if (glyphIndex == 0)
-            {
-                return;
-            }
-
-            map.Add((char) codePoint, glyphIndex);
-        }
-
         private class FontFaceHandle : IFontFaceHandle
         {
             public Face Face { get; }
@@ -282,78 +239,84 @@ namespace Robust.Client.Graphics
             public FontFaceHandle FaceHandle { get; }
             public int Size { get; }
             private readonly Dictionary<float, ScaledFontData> _scaledData = new();
-            public readonly IReadOnlyDictionary<char, uint> GlyphMap;
             private readonly FontManager _fontManager;
+            public readonly Dictionary<Rune, uint> GlyphMap;
 
-            public FontInstanceHandle(FontManager fontManager, int size, IReadOnlyDictionary<char, uint> glyphMap,
-                FontFaceHandle faceHandle)
+            public FontInstanceHandle(FontManager fontManager, int size, FontFaceHandle faceHandle)
             {
+                GlyphMap = new Dictionary<Rune, uint>();
                 _fontManager = fontManager;
                 Size = size;
-                GlyphMap = glyphMap;
                 FaceHandle = faceHandle;
             }
 
-            public Texture? GetCharTexture(char chr, float scale)
+            public Texture? GetCharTexture(Rune codePoint, float scale)
             {
-                var glyph = _getGlyph(chr);
+                var glyph = GetGlyph(codePoint);
                 if (glyph == 0)
-                {
                     return null;
-                }
 
-                var scaled = _getScaleDatum(scale);
-                scaled.Atlas.AtlasData.TryGetValue(glyph, out var texture);
+                var scaled = GetScaleDatum(scale);
+                _fontManager.CacheGlyph(this, scaled, scale, glyph);
+
+                scaled.AtlasData.TryGetValue(glyph, out var texture);
                 return texture;
             }
 
-            public CharMetrics? GetCharMetrics(char chr, float scale)
+            public CharMetrics? GetCharMetrics(Rune codePoint, float scale)
             {
-                var glyph = _getGlyph(chr);
+                var glyph = GetGlyph(codePoint);
                 if (glyph == 0)
                 {
                     return null;
                 }
 
-                var scaled = _getScaleDatum(scale);
+                var scaled = GetScaleDatum(scale);
+                _fontManager.CacheGlyph(this, scaled, scale, glyph);
+
                 return scaled.MetricsMap[glyph];
             }
 
             public int GetAscent(float scale)
             {
-                var scaled = _getScaleDatum(scale);
+                var scaled = GetScaleDatum(scale);
                 return scaled.Ascent;
             }
 
             public int GetDescent(float scale)
             {
-                var scaled = _getScaleDatum(scale);
+                var scaled = GetScaleDatum(scale);
                 return scaled.Descent;
             }
 
             public int GetHeight(float scale)
             {
-                var scaled = _getScaleDatum(scale);
+                var scaled = GetScaleDatum(scale);
                 return scaled.Height;
             }
 
             public int GetLineHeight(float scale)
             {
-                var scaled = _getScaleDatum(scale);
+                var scaled = GetScaleDatum(scale);
                 return scaled.LineHeight;
             }
 
-            private uint _getGlyph(char chr)
+            private uint GetGlyph(Rune chr)
             {
                 if (GlyphMap.TryGetValue(chr, out var glyph))
                 {
                     return glyph;
                 }
 
-                return 0;
+                // Check FreeType to see if it exists.
+                var index = FaceHandle.Face.GetCharIndex((uint) chr.Value);
+
+                GlyphMap.Add(chr, index);
+
+                return index;
             }
 
-            private ScaledFontData _getScaleDatum(float scale)
+            private ScaledFontData GetScaleDatum(float scale)
             {
                 if (_scaledData.TryGetValue(scale, out var datum))
                 {
@@ -368,37 +331,25 @@ namespace Robust.Client.Graphics
 
         private class ScaledFontData
         {
-            public ScaledFontData(IReadOnlyDictionary<uint, CharMetrics> metricsMap, int ascent, int descent,
-                int height, int lineHeight, FontTextureAtlas atlas)
+            public ScaledFontData(int ascent, int descent, int height, int lineHeight)
             {
-                MetricsMap = metricsMap;
                 Ascent = ascent;
                 Descent = descent;
                 Height = height;
                 LineHeight = lineHeight;
-                Atlas = atlas;
             }
 
-            public IReadOnlyDictionary<uint, CharMetrics> MetricsMap { get; }
-            public int Ascent { get; }
-            public int Descent { get; }
-            public int Height { get; }
-            public int LineHeight { get; }
-            public FontTextureAtlas Atlas { get; }
-        }
+            public readonly List<OwnedTexture> AtlasTextures = new();
+            public readonly Dictionary<uint, AtlasTexture?> AtlasData = new();
+            public readonly Dictionary<uint, CharMetrics> MetricsMap = new();
+            public readonly int Ascent;
+            public readonly int Descent;
+            public readonly int Height;
+            public readonly int LineHeight;
 
-        private class FontTextureAtlas
-        {
-            public FontTextureAtlas(Texture mainTexture, Dictionary<uint, AtlasTexture> atlasData)
-            {
-                MainTexture = mainTexture;
-                AtlasData = atlasData;
-            }
-
-            public Texture MainTexture { get; }
-
-            // Maps glyph index to atlas.
-            public Dictionary<uint, AtlasTexture> AtlasData { get; }
+            public int CurSheetX;
+            public int CurSheetY;
+            public int CurSheetMaxY;
         }
     }
 }

Robust.Client/Graphics/OwnedTexture.cs

@@ -1,5 +1,7 @@
 using System;
 using Robust.Shared.Maths;
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.PixelFormats;
 
 namespace Robust.Client.Graphics
 {
@@ -12,21 +14,42 @@ namespace Robust.Client.Graphics
         {
         }
 
+        /// <summary>
+        ///     Modifies a sub area of the texture with new data.
+        /// </summary>
+        /// <param name="topLeft">The top left corner of the area to modify.</param>
+        /// <param name="sourceImage">The image from which to copy pixel data.</param>
+        /// <param name="sourceRegion">The rectangle inside <paramref name="sourceImage"/> from which to copy.</param>
+        /// <typeparam name="T">
+        /// The type of pixels being used.
+        /// This must match the type used when creating the texture.
+        /// </typeparam>
+        public abstract void SetSubImage<T>(Vector2i topLeft, Image<T> sourceImage, in UIBox2i sourceRegion)
+            where T : unmanaged, IPixel<T>;
+
+        /// <summary>
+        ///     Modifies a sub area of the texture with new data.
+        /// </summary>
+        /// <param name="topLeft">The top left corner of the area to modify.</param>
+        /// <param name="sourceImage">The image to paste onto the texture.</param>
+        /// <typeparam name="T">
+        /// The type of pixels being used.
+        /// This must match the type used when creating the texture.
+        /// </typeparam>
+        public void SetSubImage<T>(Vector2i topLeft, Image<T> sourceImage)
+            where T : unmanaged, IPixel<T>
+        {
+            SetSubImage(topLeft, sourceImage, UIBox2i.FromDimensions(0, 0, sourceImage.Width, sourceImage.Height));
+        }
+
         public void Dispose()
         {
             Dispose(true);
             GC.SuppressFinalize(this);
         }
 
-        [Obsolete("Use Dispose() instead")]
-        public void Delete()
-        {
-            Dispose();
-        }
-
         protected virtual void Dispose(bool disposing)
         {
-
         }
 
         ~OwnedTexture()

Robust.Client/Graphics/RSI/RSISchema.json

@@ -31,7 +31,7 @@
                     }
                 }
             },
-            "required": ["name","directions"] //'delays' is marked as optional in the spec
+            "required": ["name"] //'delays' is marked as optional in the spec
         }
     },
     "properties": {

Robust.Client/Input/InputManager.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
@@ -134,7 +134,8 @@ namespace Robust.Client.Input
                     Priority = p.Priority,
                     Type = p.BindingType,
                     CanFocus = p.CanFocus,
-                    CanRepeat = p.CanRepeat
+                    CanRepeat = p.CanRepeat,
+                    AllowSubCombs = p.AllowSubCombs
                 }).ToArray();
 
             var leaveEmpty = _modifiedKeyFunctions
@@ -203,6 +204,7 @@ namespace Robust.Client.Input
 
             var bindsDown = new List<KeyBinding>();
             var hasCanFocus = false;
+            var hasAllowSubCombs = false;
 
             // bindings are ordered with larger combos before single key bindings so combos have priority.
             foreach (var binding in _bindings)
@@ -221,12 +223,22 @@ namespace Robust.Client.Input
                         matchedCombo = binding.PackedKeyCombo;
 
                         bindsDown.Add(binding);
+
                         hasCanFocus |= binding.CanFocus;
+                        hasAllowSubCombs |= binding.AllowSubCombs;
+
                     }
                     else if (PackedIsSubPattern(matchedCombo, binding.PackedKeyCombo))
                     {
-                        // kill any lower level matches
-                        UpBind(binding);
+                        if (hasAllowSubCombs)
+                        {
+                            bindsDown.Add(binding);
+                        }
+                        else
+                        {
+                            // kill any lower level matches
+                            UpBind(binding);
+                        }
                     }
                 }
             }
@@ -378,8 +390,8 @@ namespace Robust.Client.Input
         {
             for (var i = 0; i < 32; i += 8)
             {
-                var key = (Key) (subPackedCombo.Packed >> i);
-                if (!PackedContainsKey(packedCombo, key))
+                var key = (Key) ((subPackedCombo.Packed >> i) & 0b_1111_1111);
+                if (key != Key.Unknown && !PackedContainsKey(packedCombo, key))
                 {
                     return false;
                 }
@@ -453,7 +465,7 @@ namespace Robust.Client.Input
         public IKeyBinding RegisterBinding(BoundKeyFunction function, KeyBindingType bindingType,
             Key baseKey, Key? mod1, Key? mod2, Key? mod3)
         {
-            var binding = new KeyBinding(this, function, bindingType, baseKey, false, false,
+            var binding = new KeyBinding(this, function, bindingType, baseKey, false, false, false,
                 0, mod1 ?? Key.Unknown, mod2 ?? Key.Unknown, mod3 ?? Key.Unknown);
 
             RegisterBinding(binding);
@@ -464,7 +476,7 @@ namespace Robust.Client.Input
         public IKeyBinding RegisterBinding(in KeyBindingRegistration reg, bool markModified = true)
         {
             var binding = new KeyBinding(this, reg.Function, reg.Type, reg.BaseKey, reg.CanFocus, reg.CanRepeat,
-                reg.Priority, reg.Mod1, reg.Mod2, reg.Mod3);
+                reg.AllowSubCombs, reg.Priority, reg.Mod1, reg.Mod2, reg.Mod3);
 
             RegisterBinding(binding, markModified);
 
@@ -619,12 +631,18 @@ namespace Robust.Client.Input
             [ViewVariables]
             public bool CanRepeat { get; internal set; }
 
+            /// <summary>
+            ///     Whether the Bound Key Combination allows Sub Combinations of it to trigger.
+            /// </summary>
+            [ViewVariables]
+            public bool AllowSubCombs { get; internal set; }
+
             [ViewVariables] public int Priority { get; internal set; }
 
             public KeyBinding(InputManager inputManager, BoundKeyFunction function,
                 KeyBindingType bindingType,
                 Key baseKey,
-                bool canFocus, bool canRepeat, int priority, Key mod1 = Key.Unknown,
+                bool canFocus, bool canRepeat, bool allowSubCombs, int priority, Key mod1 = Key.Unknown,
                 Key mod2 = Key.Unknown,
                 Key mod3 = Key.Unknown)
             {
@@ -632,6 +650,7 @@ namespace Robust.Client.Input
                 BindingType = bindingType;
                 CanFocus = canFocus;
                 CanRepeat = canRepeat;
+                AllowSubCombs = allowSubCombs;
                 Priority = priority;
                 _inputManager = inputManager;
 

Robust.Client/Interfaces/Graphics/IClyde.cs

@@ -34,6 +34,29 @@ namespace Robust.Client.Interfaces.Graphics
         Texture LoadTextureFromImage<T>(Image<T> image, string? name = null,
             TextureLoadParameters? loadParams = null) where T : unmanaged, IPixel<T>;
 
+        /// <summary>
+        ///     Creates a blank texture of the specified parameters.
+        ///     This texture can later be modified using <see cref="OwnedTexture.SetSubImage{T}"/>
+        /// </summary>
+        /// <param name="size">The size of the new texture, in pixels.</param>
+        /// <param name="name">A name for the texture that can show up in debugging tools like renderdoc.</param>
+        /// <param name="loadParams">
+        ///     Load parameters for the texture describing stuff such as sample mode.
+        /// </param>
+        /// <typeparam name="T">
+        ///     The type of pixels to "store" in the texture.
+        ///     This is the same type you should pass to <see cref="OwnedTexture.SetSubImage{T}"/>,
+        ///     and also determines how the texture is stored internally.
+        /// </typeparam>
+        /// <returns>
+        ///     An owned, mutable texture object.
+        /// </returns>
+        OwnedTexture CreateBlankTexture<T>(
+            Vector2i size,
+            string? name = null,
+            in TextureLoadParameters? loadParams = null)
+            where T : unmanaged, IPixel<T>;
+
         IRenderTexture CreateRenderTarget(Vector2i size, RenderTargetFormatParameters format,
             TextureSampleParameters? sampleParameters = null, string? name = null);
 

Robust.Client/Interfaces/Graphics/IFontManager.cs

@@ -1,4 +1,5 @@
 using System.IO;
+using System.Text;
 using Robust.Client.Graphics;
 
 namespace Robust.Client.Interfaces.Graphics
@@ -22,8 +23,13 @@ namespace Robust.Client.Interfaces.Graphics
 
     internal interface IFontInstanceHandle
     {
-        Texture? GetCharTexture(char chr, float scale);
-        CharMetrics? GetCharMetrics(char chr, float scale);
+
+
+        Texture? GetCharTexture(Rune codePoint, float scale);
+        Texture? GetCharTexture(char chr, float scale) => GetCharTexture((Rune) chr, scale);
+        CharMetrics? GetCharMetrics(Rune codePoint, float scale);
+        CharMetrics? GetCharMetrics(char chr, float scale) => GetCharMetrics((Rune) chr, scale);
+
         int GetAscent(float scale);
         int GetDescent(float scale);
         int GetHeight(float scale);

Robust.Client/Interfaces/Input/IKeyBinding.cs

@@ -16,6 +16,7 @@ namespace Robust.Client.Interfaces.Input
 
         bool CanFocus { get; }
         bool CanRepeat { get; }
+        bool AllowSubCombs { get; }
         int Priority { get; }
 
         /// <summary>

Robust.Client/Interfaces/Input/KeyBindingRegistration.cs

@@ -1,4 +1,4 @@
-using Robust.Client.Input;
+using Robust.Client.Input;
 using Robust.Shared.Input;
 using Robust.Shared.Interfaces.Serialization;
 using Robust.Shared.Serialization;
@@ -16,6 +16,7 @@ namespace Robust.Client.Interfaces.Input
         public int Priority;
         public bool CanFocus;
         public bool CanRepeat;
+        public bool AllowSubCombs;
 
         public void ExposeData(ObjectSerializer serializer)
         {
@@ -28,6 +29,7 @@ namespace Robust.Client.Interfaces.Input
             serializer.DataField(ref Priority, "priority", 0);
             serializer.DataField(ref CanFocus, "canFocus", false);
             serializer.DataField(ref CanRepeat, "canRepeat", false);
+            serializer.DataField(ref AllowSubCombs, "allowSubCombs", false);
         }
     }
 }

Robust.Client/Interfaces/UserInterface/IUserInterfaceManager.cs

@@ -21,8 +21,22 @@ namespace Robust.Client.Interfaces.UserInterface
         /// </summary>
         Stylesheet? Stylesheet { get; set; }
 
+        /// <summary>
+        /// A control can have "keyboard focus" separate from ControlFocused, obtained when calling
+        /// Control.GrabKeyboardFocus. Corresponding events in Control are KeyboardFocusEntered/Exited
+        /// </summary>
         Control? KeyboardFocused { get; }
 
+        /// <summary>
+        /// A control gets "ControlFocused" when a mouse button (or any KeyBinding which has CanFocus = true) is
+        /// pressed down on the control. While it is focused, it will receive mouse hover events and the corresponding
+        /// keyup event if it still has focus when that occurs (it will NOT receive the keyup if focus has
+        /// been taken by another control). Focus is removed when a different control takes focus
+        /// (such as by pressing a different mouse button down over a different control) or when the keyup event
+        /// happens. When focus is lost on a control, it always fires Control.ControlFocusExited.
+        /// </summary>
+        Control? ControlFocused { get; }
+
         LayoutContainer StateRoot { get; }
 
         LayoutContainer WindowRoot { get; }

Robust.Client/Placement/PlacementManager.cs

@@ -98,9 +98,9 @@ namespace Robust.Client.Placement
         public bool Eraser { get; private set; }
 
         /// <summary>
-        /// The texture we use to show from our placement manager to represent the entity to place
+        ///     The texture we use to show from our placement manager to represent the entity to place
         /// </summary>
-        public IDirectionalTextureProvider? CurrentBaseSprite { get; set; }
+        public List<IDirectionalTextureProvider>? CurrentTextures { get; set; }
 
         /// <summary>
         /// Which of the placement orientations we are trying to place with
@@ -311,7 +311,7 @@ namespace Robust.Client.Placement
         {
             PlacementChanged?.Invoke(this, EventArgs.Empty);
             Hijack = null;
-            CurrentBaseSprite = null;
+            CurrentTextures = null;
             CurrentPrototype = null;
             CurrentPermission = null;
             CurrentMode = null;
@@ -555,7 +555,7 @@ namespace Robust.Client.Placement
         {
             var prototype = _prototypeManager.Index<EntityPrototype>(templateName);
 
-            CurrentBaseSprite = SpriteComponent.GetPrototypeIcon(prototype, ResourceCache);
+            CurrentTextures = SpriteComponent.GetPrototypeTextures(prototype, ResourceCache).ToList();
             CurrentPrototype = prototype;
 
             IsActive = true;
@@ -563,8 +563,9 @@ namespace Robust.Client.Placement
 
         private void PreparePlacementTile()
         {
-            CurrentBaseSprite = ResourceCache
-                .GetResource<TextureResource>(new ResourcePath("/Textures/UserInterface/tilebuildoverlay.png")).Texture;
+            CurrentTextures = new List<IDirectionalTextureProvider>
+            {ResourceCache
+                .GetResource<TextureResource>(new ResourcePath("/Textures/UserInterface/tilebuildoverlay.png")).Texture};
 
             IsActive = true;
         }

Robust.Client/Placement/PlacementMode.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using Robust.Client.Graphics;
 using Robust.Client.Graphics.ClientEye;
 using Robust.Client.Graphics.Drawing;
@@ -28,9 +29,9 @@ namespace Robust.Client.Placement
         public EntityCoordinates MouseCoords { get; set; }
 
         /// <summary>
-        /// Texture resource to draw to represent the entity we are tryign to spawn
+        /// Texture resources to draw to represent the entity we are trying to spawn
         /// </summary>
-        public Texture? SpriteToDraw { get; set; }
+        public List<Texture>? TexturesToDraw { get; set; }
 
         /// <summary>
         /// Color set to the ghost entity when it has a valid spawn position
@@ -85,12 +86,15 @@ namespace Robust.Client.Placement
 
         public virtual void Render(DrawingHandleWorld handle)
         {
-            if (SpriteToDraw == null)
+            if (TexturesToDraw == null)
             {
                 SetSprite();
-                DebugTools.AssertNotNull(SpriteToDraw);
+                DebugTools.AssertNotNull(TexturesToDraw);
             }
 
+            if (TexturesToDraw == null || TexturesToDraw.Count == 0)
+                return;
+
             IEnumerable<EntityCoordinates> locationcollection;
             switch (pManager.PlacementType)
             {
@@ -108,13 +112,17 @@ namespace Robust.Client.Placement
                     break;
             }
 
-            var size = SpriteToDraw!.Size;
+            var size = TexturesToDraw[0].Size;
             foreach (var coordinate in locationcollection)
             {
                 var worldPos = coordinate.ToMapPos(pManager.EntityManager);
                 var pos = worldPos - (size/(float)EyeManager.PixelsPerMeter) / 2f;
                 var color = IsValidPosition(coordinate) ? ValidPlaceColor : InvalidPlaceColor;
-                handle.DrawTexture(SpriteToDraw, pos, color);
+
+                foreach (var texture in TexturesToDraw)
+                {
+                    handle.DrawTexture(texture, pos, color);
+                }
             }
         }
 
@@ -188,7 +196,10 @@ namespace Robust.Client.Placement
 
         public void SetSprite()
         {
-            SpriteToDraw = pManager.CurrentBaseSprite!.TextureFor(pManager.Direction);
+            if (pManager.CurrentTextures == null)
+                return;
+
+            TexturesToDraw = pManager.CurrentTextures.Select(o => o.TextureFor(pManager.Direction)).ToList();
         }
 
         /// <summary>

Robust.Client/ResourceManagement/ResourceTypes/FontResource.cs

@@ -13,12 +13,15 @@ namespace Robust.Client.ResourceManagement
 
         public override void Load(IResourceCache cache, ResourcePath path)
         {
-            if (!cache.ContentFileExists(path))
+            if (!cache.TryContentFileRead(path, out var stream))
             {
                 throw new FileNotFoundException("Content file does not exist for font");
             }
 
-            FontFaceHandle = IoCManager.Resolve<IFontManagerInternal>().Load(cache.ContentFileRead(path));
+            using (stream)
+            {
+                FontFaceHandle = IoCManager.Resolve<IFontManagerInternal>().Load(stream);
+            }
         }
 
         public VectorFont MakeDefault()

Robust.Client/ResourceManagement/ResourceTypes/RSIResource.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Reflection;
-
 using Robust.Client.Graphics;
 using Robust.Client.Interfaces.ResourceManagement;
 using Robust.Client.Utility;
@@ -83,7 +82,12 @@ namespace Robust.Client.ResourceManagement
             {
                 // Load image from disk.
                 var texPath = path / (stateObject.StateId + ".png");
-                var image = Image.Load<Rgba32>(cache.ContentFileRead(texPath));
+                var stream = cache.ContentFileRead(texPath);
+                Image<Rgba32> image;
+                using (stream)
+                {
+                    image = Image.Load<Rgba32>(stream);
+                }
                 var sheetSize = new Vector2i(image.Width, image.Height);
 
                 if (sheetSize.X % frameSize.X != 0 || sheetSize.Y % frameSize.Y != 0)
@@ -341,15 +345,25 @@ namespace Robust.Client.ResourceManagement
             foreach (var stateObject in manifestJson["states"]!.Cast<JObject>())
             {
                 var stateName = stateObject["name"]!.ToObject<string>()!;
-                var dirValue = stateObject["directions"]!.ToObject<int>();
+                RSI.State.DirectionType directions;
+                int dirValue;
 
-                var directions = dirValue switch
+                if (stateObject.TryGetValue("directions", out var dirJToken))
                 {
-                    1 => RSI.State.DirectionType.Dir1,
-                    4 => RSI.State.DirectionType.Dir4,
-                    8 => RSI.State.DirectionType.Dir8,
-                    _ => throw new RSILoadException($"Invalid direction: {dirValue}")
-                };
+                    dirValue= dirJToken.ToObject<int>();
+                    directions = dirValue switch
+                    {
+                        1 => RSI.State.DirectionType.Dir1,
+                        4 => RSI.State.DirectionType.Dir4,
+                        8 => RSI.State.DirectionType.Dir8,
+                        _ => throw new RSILoadException($"Invalid direction: {dirValue} expected 1, 4 or 8")
+                    };
+                }
+                else
+                {
+                    dirValue = 1;
+                    directions = RSI.State.DirectionType.Dir1;
+                }
 
                 // We can ignore selectors and flags for now,
                 // because they're not used yet!

Robust.Client/ResourceManagement/ResourceTypes/TextureResource.cs

@@ -26,20 +26,23 @@ namespace Robust.Client.ResourceManagement
                 throw new FileNotFoundException("Content file does not exist for texture");
             }
 
-            // Primarily for tracking down iCCP sRGB errors in the image files.
-            Logger.DebugS("res.tex", $"Loading texture {path}.");
-
-            var loadParameters = _tryLoadTextureParameters(cache, path) ?? TextureLoadParameters.Default;
-
-            var manager = IoCManager.Resolve<IClyde>();
-
-            using var image = Image.Load<Rgba32>(stream);
-
-            Texture = manager.LoadTextureFromImage(image, path.ToString(), loadParameters);
-
-            if (cache is IResourceCacheInternal cacheInternal)
+            using (stream)
             {
-                cacheInternal.TextureLoaded(new TextureLoadedEventArgs(path, image, this));
+                // Primarily for tracking down iCCP sRGB errors in the image files.
+                Logger.DebugS("res.tex", $"Loading texture {path}.");
+
+                var loadParameters = _tryLoadTextureParameters(cache, path) ?? TextureLoadParameters.Default;
+
+                var manager = IoCManager.Resolve<IClyde>();
+
+                using var image = Image.Load<Rgba32>(stream);
+
+                Texture = manager.LoadTextureFromImage(image, path.ToString(), loadParameters);
+
+                if (cache is IResourceCacheInternal cacheInternal)
+                {
+                    cacheInternal.TextureLoaded(new TextureLoadedEventArgs(path, image, this));
+                }
             }
         }
 
@@ -48,21 +51,25 @@ namespace Robust.Client.ResourceManagement
             var metaPath = path.WithName(path.Filename + ".yml");
             if (cache.TryContentFileRead(metaPath, out var stream))
             {
-                YamlDocument yamlData;
-                using (var reader = new StreamReader(stream, EncodingHelpers.UTF8))
+                using (stream)
                 {
-                    var yamlStream = new YamlStream();
-                    yamlStream.Load(reader);
-                    if (yamlStream.Documents.Count == 0)
+                    YamlDocument yamlData;
+                    using (var reader = new StreamReader(stream, EncodingHelpers.UTF8))
                     {
-                        return null;
+                        var yamlStream = new YamlStream();
+                        yamlStream.Load(reader);
+                        if (yamlStream.Documents.Count == 0)
+                        {
+                            return null;
+                        }
+
+                        yamlData = yamlStream.Documents[0];
                     }
 
-                    yamlData = yamlStream.Documents[0];
+                    return TextureLoadParameters.FromYaml((YamlMappingNode) yamlData.RootNode);
                 }
-
-                return TextureLoadParameters.FromYaml((YamlMappingNode)yamlData.RootNode);
             }
+
             return null;
         }
 

Robust.Client/Robust.Client.csproj

@@ -45,4 +45,10 @@
 
     <EmbeddedResource Include="Graphics\Clyde\Shaders\*" />
   </ItemGroup>
+  <Import Project="..\MSBuild\Robust.Engine.targets" />
+  <PropertyGroup>
+    <RobustToolsPath>../Tools</RobustToolsPath>
+  </PropertyGroup>
+  <Target Name="RobustAfterBuild" AfterTargets="Build" />
+  <Import Project="..\MSBuild\XamlIL.targets" />
 </Project>

Robust.Client/UserInterface/Control.cs

@@ -6,6 +6,7 @@ using JetBrains.Annotations;
 using Robust.Client.Graphics.Drawing;
 using Robust.Client.Interfaces.Graphics;
 using Robust.Client.Interfaces.UserInterface;
+using Robust.Client.UserInterface.XAML;
 using Robust.Shared.Animations;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
@@ -49,6 +50,45 @@ namespace Robust.Client.UserInterface
         [ViewVariables]
         public Control? Parent { get; private set; }
 
+        public NameScope? NameScope;
+
+        //public void AttachNameScope(Dictionary<string, Control> nameScope)
+        //{
+        //    _nameScope = nameScope;
+        //}
+
+        public NameScope? FindNameScope()
+        {
+            foreach (var control in this.GetSelfAndLogicalAncestors())
+            {
+                if (control.NameScope != null) return control.NameScope;
+            }
+
+            return null;
+        }
+
+        public T FindControl<T>(string name) where T : Control
+        {
+            var nameScope = FindNameScope();
+            if (nameScope == null)
+            {
+                throw new ArgumentException("No Namespace found for Control");
+            }
+
+            var value = nameScope.Find(name);
+            if (value == null)
+            {
+                throw new ArgumentException($"No Control with the name {name} found");
+            }
+
+            if (value is not T ret)
+            {
+                throw new ArgumentException($"Control with name {name} had invalid type {value.GetType()}");
+            }
+
+            return ret;
+        }
+
         internal IUserInterfaceManagerInternal UserInterfaceManagerInternal { get; }
 
         /// <summary>
@@ -62,6 +102,9 @@ namespace Robust.Client.UserInterface
         [ViewVariables]
         public OrderedChildCollection Children { get; }
 
+        [Content]
+        public virtual ICollection<Control> XamlChildren { get; protected set; }
+
         [ViewVariables] public int ChildCount => _orderedChildren.Count;
 
         /// <summary>
@@ -394,6 +437,7 @@ namespace Robust.Client.UserInterface
             UserInterfaceManagerInternal = IoCManager.Resolve<IUserInterfaceManagerInternal>();
             StyleClasses = new StyleClassCollection(this);
             Children = new OrderedChildCollection(this);
+            XamlChildren = Children;
         }
 
         /// <summary>
@@ -477,7 +521,7 @@ namespace Robust.Client.UserInterface
         {
             DebugTools.Assert(!Disposed, "Control has been disposed.");
 
-            foreach (var child in Children.ToList())
+            foreach (var child in Children.ToArray())
             {
                 RemoveChild(child);
             }
@@ -713,14 +757,32 @@ namespace Robust.Client.UserInterface
         /// <summary>
         ///     Called when this control receives keyboard focus.
         /// </summary>
-        protected internal virtual void FocusEntered()
+        protected internal virtual void KeyboardFocusEntered()
         {
         }
 
         /// <summary>
-        ///     Called when this control loses keyboard focus.
+        ///     Called when this control loses keyboard focus (corresponds to UserInterfaceManager.KeyboardFocused).
         /// </summary>
-        protected internal virtual void FocusExited()
+        protected internal virtual void KeyboardFocusExited()
+        {
+        }
+
+        /// <summary>
+        ///     Fired when a control loses control focus for any reason. See <see cref="IUserInterfaceManager.ControlFocused"/>.
+        /// </summary>
+        /// <remarks>
+        ///     Controls which have some sort of drag / drop behavior should usually implement this method (typically by cancelling the drag drop).
+        ///     Otherwise, if a user clicks down LMB over one control to initiate a drag, then clicks RMB down
+        ///     over a different control while still holding down LMB, the control being dragged will now lose focus
+        ///     and will no longer receive the keyup for the LMB, thus won't cancel the drag.
+        ///     This should also be considered for controls which have any special KeyBindUp behavior - consider
+        ///     what would happen if the control lost focus and never received the KeyBindUp.
+        ///
+        ///     There is no corresponding ControlFocusEntered - if a control wants to handle that situation they should simply
+        ///     handle KeyBindDown as that's the only way a control would gain focus.
+        /// </remarks>
+        protected internal virtual void ControlFocusExited()
         {
         }
 

Robust.Client/UserInterface/Controls/ItemList.cs

@@ -433,7 +433,7 @@ namespace Robust.Client.UserInterface.Controls
                 if (item.Region == null)
                     continue;
 
-                if (!item.Region.Value.Contains(args.RelativePosition))
+                if (!item.Region.Value.Contains(args.RelativePixelPosition))
                     continue;
 
                 if (item.Selectable && !item.Disabled)

Robust.Client/UserInterface/Controls/LineEdit.cs

@@ -589,18 +589,18 @@ namespace Robust.Client.UserInterface.Controls
             return index;
         }
 
-        protected internal override void FocusEntered()
+        protected internal override void KeyboardFocusEntered()
         {
-            base.FocusEntered();
+            base.KeyboardFocusEntered();
 
             // Reset this so the cursor is always visible immediately after gaining focus..
             _resetCursorBlink();
             OnFocusEnter?.Invoke(new LineEditEventArgs(this, _text));
         }
 
-        protected internal override void FocusExited()
+        protected internal override void KeyboardFocusExited()
         {
-            base.FocusExited();
+            base.KeyboardFocusExited();
             OnFocusExit?.Invoke(new LineEditEventArgs(this, _text));
         }
 

Robust.Client/UserInterface/Controls/RadioOptions.cs

@@ -0,0 +1,264 @@
+using Robust.Client.Graphics;
+using System;
+using System.Linq;
+using System.Collections.Generic;
+using static Robust.Client.UserInterface.Controls.BaseButton;
+
+namespace Robust.Client.UserInterface.Controls
+{
+    public enum RadioOptionsLayout { Horizontal, Vertical }
+
+    public class RadioOptions<T> : Control
+    {
+        private int internalIdCount = 0;
+
+        private readonly List<RadioOptionButtonData<T>> _buttonDataList = new();
+        //private readonly Dictionary<int, int> _idMap = new();
+        private ButtonGroup _buttonGroup = new();
+        private Container _container;
+
+        public string ButtonStyle = string.Empty;
+        public string FirstButtonStyle = string.Empty;
+        public string LastButtonStyle = string.Empty;
+
+        public int ItemCount => _buttonDataList.Count;
+
+        /// <summary>
+        /// Called whenever you select a button.
+        ///
+        /// Note: You should add optionButtons.Select(args.Id); if you want to actually select the button.
+        /// </summary>
+        public event Action<RadioOptionItemSelectedEventArgs<T>>? OnItemSelected;
+
+        public RadioOptions(RadioOptionsLayout layout)
+        {
+            switch (layout)
+            {
+                case RadioOptionsLayout.Vertical:
+                    _container = new VBoxContainer();
+                    break;
+                case RadioOptionsLayout.Horizontal:
+                default:
+                    _container = new HBoxContainer();
+                    break;
+            }
+
+            this.AddChild(_container);
+        }
+
+        public int AddItem(string label, T value, Action<RadioOptionItemSelectedEventArgs<T>>? itemSelectedAction = null)
+        {
+            var button = new Button
+            {
+                Text = label,
+                Group = _buttonGroup
+            };
+
+            button.OnPressed += ButtonOnPressed;
+
+            var data = new RadioOptionButtonData<T>(label, value, button)
+            {
+                Id = internalIdCount++
+            };
+
+            if (itemSelectedAction != null)
+            {
+                data.OnItemSelected += itemSelectedAction;
+            }
+
+            _buttonDataList.Add(data);
+            _container.AddChild(button);
+            UpdateFirstAndLastButtonStyle();
+
+            if (_buttonDataList.Count == 1)
+            {
+                Select(data.Id);
+            }
+            return data.Id;
+        }
+
+
+        /// <summary>
+        /// This is triggered when the button is pressed via the UI
+        /// </summary>
+        /// <param name="obj"></param>
+        private void ButtonOnPressed(ButtonEventArgs obj)
+        {
+            var buttonData = _buttonDataList.FirstOrDefault(bd => bd.Button == obj.Button);
+            if (buttonData != null)
+            {
+                InvokeItemSelected(new RadioOptionItemSelectedEventArgs<T>(buttonData.Id, this));
+                return;
+            }
+            // Not reachable.
+            throw new InvalidOperationException();
+        }
+
+        public void Clear()
+        {
+            foreach (var buttonDatum in _buttonDataList)
+            {
+                buttonDatum.Button.OnPressed -= ButtonOnPressed;
+            }
+            _buttonDataList.Clear();
+            _container.Children.Clear();
+            SelectedId = 0;
+        }
+
+        public object? GetItemMetadata(int idx)
+        {
+            return _buttonDataList.FirstOrDefault(bd => bd.Id == idx)?.Metadata;
+        }
+
+        public int SelectedId { get; private set; }
+        public RadioOptionButtonData<T> SelectedButtonData => _buttonDataList.First(bd => bd.Id == SelectedId);
+        public Button SelectedButton => SelectedButtonData.Button;
+        public string SelectedText => SelectedButtonData.Text;
+        public T SelectedValue => SelectedButtonData.Value;
+
+        /// <summary>
+        /// Always will return true if itemId is not found.
+        /// </summary>
+        /// <param name="idx"></param>
+        /// <returns></returns>
+        public bool IsItemDisabled(int idx)
+        {
+            return _buttonDataList.FirstOrDefault(bd => bd.Id == idx)?.Disabled ?? true;
+        }
+
+        public void RemoveItem(int idx)
+        {
+
+            var data = _buttonDataList.FirstOrDefault(bd => bd.Id == idx);
+            if (data!= null)
+            {
+                data.Button.OnPressed -= ButtonOnPressed;
+                _container.RemoveChild(data.Button);
+
+                var buttonData = _buttonDataList.FirstOrDefault(bd => bd.Id == idx);
+                if (buttonData != null)
+                    _buttonDataList.Remove(buttonData);
+
+                UpdateFirstAndLastButtonStyle();
+            }
+        }
+
+        public void Select(int idx)
+        {
+            var data = _buttonDataList.FirstOrDefault(bd => bd.Id == idx);
+            if (data != null)
+            {
+                SelectedId = data.Id;
+                data.Button.Pressed = true;
+                return;
+            }
+            // Not found.
+        }
+
+        public void SelectByValue(T value)
+        {
+            var data = _buttonDataList.FirstOrDefault(bd => EqualityComparer<T>.Default.Equals(bd.Value, value));
+            if (data != null)
+            {
+                Select(data.Id);
+            }
+        }
+
+        public void InvokeItemSelected(RadioOptionItemSelectedEventArgs<T> args)
+        {
+            var buttonData = _buttonDataList.FirstOrDefault(bd => bd.Id == args.Id);
+            if (buttonData == null) return;
+
+            if (buttonData.HasOnItemSelectedEvent)
+                buttonData.InvokeItemSelected(args);
+            else
+                OnItemSelected?.Invoke(args);
+        }
+
+        public void UpdateFirstAndLastButtonStyle()
+        {
+            for (int i = 0; i < _buttonDataList.Count; i++)
+            {
+                var buttonData = _buttonDataList[i];
+                if (buttonData.Button == null) continue;
+
+                buttonData.Button.StyleClasses.Remove(ButtonStyle);
+                buttonData.Button.StyleClasses.Remove(LastButtonStyle);
+                buttonData.Button.StyleClasses.Remove(FirstButtonStyle);
+
+                if (i == 0)
+                    buttonData.Button.StyleClasses.Add(FirstButtonStyle);
+                else if (i == _buttonDataList.Count - 1)
+                    buttonData.Button.StyleClasses.Add(LastButtonStyle);
+                else
+                    buttonData.Button.StyleClasses.Add(ButtonStyle);
+            }
+        }
+
+        public void SetItemDisabled(int idx, bool disabled)
+        {
+            var data = _buttonDataList.FirstOrDefault(bd => bd.Id == idx);
+            if (data != null)
+            {
+                data.Disabled = disabled;
+                data.Button.Disabled = disabled;
+            }
+        }
+
+        public void SetItemMetadata(int idx, object metadata)
+        {
+            var buttonData = _buttonDataList.FirstOrDefault(bd => bd.Id == idx);
+            if (buttonData != null)
+                buttonData.Metadata = metadata;
+        }
+
+        public void SetItemText(int idx, string text)
+        {
+            var data = _buttonDataList.FirstOrDefault(bd => bd.Id == idx);
+            if (data != null)
+            {
+                data.Text = text;
+                data.Button.Text = text;
+            }
+        }
+    }
+    public class RadioOptionItemSelectedEventArgs<T> : EventArgs
+    {
+        public RadioOptions<T> Button { get; }
+
+        /// <summary>
+        ///     The ID of the item that has been selected.
+        /// </summary>
+        public int Id { get; }
+
+        public RadioOptionItemSelectedEventArgs(int id, RadioOptions<T> button)
+        {
+            Id = id;
+            Button = button;
+        }
+    }
+
+    public sealed class RadioOptionButtonData<T>
+    {
+        public int Id;
+        public string Text;
+        public T Value;
+        public bool Disabled;
+        public object? Metadata;
+
+        public Button Button;
+
+        public RadioOptionButtonData(string text, T value, Button button)
+        {
+            Text = text;
+            this.Button = button;
+            Value = value;
+        }
+        public event Action<RadioOptionItemSelectedEventArgs<T>>? OnItemSelected;
+        public bool HasOnItemSelectedEvent => OnItemSelected != null;
+        public void InvokeItemSelected(RadioOptionItemSelectedEventArgs<T> args)
+        {
+            OnItemSelected?.Invoke(args);
+        }
+    }
+}

Robust.Client/UserInterface/CustomControls/DebugInputPanel.cs

@@ -31,6 +31,11 @@ namespace Robust.Client.UserInterface.CustomControls
         {
             base.FrameUpdate(args);
 
+            if (!VisibleInTree)
+            {
+                return;
+            }
+
             _label.Text = string.Join("\n", _inputManager.DownKeyFunctions);
         }
     }

Robust.Client/UserInterface/CustomControls/DebugNetPanel.cs

@@ -64,6 +64,11 @@ namespace Robust.Client.UserInterface.CustomControls
                 return;
             }
 
+            if (!VisibleInTree)
+            {
+                return;
+            }
+
             if (!NetManager.IsConnected)
             {
                 contents.Text = "Not connected to server.";

Robust.Client/UserInterface/CustomControls/SS14Window.xaml

@@ -0,0 +1,15 @@
+<cc:SS14Window xmlns:cc="clr-namespace:Robust.Client.UserInterface.CustomControls"
+                           xmlns:c="clr-namespace:Robust.Client.UserInterface.Controls">
+    <c:PanelContainer StyleClasses="windowPanel"/>
+    <c:VBoxContainer SeparationOverride="0">
+        <c:PanelContainer Name="WindowHeader" StyleClasses="windowHeader">
+            <c:HBoxContainer>
+                <c:MarginContainer MarginLeftOverride="5" SizeFlagsHorizontal="FillExpand">
+                    <c:Label Name="TitleLabel" StyleIdentifier="foo" ClipText="True" Text="Exemplary Window Title Here" VAlign="Center" StyleClasses="windowTitle"/>
+                </c:MarginContainer>
+                <c:TextureButton Name="CloseButton" StyleClasses="windowCloseButton" SizeFlagsVertical="ShrinkCenter"></c:TextureButton>
+            </c:HBoxContainer>
+        </c:PanelContainer>
+        <c:MarginContainer Name="ContentsContainer" MarginBottomOverride="10" MarginLeftOverride="10" MarginRightOverride="10" MarginTopOverride="10" RectClipContent="True" SizeFlagsVertical="FillExpand" />
+    </c:VBoxContainer>
+</cc:SS14Window>

Robust.Client/UserInterface/CustomControls/SS14Window.xaml.cs

@@ -1,12 +1,17 @@
-using System;
+using System.Collections;
+using System.Collections.Generic;
+using Robust.Client.AutoGenerated;
 using Robust.Client.UserInterface.Controls;
+using Robust.Client.UserInterface.XAML;
 using Robust.Shared.Maths;
 using Robust.Shared.Timing;
+using Robust.Shared.Utility;
 
 namespace Robust.Client.UserInterface.CustomControls
 {
+    [GenerateTypedNameReferences]
     // ReSharper disable once InconsistentNaming
-    public class SS14Window : BaseWindow
+    public partial class SS14Window : BaseWindow
     {
         public const string StyleClassWindowTitle = "windowTitle";
         public const string StyleClassWindowPanel = "windowPanel";
@@ -17,70 +22,19 @@ namespace Robust.Client.UserInterface.CustomControls
 
         public SS14Window()
         {
+            RobustXamlLoader.Load(this);
             MouseFilter = MouseFilterMode.Stop;
 
-            AddChild(new PanelContainer
-            {
-                StyleClasses = {StyleClassWindowPanel}
-            });
+            WindowHeader.CustomMinimumSize = (0, HEADER_SIZE_Y);
 
-            AddChild(new VBoxContainer
-            {
-                SeparationOverride = 0,
-                Children =
-                {
-                    new PanelContainer
-                    {
-                        StyleClasses = {StyleClassWindowHeader},
-                        CustomMinimumSize = (0, HEADER_SIZE_Y),
-                        Children =
-                        {
-                            new HBoxContainer
-                            {
-                                Children =
-                                {
-                                    new MarginContainer
-                                    {
-                                        MarginLeftOverride = 5,
-                                        SizeFlagsHorizontal = SizeFlags.FillExpand,
-                                        Children =
-                                        {
-                                            (TitleLabel = new Label
-                                            {
-                                                StyleIdentifier = "foo",
-                                                ClipText = true,
-                                                Text = "Exemplary Window Title Here",
-                                                VAlign = Label.VAlignMode.Center,
-                                                StyleClasses = {StyleClassWindowTitle}
-                                            })
-                                        }
-                                    },
-                                    (CloseButton = new TextureButton
-                                    {
-                                        StyleClasses = {StyleClassWindowCloseButton},
-                                        SizeFlagsVertical = SizeFlags.ShrinkCenter
-                                    })
-                                }
-                            }
-                        }
-                    },
-                    (Contents = new MarginContainer
-                    {
-                        MarginBottomOverride = 10,
-                        MarginLeftOverride = 10,
-                        MarginRightOverride = 10,
-                        MarginTopOverride = 10,
-                        RectClipContent = true,
-                        SizeFlagsVertical = SizeFlags.FillExpand
-                    })
-                }
-            });
+            Contents = ContentsContainer;
 
             CloseButton.OnPressed += CloseButtonPressed;
+            XamlChildren = new SS14ContentCollection(this);
         }
 
         public MarginContainer Contents { get; private set; }
-        private TextureButton CloseButton;
+        //private TextureButton CloseButton;
 
         private const int DRAG_MARGIN_SIZE = 7;
 
@@ -103,7 +57,7 @@ namespace Robust.Client.UserInterface.CustomControls
             }
         }
 
-        private Label TitleLabel;
+        //private Label TitleLabel;
 
         public string? Title
         {
@@ -177,5 +131,91 @@ namespace Robust.Client.UserInterface.CustomControls
 
             return mode;
         }
+
+        public class SS14ContentCollection : ICollection<Control>, IReadOnlyCollection<Control>
+        {
+            private readonly SS14Window Owner;
+
+            public SS14ContentCollection(SS14Window owner)
+            {
+                Owner = owner;
+            }
+
+            public Enumerator GetEnumerator()
+            {
+                return new(Owner);
+            }
+
+            IEnumerator<Control> IEnumerable<Control>.GetEnumerator() => GetEnumerator();
+            IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+            public void Add(Control item)
+            {
+                Owner.Contents.AddChild(item);
+            }
+
+            public void Clear()
+            {
+                Owner.Contents.RemoveAllChildren();
+            }
+
+            public bool Contains(Control item)
+            {
+                return item?.Parent == Owner.Contents;
+            }
+
+            public void CopyTo(Control[] array, int arrayIndex)
+            {
+                Owner.Contents.Children.CopyTo(array, arrayIndex);
+            }
+
+            public bool Remove(Control item)
+            {
+                if (item?.Parent != Owner.Contents)
+                {
+                    return false;
+                }
+
+                DebugTools.AssertNotNull(Owner?.Contents);
+                Owner!.Contents.RemoveChild(item);
+
+                return true;
+            }
+
+            int ICollection<Control>.Count => Owner.Contents.ChildCount;
+            int IReadOnlyCollection<Control>.Count => Owner.Contents.ChildCount;
+
+            public bool IsReadOnly => false;
+
+
+            public struct Enumerator : IEnumerator<Control>
+            {
+                private OrderedChildCollection.Enumerator _enumerator;
+
+                internal Enumerator(SS14Window ss14Window)
+                {
+                    _enumerator = ss14Window.Contents.Children.GetEnumerator();
+                }
+
+                public bool MoveNext()
+                {
+                    return _enumerator.MoveNext();
+                }
+
+                public void Reset()
+                {
+                    ((IEnumerator) _enumerator).Reset();
+                }
+
+                public Control Current => _enumerator.Current;
+
+                object IEnumerator.Current => Current;
+
+                public void Dispose()
+                {
+                    _enumerator.Dispose();
+                }
+            }
+        }
     }
 }

Robust.Client/UserInterface/FileDialogManager.cs

@@ -179,7 +179,17 @@ namespace Robust.Client.UserInterface
             return tcs.Task;
 #else
             // Luckily, GTK Linux and COM Windows are both happily threaded. Yay!
-            return Task.Run(action);
+            // * Actual attempts to have multiple file dialogs up at the same time, and the resulting crashes,
+            // have shown that at least for GTK+ (Linux), just because it can handle being on any thread doesn't mean it handle being on two at the same time.
+            // Testing system was Ubuntu 20.04.
+            // COM on Windows might handle this, but honestly, who exactly wants to risk it?
+            // In particular this could very well be an swnfd issue.
+            return Task.Run(() =>
+            {
+                lock (this) {
+                    return action();
+                }
+            });
 #endif
         }
 

Robust.Client/UserInterface/LogicalExtensions.cs

@@ -0,0 +1,17 @@
+using System.Collections.Generic;
+
+namespace Robust.Client.UserInterface
+{
+    public static class LogicalExtensions
+    {
+        public static IEnumerable<Control> GetSelfAndLogicalAncestors(this Control control)
+        {
+            Control? c = control;
+            while (c != null)
+            {
+                yield return c;
+                c = c.Parent;
+            }
+        }
+    }
+}

Robust.Client/UserInterface/RichTextEntry.cs

@@ -4,6 +4,7 @@ using JetBrains.Annotations;
 using Robust.Client.Graphics;
 using Robust.Client.Graphics.Drawing;
 using Robust.Client.UserInterface.Controls;
+using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 
@@ -172,8 +173,29 @@ namespace Robust.Client.UserInterface
             // This needs to happen because word wrapping doesn't get checked for the last word.
             if (posX > maxSizeX)
             {
-                DebugTools.Assert(wordStartBreakIndex.HasValue,
-                    "wordStartBreakIndex can only be null if the word begins at a new line, in which case this branch shouldn't be reached as the word would be split due to being longer than a single line.");
+                if (!wordStartBreakIndex.HasValue)
+                {
+                    Logger.Error(
+                        "Assert fail inside RichTextEntry.Update, " +
+                        "wordStartBreakIndex is null on method end w/ word wrap required. " +
+                        "Dumping relevant stuff. Send this to PJB.");
+                    Logger.Error($"Message: {Message}");
+                    Logger.Error($"maxSizeX: {maxSizeX}");
+                    Logger.Error($"maxUsedWidth: {maxUsedWidth}");
+                    Logger.Error($"breakIndexCounter: {breakIndexCounter}");
+                    Logger.Error("wordStartBreakIndex: null (duh)");
+                    Logger.Error($"wordSizePixels: {wordSizePixels}");
+                    Logger.Error($"posX: {posX}");
+                    Logger.Error($"lastChar: {lastChar}");
+                    Logger.Error($"forceSplitData: {forceSplitData}");
+                    Logger.Error($"LineBreaks: {string.Join(", ", LineBreaks)}");
+
+                    throw new Exception(
+                        "wordStartBreakIndex can only be null if the word begins at a new line," +
+                        "in which case this branch shouldn't be reached as" +
+                        "the word would be split due to being longer than a single line.");
+                }
+
                 LineBreaks.Add(wordStartBreakIndex!.Value.index);
                 Height += font.GetLineHeight(uiScale);
                 maxUsedWidth = Math.Max(maxUsedWidth, wordStartBreakIndex.Value.lineSize);

Robust.Client/UserInterface/UserInterfaceManager.cs

@@ -57,9 +57,7 @@ namespace Robust.Client.UserInterface
 
         public Control? KeyboardFocused { get; private set; }
 
-        // When a control receives a mouse down it must also receive a mouse up and mouse moves, always.
-        // So we keep track of which control is "focused" by the mouse.
-        private Control? _controlFocused;
+        public Control? ControlFocused { get; private set; }
 
         public LayoutContainer StateRoot { get; private set; } = default!;
         public PopupContainer ModalRoot { get; private set; } = default!;
@@ -244,7 +242,8 @@ namespace Robust.Client.UserInterface
                         RemoveModal(top);
                     else
                     {
-                        _controlFocused = top;
+                        ControlFocused?.ControlFocusExited();
+                        ControlFocused = top;
                         return false; // prevent anything besides the top modal control from receiving input
                     }
                 }
@@ -260,12 +259,12 @@ namespace Robust.Client.UserInterface
             {
                 return false;
             }
+            ControlFocused?.ControlFocusExited();
+            ControlFocused = control;
 
-            _controlFocused = control;
-
-            if (_controlFocused.CanKeyboardFocus && _controlFocused.KeyboardFocusOnClick)
+            if (ControlFocused.CanKeyboardFocus && ControlFocused.KeyboardFocusOnClick)
             {
-                _controlFocused.GrabKeyboardFocus();
+                ControlFocused.GrabKeyboardFocus();
             }
 
             return true;
@@ -273,7 +272,8 @@ namespace Robust.Client.UserInterface
 
         public void HandleCanFocusUp()
         {
-            _controlFocused = null;
+            ControlFocused?.ControlFocusExited();
+            ControlFocused = null;
         }
 
         public void KeyBindDown(BoundKeyEventArgs args)
@@ -290,7 +290,7 @@ namespace Robust.Client.UserInterface
                 return;
             }
 
-            var control = _controlFocused ?? KeyboardFocused ?? MouseGetControl(args.PointerLocation.Position);
+            var control = ControlFocused ?? KeyboardFocused ?? MouseGetControl(args.PointerLocation.Position);
 
             if (control == null)
             {
@@ -311,7 +311,7 @@ namespace Robust.Client.UserInterface
 
         public void KeyBindUp(BoundKeyEventArgs args)
         {
-            var control = _controlFocused ?? KeyboardFocused ?? MouseGetControl(args.PointerLocation.Position);
+            var control = ControlFocused ?? KeyboardFocused ?? MouseGetControl(args.PointerLocation.Position);
             if (control == null)
             {
                 return;
@@ -352,7 +352,7 @@ namespace Robust.Client.UserInterface
                 _needUpdateActiveCursor = true;
             }
 
-            var target = _controlFocused ?? newHovered;
+            var target = ControlFocused ?? newHovered;
             if (target != null)
             {
                 var guiArgs = new GUIMouseMoveEventArgs(mouseMoveEventArgs.Relative / UIScale,
@@ -368,7 +368,7 @@ namespace Robust.Client.UserInterface
         private void UpdateActiveCursor()
         {
             // Consider mouse input focus first so that dragging windows don't act up etc.
-            var cursorTarget = _controlFocused ?? CurrentlyHovered;
+            var cursorTarget = ControlFocused ?? CurrentlyHovered;
 
             if (cursorTarget == null)
             {
@@ -478,13 +478,13 @@ namespace Robust.Client.UserInterface
 
             KeyboardFocused = control;
 
-            KeyboardFocused.FocusEntered();
+            KeyboardFocused.KeyboardFocusEntered();
         }
 
         public void ReleaseKeyboardFocus()
         {
             var oldFocused = KeyboardFocused;
-            oldFocused?.FocusExited();
+            oldFocused?.KeyboardFocusExited();
             KeyboardFocused = null;
         }
 
@@ -528,10 +528,9 @@ namespace Robust.Client.UserInterface
                 _clearTooltip();
             }
 
-            if (control == _controlFocused)
-            {
-                _controlFocused = null;
-            }
+            if (control != ControlFocused) return;
+            ControlFocused?.ControlFocusExited();
+            ControlFocused = null;
         }
 
         public void PushModal(Control modal)
@@ -569,7 +568,7 @@ namespace Robust.Client.UserInterface
 
         public void CursorChanged(Control control)
         {
-            if (control == _controlFocused || control == CurrentlyHovered)
+            if (control == ControlFocused || control == CurrentlyHovered)
             {
                 _needUpdateActiveCursor = true;
             }

Robust.Client/UserInterface/XAML/Attributes.cs

@@ -0,0 +1,42 @@
+using System;
+
+namespace Robust.Client.UserInterface.XAML
+{
+    public class ContentAttribute : Attribute
+    {
+    }
+
+    public class XmlnsDefinitionAttribute : Attribute
+    {
+        public XmlnsDefinitionAttribute(string xmlNamespace, string clrNamespace)
+        {
+        }
+    }
+
+    public class UsableDuringInitializationAttribute : Attribute
+    {
+        public UsableDuringInitializationAttribute(bool usable)
+        {
+        }
+    }
+
+    public class DeferredContentAttribute : Attribute
+    {
+    }
+
+    public interface ITestRootObjectProvider
+    {
+        object RootObject { get; }
+    }
+
+    public interface ITestProvideValueTarget
+    {
+        object TargetObject { get; }
+        object TargetProperty { get; }
+    }
+
+    public interface ITestUriContext
+    {
+        Uri BaseUri { get; set; }
+    }
+}

Robust.Client/UserInterface/XAML/NameScope.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Generic;
+
+namespace Robust.Client.UserInterface.XAML
+{
+/// <summary>
+    /// Implements a name scope.
+    /// </summary>
+    public class NameScope
+    {
+        public bool IsCompleted { get; private set; }
+
+        private readonly Dictionary<string, Control> _inner = new Dictionary<string, Control>();
+
+        public void Register(string name, Control element)
+        {
+            if (IsCompleted)
+                throw new InvalidOperationException("NameScope is completed, no further registrations are allowed");
+            if (name == null)
+            {
+                throw new ArgumentNullException(nameof(name));
+            }
+            if (element == null)
+            {
+                throw new ArgumentNullException(nameof(element));
+            }
+
+            if (_inner.TryGetValue(name, out Control? existing))
+            {
+                if (existing != element)
+                {
+                    throw new ArgumentException($"Control with the name '{name}' already registered.");
+                }
+            }
+            else
+            {
+                _inner.Add(name, element);
+            }
+        }
+
+        public void Absorb(NameScope? nameScope)
+        {
+            if (nameScope == null) return;
+
+            foreach (var (name, control) in nameScope._inner)
+            {
+                try
+                {
+                    Register(name, control);
+                }
+                catch (Exception e)
+                {
+                    throw new ArgumentException($"Exception occured when trying to absorb NameScope (at name {name})", e);
+                }
+            }
+        }
+
+        public Control? Find(string name)
+        {
+            if (name == null)
+                throw new ArgumentNullException(nameof(name));
+
+            _inner.TryGetValue(name, out var result);
+            return result;
+        }
+
+        public void Complete()
+        {
+            IsCompleted = true;
+        }
+    }
+}

Robust.Client/UserInterface/XAML/RobustXamlLoader.cs

@@ -0,0 +1,13 @@
+using System;
+
+namespace Robust.Client.UserInterface.XAML
+{
+    public class RobustXamlLoader
+    {
+        public static void Load(object obj)
+        {
+            throw new Exception(
+                $"No precompiled XAML found for {obj.GetType()}, make sure to specify Class or name your class the same as your .xaml ");
+        }
+    }
+}

Robust.Client/Utility/UserDataDir.cs

@@ -4,7 +4,7 @@ using JetBrains.Annotations;
 
 namespace Robust.Client.Utility
 {
-    public static class UserDataDir
+    internal static class UserDataDir
     {
         [Pure]
         public static string GetUserDataDir()

Robust.Client/ViewVariables/Instances/ViewVariablesInstanceEntity.cs

@@ -8,6 +8,7 @@ using Robust.Client.UserInterface.CustomControls;
 using Robust.Client.ViewVariables.Traits;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Serialization;
 using Robust.Shared.Localization;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
@@ -51,7 +52,7 @@ namespace Robust.Client.ViewVariables.Instances
 
         private bool _serverLoaded;
 
-        public ViewVariablesInstanceEntity(IViewVariablesManagerInternal vvm, IResourceCache resCache, IEntityManager entityManager) : base(vvm, resCache)
+        public ViewVariablesInstanceEntity(IViewVariablesManagerInternal vvm, IEntityManager entityManager, IRobustSerializer robustSerializer) : base(vvm, robustSerializer)
         {
             _entityManager = entityManager;
         }
@@ -117,7 +118,7 @@ namespace Robust.Client.ViewVariables.Instances
             _tabs.SetTabTitle(TabClientVars, "Client Variables");
 
             var first = true;
-            foreach (var group in LocalPropertyList(obj, ViewVariablesManager, _resourceCache))
+            foreach (var group in LocalPropertyList(obj, ViewVariablesManager, _robustSerializer))
             {
                 ViewVariablesTraitMembers.CreateMemberGroupHeader(
                     ref first,
@@ -202,7 +203,7 @@ namespace Robust.Client.ViewVariables.Instances
                     button.Visible = false;
                     continue;
                 }
-                
+
                 button.Visible = true;
             }
         }
@@ -231,7 +232,7 @@ namespace Robust.Client.ViewVariables.Instances
                     button.Visible = false;
                     continue;
                 }
-                
+
                 if (!button.Text.Contains(searchStr, StringComparison.InvariantCultureIgnoreCase))
                 {
                     button.Visible = false;
@@ -314,7 +315,7 @@ namespace Robust.Client.ViewVariables.Instances
 
                 foreach (var propertyData in groupMembers)
                 {
-                    var propertyEdit = new ViewVariablesPropertyControl(ViewVariablesManager, _resourceCache);
+                    var propertyEdit = new ViewVariablesPropertyControl(ViewVariablesManager, _robustSerializer);
                     propertyEdit.SetStyle(otherStyle = !otherStyle);
                     var editor = propertyEdit.SetProperty(propertyData);
                     var selectorChain = new object[] {new ViewVariablesMemberSelector(propertyData.PropertyIndex)};
@@ -328,7 +329,7 @@ namespace Robust.Client.ViewVariables.Instances
             var componentsBlob = await ViewVariablesManager.RequestData<ViewVariablesBlobEntityComponents>(_entitySession, new ViewVariablesRequestEntityComponents());
 
             _serverComponents.DisposeAllChildren();
-            
+
             _serverComponents.AddChild(_serverComponentsSearchBar = new LineEdit
             {
                 PlaceHolder = Loc.GetString("Search"),
@@ -336,7 +337,7 @@ namespace Robust.Client.ViewVariables.Instances
             });
 
             _serverComponentsSearchBar.OnTextChanged += OnServerComponentsSearchBarChanged;
-            
+
             componentsBlob.ComponentTypes.Sort();
 
             var componentTypes = componentsBlob.ComponentTypes.AsEnumerable();

Robust.Client/ViewVariables/Instances/ViewVariablesInstanceObject.cs

@@ -4,6 +4,7 @@ using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Client.UserInterface.CustomControls;
 using Robust.Client.ViewVariables.Traits;
+using Robust.Shared.Interfaces.Serialization;
 using Robust.Shared.ViewVariables;
 using Robust.Shared.Utility;
 
@@ -19,8 +20,8 @@ namespace Robust.Client.ViewVariables.Instances
         public ViewVariablesRemoteSession? Session { get; private set; }
         public object? Object { get; private set; }
 
-        public ViewVariablesInstanceObject(IViewVariablesManagerInternal vvm, IResourceCache resCache)
-            : base(vvm, resCache) { }
+        public ViewVariablesInstanceObject(IViewVariablesManagerInternal vvm, IRobustSerializer robustSerializer)
+            : base(vvm, robustSerializer) { }
 
         public override void Initialize(SS14Window window, object obj)
         {
@@ -113,7 +114,7 @@ namespace Robust.Client.ViewVariables.Instances
             var list = new List<ViewVariablesTrait>(traitData.Count);
             if (traitData.Contains(ViewVariablesTraits.Members))
             {
-                list.Add(new ViewVariablesTraitMembers(ViewVariablesManager, _resourceCache));
+                list.Add(new ViewVariablesTraitMembers(ViewVariablesManager, _robustSerializer));
             }
 
             if (traitData.Contains(ViewVariablesTraits.Enumerable))

Robust.Client/ViewVariables/Traits/ViewVariablesTraitMembers.cs

@@ -2,6 +2,7 @@
 using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Client.ViewVariables.Instances;
+using Robust.Shared.Interfaces.Serialization;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
@@ -11,7 +12,7 @@ namespace Robust.Client.ViewVariables.Traits
     internal class ViewVariablesTraitMembers : ViewVariablesTrait
     {
         private readonly IViewVariablesManagerInternal _vvm;
-        private readonly IResourceCache _resourceCache;
+        private readonly IRobustSerializer _robustSerializer;
 
         private VBoxContainer _memberList = default!;
 
@@ -22,9 +23,9 @@ namespace Robust.Client.ViewVariables.Traits
             instance.AddTab("Members", _memberList);
         }
 
-        public ViewVariablesTraitMembers(IViewVariablesManagerInternal vvm, IResourceCache resourceCache)
+        public ViewVariablesTraitMembers(IViewVariablesManagerInternal vvm, IRobustSerializer robustSerializer)
         {
-            _resourceCache = resourceCache;
+            _robustSerializer = robustSerializer;
             _vvm = vvm;
         }
 
@@ -36,7 +37,7 @@ namespace Robust.Client.ViewVariables.Traits
             {
                 var first = true;
                 foreach (var group in ViewVariablesInstance.LocalPropertyList(Instance.Object,
-                    Instance.ViewVariablesManager, _resourceCache))
+                    Instance.ViewVariablesManager, _robustSerializer))
                 {
                     CreateMemberGroupHeader(
                         ref first,
@@ -64,7 +65,7 @@ namespace Robust.Client.ViewVariables.Traits
 
                     foreach (var propertyData in groupMembers)
                     {
-                        var propertyEdit = new ViewVariablesPropertyControl(_vvm, _resourceCache);
+                        var propertyEdit = new ViewVariablesPropertyControl(_vvm, _robustSerializer);
                         propertyEdit.SetStyle(otherStyle = !otherStyle);
                         var editor = propertyEdit.SetProperty(propertyData);
 

Robust.Client/ViewVariables/ViewVariablesInstance.cs

@@ -7,6 +7,7 @@ using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Client.UserInterface.CustomControls;
 using Robust.Client.ViewVariables.Traits;
+using Robust.Shared.Interfaces.Serialization;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
@@ -19,12 +20,12 @@ namespace Robust.Client.ViewVariables
     internal abstract class ViewVariablesInstance
     {
         public readonly IViewVariablesManagerInternal ViewVariablesManager;
-        protected readonly IResourceCache _resourceCache;
+        protected readonly IRobustSerializer _robustSerializer;
 
-        protected ViewVariablesInstance(IViewVariablesManagerInternal vvm, IResourceCache resCache)
+        protected ViewVariablesInstance(IViewVariablesManagerInternal vvm, IRobustSerializer robustSerializer)
         {
             ViewVariablesManager = vvm;
-            _resourceCache = resCache;
+            _robustSerializer = robustSerializer;
         }
 
         /// <summary>
@@ -54,7 +55,7 @@ namespace Robust.Client.ViewVariables
         }
 
         protected internal static IEnumerable<IGrouping<Type, Control>> LocalPropertyList(object obj, IViewVariablesManagerInternal vvm,
-            IResourceCache resCache)
+            IRobustSerializer robustSerializer)
         {
             var styleOther = false;
             var type = obj.GetType();
@@ -104,7 +105,7 @@ namespace Robust.Client.ViewVariables
                         Value = value
                     };
 
-                    var propertyEdit = new ViewVariablesPropertyControl(vvm, resCache);
+                    var propertyEdit = new ViewVariablesPropertyControl(vvm, robustSerializer);
                     propertyEdit.SetStyle(styleOther = !styleOther);
                     var editor = propertyEdit.SetProperty(data);
                     editor.OnValueChanged += onValueChanged;

Robust.Client/ViewVariables/ViewVariablesManager.cs

@@ -23,7 +23,7 @@ namespace Robust.Client.ViewVariables
     internal class ViewVariablesManager : ViewVariablesManagerShared, IViewVariablesManagerInternal
     {
         [Dependency] private readonly IClientNetManager _netManager = default!;
-        [Dependency] private readonly IResourceCache _resourceCache = default!;
+        [Dependency] private readonly IRobustSerializer _robustSerializer = default!;
         [Dependency] private readonly IEntityManager _entityManager = default!;
 
         private uint _nextReqId = 1;
@@ -214,11 +214,11 @@ namespace Robust.Client.ViewVariables
             ViewVariablesInstance instance;
             if (obj is IEntity entity && !entity.Deleted)
             {
-                instance = new ViewVariablesInstanceEntity(this, _resourceCache, _entityManager);
+                instance = new ViewVariablesInstanceEntity(this, _entityManager, _robustSerializer);
             }
             else
             {
-                instance = new ViewVariablesInstanceObject(this, _resourceCache);
+                instance = new ViewVariablesInstanceObject(this, _robustSerializer);
             }
 
             var window = new SS14Window {Title = "View Variables"};
@@ -255,11 +255,11 @@ namespace Robust.Client.ViewVariables
             ViewVariablesInstance instance;
             if (type != null && typeof(IEntity).IsAssignableFrom(type))
             {
-                instance = new ViewVariablesInstanceEntity(this, _resourceCache, _entityManager);
+                instance = new ViewVariablesInstanceEntity(this, _entityManager, _robustSerializer);
             }
             else
             {
-                instance = new ViewVariablesInstanceObject(this, _resourceCache);
+                instance = new ViewVariablesInstanceObject(this, _robustSerializer);
             }
 
             loadingLabel.Dispose();

Robust.Client/ViewVariables/ViewVariablesPropertyControl.cs

@@ -7,6 +7,7 @@ using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Client.ViewVariables.Editors;
 using Robust.Shared.Input;
+using Robust.Shared.Interfaces.Serialization;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
@@ -23,14 +24,14 @@ namespace Robust.Client.ViewVariables
         private readonly Label _bottomLabel;
 
         private readonly IViewVariablesManagerInternal _viewVariablesManager;
-        private readonly IResourceCache _resourceCache;
+        private readonly IRobustSerializer _robustSerializer;
 
-        public ViewVariablesPropertyControl(IViewVariablesManagerInternal viewVars, IResourceCache resourceCache)
+        public ViewVariablesPropertyControl(IViewVariablesManagerInternal viewVars, IRobustSerializer robustSerializer)
         {
             MouseFilter = MouseFilterMode.Pass;
 
             _viewVariablesManager = viewVars;
-            _resourceCache = resourceCache;
+            _robustSerializer = robustSerializer;
 
             MouseFilter = MouseFilterMode.Pass;
             ToolTip = "Click to expand";
@@ -68,11 +69,11 @@ namespace Robust.Client.ViewVariables
 
             _bottomLabel.Text = $"Type: {member.TypePretty}";
             VVPropEditor editor;
-            if (type == null)
+            if (type == null || !_robustSerializer.CanSerialize(type))
             {
                 // Type is server-side only.
                 // Info whether it's reference or value type can be figured out from the sent value.
-                if (member.Value is ViewVariablesBlobMembers.ServerValueTypeToken)
+                if (type?.IsValueType == true || member.Value is ViewVariablesBlobMembers.ServerValueTypeToken)
                 {
                     // Value type, just display it stringified read-only.
                     editor = new VVPropEditorDummy();
@@ -80,7 +81,7 @@ namespace Robust.Client.ViewVariables
                 else
                 {
                     // Has to be a reference type at this point.
-                    DebugTools.Assert(member.Value is ViewVariablesBlobMembers.ReferenceToken || member.Value == null);
+                    DebugTools.Assert(member.Value is ViewVariablesBlobMembers.ReferenceToken || member.Value == null || type?.IsClass == true || type?.IsInterface == true);
                     editor = _viewVariablesManager.PropertyFor(typeof(object));
                 }
             }

Robust.Server/BaseServer.cs

@@ -1,6 +1,7 @@
-using System;
+using System;
 using System.Diagnostics;
 using System.IO;
+using System.Runtime.InteropServices;
 using System.Threading;
 using Prometheus;
 using Robust.Server.Console;
@@ -37,6 +38,7 @@ using Robust.Shared;
 using Robust.Shared.Network.Messages;
 using Robust.Server.DataMetrics;
 using Robust.Server.Log;
+using Robust.Server.Utility;
 using Robust.Shared.Localization;
 using Robust.Shared.Serialization;
 using Serilog.Debugging;
@@ -286,6 +288,8 @@ namespace Robust.Server
 
             // Initialize Tier 2 services
             IoCManager.Resolve<IGameTiming>().InSimulation = true;
+            
+            IoCManager.Resolve<INetConfigurationManager>().SetupNetworking();
 
             _stateManager.Initialize();
             IoCManager.Resolve<IPlayerManager>().Initialize(MaxPlayers);
@@ -320,6 +324,11 @@ namespace Robust.Server
 
             _stringSerializer.LockStrings();
 
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows) && _config.GetCVar(CVars.SysWinTickPeriod) >= 0)
+            {
+                WindowsTickPeriod.TimeBeginPeriod((uint) _config.GetCVar(CVars.SysWinTickPeriod));
+            }
+
             return false;
         }
 
@@ -480,6 +489,8 @@ namespace Robust.Server
         // called right before main loop returns, do all saving/cleanup in here
         private void Cleanup()
         {
+            IoCManager.Resolve<INetConfigurationManager>().FlushMessages();
+
             // shut down networking, kicking all players.
             _network.Shutdown($"Server shutting down: {_shutdownReason}");
 
@@ -500,6 +511,11 @@ namespace Robust.Server
             AppDomain.CurrentDomain.ProcessExit -= ProcessExiting;
 
             //TODO: This should prob shutdown all managers in a loop.
+
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows) && _config.GetCVar(CVars.SysWinTickPeriod) >= 0)
+            {
+                WindowsTickPeriod.TimeEndPeriod((uint) _config.GetCVar(CVars.SysWinTickPeriod));
+            }
         }
 
         private string UpdateBps()
@@ -528,6 +544,9 @@ namespace Robust.Server
             ServerCurTick.Set(_time.CurTick.Value);
             ServerCurTime.Set(_time.CurTime.TotalSeconds);
 
+            // These are always the same on the server, there is no prediction.
+            _time.LastRealTick = _time.CurTick;
+
             UpdateTitle();
 
             using (TickUsage.WithLabels("PreEngine").NewTimer())
@@ -535,6 +554,11 @@ namespace Robust.Server
                 _modLoader.BroadcastUpdate(ModUpdateLevel.PreEngine, frameEventArgs);
             }
 
+            using (TickUsage.WithLabels("NetworkedCVar").NewTimer())
+            {
+                IoCManager.Resolve<INetConfigurationManager>().TickProcessMessages();
+            }
+
             using (TickUsage.WithLabels("Timers").NewTimer())
             {
                 timerManager.UpdateTimers(frameEventArgs);

Robust.Server/Console/Commands/AddCompCommand.cs

@@ -38,6 +38,7 @@ namespace Robust.Server.Console.Commands
         }
     }
 
+    [UsedImplicitly]
     internal sealed class RemoveCompCommand : IClientCommand
     {
         public string Command => "rmcomp";

Robust.Server/GameObjects/Components/Appearance/AppearanceComponent.cs

@@ -40,17 +40,17 @@ namespace Robust.Server.GameObjects
             return (T)data[key];
         }
 
-        public override bool TryGetData<T>(Enum key, [MaybeNullWhen(false)] out T data)
+        public override bool TryGetData<T>(Enum key, [NotNullWhen(true)] out T data)
         {
             return TryGetData(key, out data);
         }
 
-        public override bool TryGetData<T>(string key, [MaybeNullWhen(false)] out T data)
+        public override bool TryGetData<T>(string key, [NotNullWhen(true)] out T data)
         {
             return TryGetData(key, out data);
         }
 
-        bool TryGetData<T>(object key, [MaybeNullWhen(false)] out T data)
+        private bool TryGetData<T>(object key, [NotNullWhen(true)] out T data)
         {
             if (this.data.TryGetValue(key, out var dat))
             {

Robust.Server/GameObjects/Components/Light/PointLightComponent.cs

@@ -32,8 +32,11 @@ namespace Robust.Server.GameObjects
             get => _enabled;
             set
             {
-                _enabled = value;
-                Dirty();
+                if (_enabled != value)
+                {
+                    _enabled = value;
+                    Dirty();
+                }
             }
         }
 

Robust.Server/Interfaces/ServerStatus/IStatusHost.cs

@@ -1,14 +1,15 @@
 using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Net;
 using System.Net.Http;
+using Microsoft.Extensions.Primitives;
 using Newtonsoft.Json.Linq;
 
 namespace Robust.Server.Interfaces.ServerStatus
 {
     public delegate bool StatusHostHandler(
-        HttpMethod method,
-        HttpListenerRequest request,
-        HttpListenerResponse response);
+        IStatusHandlerContext context);
 
     public interface IStatusHost
     {
@@ -32,4 +33,30 @@ namespace Robust.Server.Interfaces.ServerStatus
         /// </summary>
         event Action<JObject> OnInfoRequest;
     }
+
+    public interface IStatusHandlerContext
+    {
+        HttpMethod RequestMethod { get; }
+        IPEndPoint RemoteEndPoint { get; }
+        Uri Url { get; }
+        bool IsGetLike { get; }
+        IReadOnlyDictionary<string, StringValues> RequestHeaders { get; }
+
+        [return: MaybeNull]
+        public T RequestBodyJson<T>();
+
+        void Respond(
+            string text,
+            HttpStatusCode code = HttpStatusCode.OK,
+            string contentType = "text/plain");
+
+        void Respond(
+            string text,
+            int code = 200,
+            string contentType = "text/plain");
+
+        void RespondError(HttpStatusCode code);
+
+        void RespondJson(object jsonData, HttpStatusCode code = HttpStatusCode.OK);
+    }
 }

Robust.Server/Placement/PlacementManager.cs

@@ -11,6 +11,7 @@ using System.Linq;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.Network;
+using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Network.Messages;
 
@@ -88,6 +89,12 @@ namespace Robust.Server.Placement
 
             var coordinates = msg.EntityCoordinates;
 
+            if (!coordinates.IsValid(_entityManager))
+            {
+                Logger.WarningS("placement",
+                    $"{session} tried to place {msg.ObjType} at invalid coordinate {coordinates}");
+                return;
+            }
 
             /* TODO: Redesign permission system, or document what this is supposed to be doing
             var permission = GetPermission(session.attachedEntity.Uid, alignRcv);

Robust.Server/Player/PlayerManager.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
@@ -7,6 +7,7 @@ using System.Threading.Tasks;
 using Prometheus;
 using Robust.Server.Interfaces;
 using Robust.Server.Interfaces.Player;
+using Robust.Shared.Configuration;
 using Robust.Shared.Enums;
 using Robust.Shared.GameStates;
 using Robust.Shared.Input;
@@ -91,8 +92,6 @@ namespace Robust.Server.Player
 
             MaxPlayers = maxPlayers;
 
-            _network.RegisterNetMessage<MsgServerInfoReq>(MsgServerInfoReq.NAME, HandleWelcomeMessageReq);
-            _network.RegisterNetMessage<MsgServerInfo>(MsgServerInfo.NAME);
             _network.RegisterNetMessage<MsgPlayerListReq>(MsgPlayerListReq.NAME, HandlePlayerListReq);
             _network.RegisterNetMessage<MsgPlayerList>(MsgPlayerList.NAME);
 
@@ -378,6 +377,8 @@ namespace Robust.Server.Player
             }
 
             PlayerCountMetric.Set(PlayerCount);
+
+            IoCManager.Resolve<INetConfigurationManager>().SyncConnectingClient(args.Channel);
         }
 
         private void OnPlayerStatusChanged(IPlayerSession session, SessionStatus oldStatus, SessionStatus newStatus)
@@ -414,18 +415,6 @@ namespace Robust.Server.Player
             Dirty();
         }
 
-        private void HandleWelcomeMessageReq(MsgServerInfoReq message)
-        {
-            var channel = message.MsgChannel;
-            var netMsg = channel.CreateNetMessage<MsgServerInfo>();
-
-            netMsg.ServerName = _baseServer.ServerName;
-            netMsg.ServerMaxPlayers = _baseServer.MaxPlayers;
-            netMsg.TickRate = _timing.TickRate;
-
-            channel.SendMessage(netMsg);
-        }
-
         private void HandlePlayerListReq(MsgPlayerListReq message)
         {
             var channel = message.MsgChannel;

Robust.Server/Robust.Server.csproj

@@ -14,9 +14,11 @@
     <PackageReference Include="Microsoft.Data.Sqlite" Version="5.0.0" />
     <PackageReference Include="prometheus-net" Version="4.0.0" />
     <PackageReference Include="Serilog.Sinks.Loki" Version="3.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Primitives" Version="5.0.0" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Lidgren.Network\Lidgren.Network.csproj" />
+    <ProjectReference Include="..\ManagedHttpListener\src\System.Net.HttpListener.csproj" />
     <ProjectReference Include="..\Robust.Physics\Robust.Physics.csproj" />
     <ProjectReference Include="..\Robust.Shared.Maths\Robust.Shared.Maths.csproj" />
     <ProjectReference Include="..\Robust.Shared.Scripting\Robust.Shared.Scripting.csproj" />

Robust.Server/ServerStatus/StatusHost.Handlers.cs

@@ -1,11 +1,8 @@
 using System;
-using System.IO;
 using System.Net;
-using System.Net.Http;
-using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
+using Robust.Server.Interfaces.ServerStatus;
 using Robust.Shared;
-using Robust.Shared.Utility;
 
 namespace Robust.Server.ServerStatus
 {
@@ -20,69 +17,46 @@ namespace Robust.Server.ServerStatus
             AddHandler(HandleInfo);
         }
 
-        private static bool HandleTeapot(HttpMethod method, HttpListenerRequest request, HttpListenerResponse response)
+        private static bool HandleTeapot(IStatusHandlerContext context)
         {
-            if (!method.IsGetLike() || request.Url!.AbsolutePath != "/teapot")
+            if (!context.IsGetLike || context.Url!.AbsolutePath != "/teapot")
             {
                 return false;
             }
 
-            response.Respond(method, "I am a teapot.", (HttpStatusCode) 418);
+            context.Respond("I am a teapot.", (HttpStatusCode) 418);
             return true;
         }
 
-        private bool HandleStatus(HttpMethod method, HttpListenerRequest request, HttpListenerResponse response)
+        private bool HandleStatus(IStatusHandlerContext context)
         {
-            if (!method.IsGetLike() || request.Url!.AbsolutePath != "/status")
+            if (!context.IsGetLike || context.Url!.AbsolutePath != "/status")
             {
                 return false;
             }
 
-            if (OnStatusRequest == null)
+            var jObject = new JObject
             {
-                _httpSawmill.Warning("OnStatusRequest is not set, responding with a 501.");
-                response.Respond(method, "Not Implemented", HttpStatusCode.NotImplemented);
-                return true;
-            }
-
-            response.StatusCode = (int) HttpStatusCode.OK;
-            response.ContentType = "application/json";
-
-            if (method == HttpMethod.Head)
-            {
-                return true;
-            }
-
-            var jObject = new JObject();
+                // We need to send at LEAST name and player count to have the launcher work with us.
+                // Content can override these if it wants (e.g. stealthmins).
+                ["name"] = _serverNameCache,
+                ["players"] = _playerManager.PlayerCount
+            };
 
             OnStatusRequest?.Invoke(jObject);
 
-            using var streamWriter = new StreamWriter(response.OutputStream, EncodingHelpers.UTF8);
-
-            using var jsonWriter = new JsonTextWriter(streamWriter);
-
-            JsonSerializer.Serialize(jsonWriter, jObject);
-
-            jsonWriter.Flush();
+            context.RespondJson(jObject);
 
             return true;
         }
 
-        private bool HandleInfo(HttpMethod method, HttpListenerRequest request, HttpListenerResponse response)
+        private bool HandleInfo(IStatusHandlerContext context)
         {
-            if (!method.IsGetLike() || request.Url!.AbsolutePath != "/info")
+            if (!context.IsGetLike || context.Url!.AbsolutePath != "/info")
             {
                 return false;
             }
 
-            response.StatusCode = (int) HttpStatusCode.OK;
-            response.ContentType = "application/json";
-
-            if (method == HttpMethod.Head)
-            {
-                return true;
-            }
-
             var downloadUrl = _configurationManager.GetCVar(CVars.BuildDownloadUrl);
 
             JObject? buildInfo;
@@ -126,13 +100,7 @@ namespace Robust.Server.ServerStatus
 
             OnInfoRequest?.Invoke(jObject);
 
-            using var streamWriter = new StreamWriter(response.OutputStream, EncodingHelpers.UTF8);
-
-            using var jsonWriter = new JsonTextWriter(streamWriter);
-
-            JsonSerializer.Serialize(jsonWriter, jObject);
-
-            jsonWriter.Flush();
+            context.RespondJson(jObject);
 
             return true;
         }

Robust.Server/ServerStatus/StatusHost.cs

@@ -1,20 +1,28 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Net;
 using System.Net.Http;
+using System.Net.Mime;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Extensions.Primitives;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
+using Robust.Server.Interfaces.Player;
 using Robust.Server.Interfaces.ServerStatus;
 using Robust.Shared;
+using Robust.Shared.Configuration;
 using Robust.Shared.ContentPack;
 using Robust.Shared.Interfaces.Configuration;
 using Robust.Shared.Interfaces.Log;
 using Robust.Shared.Interfaces.Network;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
+using Robust.Shared.Utility;
+using HttpListener = ManagedHttpListener.HttpListener;
+using HttpListenerContext = ManagedHttpListener.HttpListenerContext;
 
 // This entire file is NIHing a REST server because pulling in libraries is effort.
 // Also it was fun to write.
@@ -28,6 +36,7 @@ namespace Robust.Server.ServerStatus
 
         [Dependency] private readonly IConfigurationManager _configurationManager = default!;
         [Dependency] private readonly IServerNetManager _netManager = default!;
+        [Dependency] private readonly IPlayerManager _playerManager = default!;
 
         private static readonly JsonSerializer JsonSerializer = new();
         private readonly List<StatusHostHandler> _handlers = new();
@@ -35,19 +44,20 @@ namespace Robust.Server.ServerStatus
         private TaskCompletionSource? _stopSource;
         private ISawmill _httpSawmill = default!;
 
+        private string? _serverNameCache;
+
         public Task ProcessRequestAsync(HttpListenerContext context)
         {
-            var response = context.Response;
-            var request = context.Request;
-            var method = new HttpMethod(request.HttpMethod);
+            var apiContext = (IStatusHandlerContext) new ContextImpl(context);
 
-            _httpSawmill.Info($"{method} {context.Request.Url?.PathAndQuery} from {request.RemoteEndPoint}");
+            _httpSawmill.Info(
+                $"{apiContext.RequestMethod} {apiContext.Url.PathAndQuery} from {apiContext.RemoteEndPoint}");
 
             try
             {
                 foreach (var handler in _handlers)
                 {
-                    if (handler(method, request, response))
+                    if (handler(apiContext))
                     {
                         return Task.CompletedTask;
                     }
@@ -55,12 +65,12 @@ namespace Robust.Server.ServerStatus
 
                 // No handler returned true, assume no handlers care about this.
                 // 404.
-                response.Respond(method, "Not Found", HttpStatusCode.NotFound);
+                apiContext.Respond("Not Found", HttpStatusCode.NotFound);
             }
             catch (Exception e)
             {
-                response.Respond(method, "Internal Server Error", HttpStatusCode.InternalServerError);
                 _httpSawmill.Error($"Exception in StatusHost: {e}");
+                apiContext.Respond("Internal Server Error", HttpStatusCode.InternalServerError);
             }
 
             /*
@@ -85,6 +95,10 @@ namespace Robust.Server.ServerStatus
             _httpSawmill = Logger.GetSawmill($"{Sawmill}.http");
             RegisterCVars();
 
+            // Cache this in a field to avoid thread safety shenanigans.
+            // Writes/reads of references are atomic in C# so no further synchronization necessary.
+            _configurationManager.OnValueChanged(CVars.GameHostName, n => _serverNameCache = n);
+
             if (!_configurationManager.GetCVar(CVars.StatusEnabled))
             {
                 return;
@@ -146,15 +160,22 @@ namespace Robust.Server.ServerStatus
                 var buildInfo = File.ReadAllText(PathHelpers.ExecutableRelativeFile("build.json"));
                 var info = JsonConvert.DeserializeObject<BuildInfo>(buildInfo);
 
-                _configurationManager.SetCVar(CVars.BuildEngineVersion, info.EngineVersion);
-                _configurationManager.SetCVar(CVars.BuildForkId, info.ForkId);
-                _configurationManager.SetCVar(CVars.BuildVersion, info.Version);
-                _configurationManager.SetCVar(CVars.BuildDownloadUrl, info.Download);
-                _configurationManager.SetCVar(CVars.BuildHash, info.Hash ?? "");
+                // Don't replace cvars with contents of build.json if overriden by --cvar or such.
+                SetCVarIfUnmodified(CVars.BuildEngineVersion, info.EngineVersion);
+                SetCVarIfUnmodified(CVars.BuildForkId, info.ForkId);
+                SetCVarIfUnmodified(CVars.BuildVersion, info.Version);
+                SetCVarIfUnmodified(CVars.BuildDownloadUrl, info.Download ?? "");
+                SetCVarIfUnmodified(CVars.BuildHash, info.Hash ?? "");
             }
             catch (FileNotFoundException)
             {
             }
+
+            void SetCVarIfUnmodified(CVarDef<string> cvar, string val)
+            {
+                if (_configurationManager.GetCVar(cvar) == "")
+                    _configurationManager.SetCVar(cvar, val);
+            }
         }
 
         public void Dispose()
@@ -168,14 +189,91 @@ namespace Robust.Server.ServerStatus
             _listener!.Stop();
         }
 
+        #pragma warning disable CS0649
         [JsonObject(ItemRequired = Required.DisallowNull)]
         private sealed class BuildInfo
         {
             [JsonProperty("engine_version")] public string EngineVersion = default!;
             [JsonProperty("hash")] public string? Hash;
-            [JsonProperty("download")] public string Download = default!;
+            [JsonProperty("download")] public string? Download = default;
             [JsonProperty("fork_id")] public string ForkId = default!;
             [JsonProperty("version")] public string Version = default!;
         }
+        #pragma warning restore CS0649
+
+        private sealed class ContextImpl : IStatusHandlerContext
+        {
+            private readonly HttpListenerContext _context;
+            public HttpMethod RequestMethod { get; }
+            public IPEndPoint RemoteEndPoint => _context.Request.RemoteEndPoint!;
+            public Uri Url => _context.Request.Url!;
+            public bool IsGetLike => RequestMethod == HttpMethod.Head || RequestMethod == HttpMethod.Get;
+            public IReadOnlyDictionary<string, StringValues> RequestHeaders { get; }
+
+            public ContextImpl(HttpListenerContext context)
+            {
+                _context = context;
+                RequestMethod = new HttpMethod(context.Request.HttpMethod!);
+
+                var headers = new Dictionary<string, StringValues>();
+                foreach (string? key in context.Request.Headers.Keys)
+                {
+                    if (key == null)
+                        continue;
+
+                    headers.Add(key, context.Request.Headers.GetValues(key));
+                }
+
+                RequestHeaders = headers;
+            }
+
+            [return: MaybeNull]
+            public T RequestBodyJson<T>()
+            {
+                using var streamReader = new StreamReader(_context.Request.InputStream, EncodingHelpers.UTF8);
+                using var jsonReader = new JsonTextReader(streamReader);
+
+                var serializer = new JsonSerializer();
+                return serializer.Deserialize<T>(jsonReader);
+            }
+
+            public void Respond(string text, HttpStatusCode code = HttpStatusCode.OK, string contentType = MediaTypeNames.Text.Plain)
+            {
+                Respond(text, (int) code, contentType);
+            }
+
+            public void Respond(string text, int code = 200, string contentType = MediaTypeNames.Text.Plain)
+            {
+                _context.Response.StatusCode = code;
+                _context.Response.ContentType = contentType;
+
+                if (RequestMethod == HttpMethod.Head)
+                {
+                    return;
+                }
+
+                using var writer = new StreamWriter(_context.Response.OutputStream, EncodingHelpers.UTF8);
+
+                writer.Write(text);
+            }
+
+            public void RespondError(HttpStatusCode code)
+            {
+                Respond(code.ToString(), code);
+            }
+
+            public void RespondJson(object jsonData, HttpStatusCode code = HttpStatusCode.OK)
+            {
+                using var streamWriter = new StreamWriter(_context.Response.OutputStream, EncodingHelpers.UTF8);
+
+                _context.Response.ContentType = MediaTypeNames.Application.Json;
+
+                using var jsonWriter = new JsonTextWriter(streamWriter);
+
+                JsonSerializer.Serialize(jsonWriter, jsonData);
+
+                jsonWriter.Flush();
+            }
+        }
     }
 }

Robust.Server/ServerStatus/StatusHostHelpers.cs

@@ -1,7 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Net;
-using System.Net.Http;
 using Newtonsoft.Json;
 using Robust.Shared.Utility;
 
@@ -9,41 +8,6 @@ namespace Robust.Server.ServerStatus
 {
     public static class StatusHostHelpers
     {
-        public static bool IsGetLike(this HttpMethod method)
-        {
-            return method == HttpMethod.Get || method == HttpMethod.Head;
-        }
-
-        public static void Respond(
-            this HttpListenerResponse response,
-            HttpMethod method,
-            string text,
-            HttpStatusCode code = HttpStatusCode.OK,
-            string contentType = "text/plain")
-        {
-            response.Respond(method, text, (int) code, contentType);
-        }
-
-        public static void Respond(
-            this HttpListenerResponse response,
-            HttpMethod method,
-            string text,
-            int code = 200,
-            string contentType = "text/plain")
-        {
-            response.StatusCode = code;
-            response.ContentType = contentType;
-
-            if (method == HttpMethod.Head)
-            {
-                return;
-            }
-
-            using var writer = new StreamWriter(response.OutputStream, EncodingHelpers.UTF8);
-
-            writer.Write(text);
-        }
-
         [return: MaybeNull]
         public static T GetFromJson<T>(this HttpListenerRequest request)
         {

Robust.Server/ServerStatus/WatchdogApi.cs

@@ -45,9 +45,9 @@ namespace Robust.Server.ServerStatus
             _statusHost.AddHandler(ShutdownHandler);
         }
 
-        private bool UpdateHandler(HttpMethod method, HttpListenerRequest request, HttpListenerResponse response)
+        private bool UpdateHandler(IStatusHandlerContext context)
         {
-            if (method != HttpMethod.Post || request.Url!.AbsolutePath != "/update")
+            if (context.RequestMethod != HttpMethod.Post || context.Url!.AbsolutePath != "/update")
             {
                 return false;
             }
@@ -58,26 +58,26 @@ namespace Robust.Server.ServerStatus
                 return false;
             }
 
-            var auth = request.Headers["WatchdogToken"];
+            var auth = context.RequestHeaders["WatchdogToken"];
 
             if (auth != _watchdogToken)
             {
                 // Holy shit nobody read these logs please.
                 _sawmill.Info(@"Failed auth: ""{0}"" vs ""{1}""", auth, _watchdogToken);
-                response.StatusCode = (int) HttpStatusCode.Unauthorized;
+                context.RespondError(HttpStatusCode.Unauthorized);
                 return true;
             }
 
             _taskManager.RunOnMainThread(() => UpdateReceived?.Invoke());
 
-            response.StatusCode = (int) HttpStatusCode.OK;
+            context.Respond("Success", HttpStatusCode.OK);
 
             return true;
         }
 
-        private bool ShutdownHandler(HttpMethod method, HttpListenerRequest request, HttpListenerResponse response)
+        private bool ShutdownHandler(IStatusHandlerContext context)
         {
-            if (method != HttpMethod.Post || request.Url!.AbsolutePath != "/shutdown")
+            if (context.RequestMethod != HttpMethod.Post || context.Url!.AbsolutePath != "/shutdown")
             {
                 return false;
             }
@@ -88,22 +88,21 @@ namespace Robust.Server.ServerStatus
                 return false;
             }
 
-            var auth = request.Headers["WatchdogToken"];
+            var auth = context.RequestHeaders["WatchdogToken"];
 
             if (auth != _watchdogToken)
             {
                 _sawmill.Warning(
                     "received POST /shutdown with invalid authentication token. Ignoring {0}, {1}", auth,
                     _watchdogToken);
-                response.StatusCode = (int) HttpStatusCode.Unauthorized;
+                context.RespondError(HttpStatusCode.Unauthorized);
                 return true;
             }
 
-
             ShutdownParameters? parameters = null;
             try
             {
-                parameters = request.GetFromJson<ShutdownParameters>();
+                parameters = context.RequestBodyJson<ShutdownParameters>();
             }
             catch (JsonSerializationException)
             {
@@ -112,14 +111,14 @@ namespace Robust.Server.ServerStatus
 
             if (parameters == null)
             {
-                response.StatusCode = (int) HttpStatusCode.BadRequest;
+                context.RespondError(HttpStatusCode.BadRequest);
 
                 return true;
             }
 
             _taskManager.RunOnMainThread(() => _baseServer.Shutdown(parameters.Reason));
 
-            response.StatusCode = (int) HttpStatusCode.OK;
+            context.Respond("Success", HttpStatusCode.OK);
 
             return true;
         }

Robust.Server/Utility/WindowsTickPeriod.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace Robust.Server.Utility
+{
+    internal static class WindowsTickPeriod
+    {
+        private const uint TIMERR_NOERROR = 0;
+        // This is an actual error code my god.
+        private const uint TIMERR_NOCANDO = 97;
+
+        public static void TimeBeginPeriod(uint period)
+        {
+            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+                throw new InvalidOperationException();
+
+            var ret = timeBeginPeriod(period);
+            if (ret != TIMERR_NOERROR)
+                throw new InvalidOperationException($"timeBeginPeriod returned error: {ret}");
+        }
+
+        public static void TimeEndPeriod(uint period)
+        {
+            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+                throw new InvalidOperationException();
+
+            var ret = timeEndPeriod(period);
+            if (ret != TIMERR_NOERROR)
+                throw new InvalidOperationException($"timeEndPeriod returned error: {ret}");
+        }
+
+        [DllImport("Winmm.dll")]
+        private static extern uint timeBeginPeriod(uint uPeriod);
+
+        [DllImport("Winmm.dll")]
+        private static extern uint timeEndPeriod(uint uPeriod);
+    }
+}

Robust.Shared.Scripting/ScriptGlobalsShared.cs

@@ -38,7 +38,7 @@ namespace Robust.Shared.Scripting
             {
                 return new EntityCoordinates(EntityUid.Invalid, ((float) x, (float) y));
             }
-            
+
             return new EntityCoordinates(grid.GridEntityId, ((float) x, (float) y));
         }
 
@@ -52,6 +52,11 @@ namespace Robust.Shared.Scripting
             return getent(eid(i));
         }
 
+        public T gcm<T>(int i)
+        {
+            return getent(i).GetComponent<T>();
+        }
+
         public IEntity getent(EntityUid uid)
         {
             return ent.GetEntity(uid);

Robust.Shared/CVars.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Runtime.InteropServices;
 using Robust.Shared.Configuration;
 using Robust.Shared.Log;
 
@@ -59,8 +60,19 @@ namespace Robust.Shared
         public static readonly CVarDef<bool> NetPredict =
             CVarDef.Create("net.predict", true, CVar.ARCHIVE);
 
-        public static readonly CVarDef<int> NetPredictSize =
-            CVarDef.Create("net.predict_size", 1, CVar.ARCHIVE);
+        public static readonly CVarDef<int> NetPredictTickBias =
+            CVarDef.Create("net.predict_tick_bias", 1, CVar.ARCHIVE);
+
+        // On Windows we default this to 16ms lag bias, to account for time period lag in the Lidgren thread.
+        // Basically due to how time periods work on Windows, messages are (at worst) time period-delayed when sending.
+        // BUT! Lidgren's latency calculation *never* measures this due to how it works.
+        // This broke some prediction calculations quite badly so we bias them to mask it.
+        // This is not necessary on Linux because Linux, for better or worse,
+        // just has the Lidgren thread go absolute brr polling.
+        public static readonly CVarDef<float> NetPredictLagBias = CVarDef.Create(
+                "net.predict_lag_bias",
+                RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? 0.016f : 0,
+                CVar.ARCHIVE);
 
         public static readonly CVarDef<int> NetStateBufMergeThreshold =
             CVarDef.Create("net.state_buf_merge_threshold", 5, CVar.ARCHIVE);
@@ -77,6 +89,8 @@ namespace Robust.Shared
         public static readonly CVarDef<int> NetTickrate =
             CVarDef.Create("net.tickrate", 60, CVar.ARCHIVE | CVar.REPLICATED | CVar.SERVER);
 
+        public static readonly CVarDef<int> SysWinTickPeriod =
+            CVarDef.Create("sys.win_tick_period", 3, CVar.SERVERONLY);
 
 #if DEBUG
         public static readonly CVarDef<float> NetFakeLoss = CVarDef.Create("net.fakeloss", 0f, CVar.CHEAT);
@@ -151,10 +165,10 @@ namespace Robust.Shared
          */
 
         public static readonly CVarDef<int> GameMaxPlayers =
-            CVarDef.Create("game.maxplayers", 32, CVar.ARCHIVE | CVar.SERVERONLY);
+            CVarDef.Create("game.maxplayers", 32, CVar.ARCHIVE | CVar.REPLICATED | CVar.SERVER);
 
         public static readonly CVarDef<string> GameHostName =
-            CVarDef.Create("game.hostname", "MyServer", CVar.ARCHIVE | CVar.SERVERONLY);
+            CVarDef.Create("game.hostname", "MyServer", CVar.ARCHIVE | CVar.REPLICATED | CVar.SERVER);
 
         /*
          * LOG
@@ -233,10 +247,10 @@ namespace Robust.Shared
             CVarDef.Create("display.height", 720, CVar.CLIENTONLY);
 
         public static readonly CVarDef<int> DisplayLightMapDivider =
-            CVarDef.Create("display.lightmapdivider", 2, CVar.CLIENTONLY);
+            CVarDef.Create("display.lightmapdivider", 2, CVar.CLIENTONLY | CVar.ARCHIVE);
 
         public static readonly CVarDef<bool> DisplaySoftShadows =
-            CVarDef.Create("display.softshadows", true, CVar.CLIENTONLY);
+            CVarDef.Create("display.softshadows", true, CVar.CLIENTONLY | CVar.ARCHIVE);
 
         public static readonly CVarDef<float> DisplayUIScale =
             CVarDef.Create("display.uiScale", 0f, CVar.ARCHIVE | CVar.CLIENTONLY);
@@ -261,7 +275,7 @@ namespace Robust.Shared
             CVarDef.Create("audio.device", string.Empty, CVar.CLIENTONLY);
 
         public static readonly CVarDef<float> AudioMasterVolume =
-            CVarDef.Create("audio.mastervolume", 1.0f, CVar.CLIENTONLY);
+            CVarDef.Create("audio.mastervolume", 1.0f, CVar.ARCHIVE | CVar.CLIENTONLY);
 
         /*
          * PLAYER

Robust.Shared/Configuration/ConfigurationManager.cs

@@ -1,4 +1,4 @@
-using Nett;
+using Nett;
 using Robust.Shared.Interfaces.Configuration;
 using Robust.Shared.Log;
 using System;
@@ -13,12 +13,12 @@ namespace Robust.Shared.Configuration
     /// <summary>
     ///     Stores and manages global configuration variables.
     /// </summary>
-    internal sealed class ConfigurationManager : IConfigurationManagerInternal
+    internal class ConfigurationManager : IConfigurationManagerInternal
     {
         private const char TABLE_DELIMITER = '.';
-        private readonly Dictionary<string, ConfigVar> _configVars = new();
+        protected readonly Dictionary<string, ConfigVar> _configVars = new();
         private string? _configFile;
-        private bool _isServer;
+        protected bool _isServer;
 
         /// <summary>
         ///     Constructs a new ConfigurationManager.
@@ -79,6 +79,7 @@ namespace Robust.Shared.Configuration
             else // this is a key, add CVar
             {
                 // if the CVar has already been registered
+                var tomlValue = TypeConvert(obj);
                 if (_configVars.TryGetValue(tablePath, out var cfgVar))
                 {
                     if ((cfgVar.Flags & CVar.SECURE) != 0)
@@ -90,13 +91,14 @@ namespace Robust.Shared.Configuration
                         return;
                     }
                     // overwrite the value with the saved one
-                    cfgVar.Value = TypeConvert(obj);
+                    cfgVar.Value = tomlValue;
                     cfgVar.ValueChanged?.Invoke(cfgVar.Value);
                 }
                 else
                 {
                     //or add another unregistered CVar
-                    cfgVar = new ConfigVar(tablePath, null, CVar.NONE) { Value = TypeConvert(obj) };
+                    //Note: the defaultValue is arbitrarily 0, it will get overwritten when the cvar is registered.
+                    cfgVar = new ConfigVar(tablePath, 0, CVar.NONE) { Value = tomlValue };
                     _configVars.Add(tablePath, cfgVar);
                 }
 
@@ -131,6 +133,8 @@ namespace Robust.Shared.Configuration
                         continue;
                     }
 
+                    // Don't write if Archive flag is not set.
+                    // Don't write if the cVar is the default value.
                     if (!cVar.ConfigModified &&
                         (cVar.Flags & CVar.ARCHIVE) == 0 || value.Equals(cVar.DefaultValue))
                     {
@@ -192,6 +196,7 @@ namespace Robust.Shared.Configuration
         }
 
         public void RegisterCVar<T>(string name, T defaultValue, CVar flags = CVar.NONE, Action<T>? onValueChanged = null)
+            where T : notnull
         {
             Action<object>? valueChangedDelegate = null;
             if (onValueChanged != null)
@@ -202,7 +207,7 @@ namespace Robust.Shared.Configuration
             RegisterCVar(name, typeof(T), defaultValue, flags, valueChangedDelegate);
         }
 
-        private void RegisterCVar(string name, Type type, object? defaultValue, CVar flags, Action<object>? onValueChanged)
+        private void RegisterCVar(string name, Type type, object defaultValue, CVar flags, Action<object>? onValueChanged)
         {
             DebugTools.Assert(!type.IsEnum || type.GetEnumUnderlyingType() == typeof(int),
                 $"{name}: Enum cvars must have int as underlying type.");
@@ -305,10 +310,15 @@ namespace Robust.Shared.Configuration
         }
 
         /// <inheritdoc />
-        public void SetCVar(string name, object value)
+        public virtual void SetCVar(string name, object value)
+        {
+            SetCVarInternal(name, value);
+        }
+
+        private void SetCVarInternal(string name, object value, bool allowSecure = false)
         {
             //TODO: Make flags work, required non-derpy net system.
-            if (_configVars.TryGetValue(name, out var cVar) && cVar.Registered && (cVar.Flags & CVar.SECURE) == 0)
+            if (_configVars.TryGetValue(name, out var cVar) && cVar.Registered && (allowSecure || (cVar.Flags & CVar.SECURE) == 0))
             {
                 if (!Equals(cVar.OverrideValueParsed ?? cVar.Value, value))
                 {
@@ -348,6 +358,18 @@ namespace Robust.Shared.Configuration
             throw new InvalidConfigurationException($"Trying to get unregistered variable '{name}'");
         }
 
+        public void SetSecureCVar(string name, object value)
+        {
+            SetCVarInternal(name, value, allowSecure: true);
+        }
+
+
+        public void SetSecureCVar<T>(CVarDef<T> def, T value) where T : notnull
+        {
+            SetSecureCVar(def.Name, value);
+        }
+
+
         public T GetCVar<T>(CVarDef<T> def) where T : notnull
         {
             return GetCVar<T>(def.Name);
@@ -377,13 +399,14 @@ namespace Robust.Shared.Configuration
                 else
                 {
                     //or add another unregistered CVar
-                    var cVar = new ConfigVar(key, null, CVar.NONE) { OverrideValue = value };
+                    //Note: the defaultValue is arbitrarily 0, it will get overwritten when the cvar is registered.
+                    var cVar = new ConfigVar(key, 0, CVar.NONE) { OverrideValue = value };
                     _configVars.Add(key, cVar);
                 }
             }
         }
 
-        private object ParseOverrideValue(string value, Type? type)
+        private static object ParseOverrideValue(string value, Type? type)
         {
             if (type == typeof(int))
             {
@@ -434,7 +457,7 @@ namespace Robust.Shared.Configuration
         /// <summary>
         ///     Holds the data for a single configuration variable.
         /// </summary>
-        private class ConfigVar
+        protected class ConfigVar
         {
             /// <summary>
             ///     Constructs a CVar.
@@ -444,7 +467,7 @@ namespace Robust.Shared.Configuration
             /// everything after is the CVar name in the TOML document.</param>
             /// <param name="defaultValue">The default value of this CVar.</param>
             /// <param name="flags">Optional flags to modify the behavior of this CVar.</param>
-            public ConfigVar(string name, object? defaultValue, CVar flags)
+            public ConfigVar(string name, object defaultValue, CVar flags)
             {
                 Name = name;
                 DefaultValue = defaultValue;
@@ -459,7 +482,7 @@ namespace Robust.Shared.Configuration
             /// <summary>
             ///     The default value of this CVar.
             /// </summary>
-            public object? DefaultValue { get; set; }
+            public object DefaultValue { get; set; }
 
             /// <summary>
             ///     Optional flags to modify the behavior of this CVar.

Robust.Shared/Configuration/NetConfigurationManager.cs

@@ -0,0 +1,311 @@
+using System;
+using System.Collections.Generic;
+using Robust.Shared.Interfaces.Configuration;
+using Robust.Shared.Interfaces.Network;
+using Robust.Shared.Interfaces.Timing;
+using Robust.Shared.IoC;
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Network.Messages;
+using Robust.Shared.Utility;
+
+namespace Robust.Shared.Configuration
+{
+    /// <summary>
+    /// A networked configuration manager that controls the replication of
+    /// console variables between client and server.
+    /// </summary>
+    public interface INetConfigurationManager : IConfigurationManager
+    {
+        /// <summary>
+        /// Sets up the networking for the config manager.
+        /// </summary>
+        void SetupNetworking();
+
+        /// <summary>
+        /// Get a replicated client CVar for a specific client.
+        /// </summary>
+        /// <typeparam name="T">CVar type.</typeparam>
+        /// <param name="channel">channel of the connected client.</param>
+        /// <param name="name">Name of the CVar.</param>
+        /// <returns>Replicated CVar of the client.</returns>
+        T GetClientCVar<T>(INetChannel channel, string name);
+
+        /// <summary>
+        /// Synchronize the CVars marked with <see cref="CVar.REPLICATED"/> with the client.
+        /// This needs to be called once during the client connection.
+        /// </summary>
+        /// <param name="client">Client's NetChannel to sync replicated CVars with.</param>
+        void SyncConnectingClient(INetChannel client);
+
+        /// <summary>
+        /// Synchronize the CVars marked with <see cref="CVar.REPLICATED"/> with the server.
+        /// This needs to be called once when connecting.
+        /// </summary>
+        void SyncWithServer();
+
+        /// <summary>
+        /// Called every tick to process any incoming network messages.
+        /// </summary>
+        void TickProcessMessages();
+
+        /// <summary>
+        /// Flushes any NwCVar messages in the receive buffer.
+        /// </summary>
+        void FlushMessages();
+
+        public event EventHandler ReceivedInitialNwVars;
+    }
+
+    /// <inheritdoc cref="INetConfigurationManager"/>
+    internal class NetConfigurationManager : ConfigurationManager, INetConfigurationManager
+    {
+        [Dependency] private readonly INetManager _netManager = null!;
+        [Dependency] private readonly IGameTiming _timing = null!;
+
+        private readonly Dictionary<INetChannel, Dictionary<string, object>> _replicatedCVars = new();
+        private readonly List<MsgConVars> _netVarsMessages = new();
+
+        public event EventHandler? ReceivedInitialNwVars;
+        private bool _receivedInitialNwVars;
+
+        /// <inheritdoc />
+        public void SetupNetworking()
+        {
+            if(_isServer)
+            {
+                _netManager.Connected += PeerConnected;
+                _netManager.Disconnect += PeerDisconnected;
+            }
+            
+            _netManager.RegisterNetMessage<MsgConVars>(MsgConVars.NAME, HandleNetVarMessage);
+        }
+
+        private void PeerConnected(object? sender, NetChannelArgs e)
+        {
+            _replicatedCVars.Add(e.Channel, new Dictionary<string, object>());
+        }
+
+        private void PeerDisconnected(object? sender, NetDisconnectedArgs e)
+        {
+            _replicatedCVars.Remove(e.Channel);
+        }
+
+        private void HandleNetVarMessage(MsgConVars message)
+        {
+            if(!_receivedInitialNwVars)
+                ReceivedInitialNwVars?.Invoke(this, EventArgs.Empty);
+
+            _receivedInitialNwVars = true;
+            _netVarsMessages.Add(message);
+        }
+
+        /// <inheritdoc />
+        public void TickProcessMessages()
+        {
+            if(!_timing.InSimulation || _timing.InPrediction)
+                return;
+
+            for (var i = 0; i < _netVarsMessages.Count; i++)
+            {
+                var msg = _netVarsMessages[i];
+
+                if (msg.Tick > _timing.LastRealTick)
+                    continue;
+
+                ApplyNetVarChange(msg.MsgChannel, msg.NetworkedVars);
+
+                if(msg.Tick < _timing.LastRealTick)
+                    Logger.WarningS("cfg", $"{msg.MsgChannel}: Received late nwVar message ({msg.Tick} < {_timing.LastRealTick} ).");
+
+                _netVarsMessages.RemoveSwap(i);
+                i--;
+            }
+        }
+
+        /// <inheritdoc />
+        public void FlushMessages()
+        {
+            _netVarsMessages.Sort(((a, b) => a.Tick.Value.CompareTo(b.Tick.Value)));
+
+            foreach (var msg in _netVarsMessages)
+            {
+                ApplyNetVarChange(msg.MsgChannel, msg.NetworkedVars);
+            }
+
+            _netVarsMessages.Clear();
+        }
+        
+        private void ApplyNetVarChange(INetChannel msgChannel, List<(string name, object value)> networkedVars)
+        {
+            Logger.DebugS("cfg", "Handling replicated cvars...");
+
+            foreach (var (name, value) in networkedVars)
+            {
+                if (_netManager.IsClient) // Server sent us a CVar update.
+                {
+                    // Actually set the CVar
+                    base.SetCVar(name, value);
+                    Logger.DebugS("cfg", $"name={name}, val={value}");
+                }
+                else // Client sent us a CVar update
+                {
+                    if (!_configVars.TryGetValue(name, out var cVar))
+                    {
+                        Logger.WarningS("cfg", $"{msgChannel} tried to replicate an unknown CVar '{name}.'");
+                        continue;
+                    }
+
+                    if (!cVar.Registered)
+                    {
+                        Logger.WarningS("cfg", $"{msgChannel} tried to replicate an unregistered CVar '{name}.'");
+                        continue;
+                    }
+
+                    if((cVar.Flags & CVar.REPLICATED) != 0)
+                    {
+                        var clientCVars = _replicatedCVars[msgChannel];
+
+                        if (clientCVars.ContainsKey(name))
+                            clientCVars[name] = value;
+                        else
+                            clientCVars.Add(name, value);
+
+                        Logger.DebugS("cfg", $"name={name}, val={value}");
+                    }
+                    else
+                    {
+                        Logger.WarningS("cfg", $"{msgChannel} tried to replicate an un-replicated CVar '{name}.'");
+                    }
+                }
+            }
+        }
+
+        /// <inheritdoc />
+        public T GetClientCVar<T>(INetChannel channel, string name)
+        {
+            if (!_configVars.TryGetValue(name, out var cVar) || !cVar.Registered)
+                throw new InvalidConfigurationException($"Trying to get unregistered variable '{name}'");
+
+            if (_replicatedCVars.TryGetValue(channel, out var clientCVars) && clientCVars.TryGetValue(name, out var value))
+            {
+                return (T)value;
+            }
+
+            return (T)(cVar.DefaultValue!);
+        }
+
+        /// <inheritdoc />
+        public override void SetCVar(string name, object value)
+        {
+            if (_configVars.TryGetValue(name, out var cVar) && cVar.Registered)
+            {
+                if (_netManager.IsClient)
+                {
+                    if (_netManager.IsConnected)
+                    {
+                        if ((cVar.Flags & CVar.NOT_CONNECTED) != 0)
+                        {
+                            Logger.WarningS("cfg", $"'{name}' can only be changed when not connected to a server.");
+                            return;
+                        }
+                    }
+
+                    if ((cVar.Flags & CVar.SERVER) != 0)
+                    {
+                        Logger.WarningS("cfg", $"Only the server can change '{name}'.");
+                        return;
+                    }
+                }
+            }
+            else
+            {
+                throw new InvalidConfigurationException($"Trying to set unregistered variable '{name}'");
+            }
+
+            // Actually set the CVar
+            base.SetCVar(name, value);
+
+            var cvar = _configVars[name];
+
+            // replicate if needed
+            if (_netManager.IsClient)
+            {
+                if ((cvar.Flags & CVar.REPLICATED) == 0)
+                    return;
+
+                var msg = _netManager.CreateNetMessage<MsgConVars>();
+                msg.Tick = _timing.CurTick;
+                msg.NetworkedVars = new List<(string name, object value)>
+                {
+                    (name, value)
+                };
+                _netManager.ClientSendMessage(msg);
+            }
+            else // Server
+            {
+                if ((cvar.Flags & CVar.REPLICATED) == 0)
+                    return;
+
+                var msg = _netManager.CreateNetMessage<MsgConVars>();
+                msg.Tick = _timing.CurTick;
+                msg.NetworkedVars = new List<(string name, object value)>
+                {
+                    (name, value)
+                };
+                _netManager.ServerSendToAll(msg);
+            }
+        }
+
+        /// <inheritdoc />
+        public void SyncConnectingClient(INetChannel client)
+        {
+            DebugTools.Assert(_netManager.IsConnected);
+            DebugTools.Assert(_netManager.IsServer);
+
+            Logger.InfoS("cfg", $"{client}: Sending server info...");
+
+            var msg = _netManager.CreateNetMessage<MsgConVars>();
+            msg.Tick = _timing.CurTick;
+            msg.NetworkedVars = GetReplicatedVars();
+            _netManager.ServerSendMessage(msg, client);
+        }
+
+        /// <inheritdoc />
+        public void SyncWithServer()
+        {
+            DebugTools.Assert(_netManager.IsConnected);
+            DebugTools.Assert(_netManager.IsClient);
+
+            Logger.InfoS("cfg", "Sending client info...");
+
+            var msg = _netManager.CreateNetMessage<MsgConVars>();
+            msg.Tick = _timing.CurTick;
+            msg.NetworkedVars = GetReplicatedVars();
+            _netManager.ClientSendMessage(msg);
+        }
+
+        private List<(string name, object value)> GetReplicatedVars()
+        {
+            var nwVars = new List<(string name, object value)>();
+
+            foreach (var cVar in _configVars.Values)
+            {
+                if (!cVar.Registered)
+                    return nwVars;
+
+                if ((cVar.Flags & CVar.REPLICATED) == 0)
+                    continue;
+
+                if (_netManager.IsClient && (cVar.Flags & CVar.SERVER) != 0)
+                    continue;
+
+                nwVars.Add((cVar.Name, cVar.Value ?? cVar.DefaultValue));
+
+                Logger.DebugS("cfg", $"name={cVar.Name}, val={(cVar.Value ?? cVar.DefaultValue)}");
+            }
+
+            return nwVars;
+        }
+    }
+}

Robust.Shared/ContentPack/AssemblyTypeChecker.cs

@@ -260,6 +260,11 @@ namespace Robust.Shared.ContentPack
                             // See II.14.2 in ECMA-335.
                             return;
                         }
+                        case MTypeDefined:
+                        {
+                            // Valid for this to show up, safe to ignore.
+                            return;
+                        }
                         default:
                         {
                             throw new ArgumentOutOfRangeException();
@@ -471,6 +476,20 @@ namespace Robust.Shared.ContentPack
 
                             break;
                         }
+                        case HandleKind.TypeDefinition:
+                        {
+                            try
+                            {
+                                parent = GetTypeFromDefinition(reader, (TypeDefinitionHandle) memRef.Parent);
+                            }
+                            catch (UnsupportedMetadataException u)
+                            {
+                                errors.Add(new SandboxError(u));
+                                return null;
+                            }
+
+                            break;
+                        }
                         case HandleKind.TypeSpecification:
                         {
                             var typeSpec = reader.GetTypeSpecification((TypeSpecificationHandle) memRef.Parent);
@@ -501,7 +520,7 @@ namespace Robust.Shared.ContentPack
                         default:
                         {
                             errors.Add(new SandboxError(
-                                $"Unsupported member ref parent type: {memRef.Parent}. Name: {memName}"));
+                                $"Unsupported member ref parent type: {memRef.Parent.Kind}. Name: {memName}"));
                             return null;
                         }
                     }

Robust.Shared/ContentPack/ModLoader.cs

@@ -77,7 +77,7 @@ namespace Robust.Shared.ContentPack
                 var fullPath = mountPath / filePath;
                 Logger.DebugS("res.mod", $"Found module '{fullPath}'");
 
-                var asmFile = _res.ContentFileRead(fullPath);
+                using var asmFile = _res.ContentFileRead(fullPath);
                 var (asmRefs, asmName) = GetAssemblyReferenceData(asmFile);
 
                 if (!files.TryAdd(asmName, (fullPath, asmRefs)))
@@ -118,8 +118,8 @@ namespace Robust.Shared.ContentPack
                     }
                     else
                     {
-                        var assemblyStream = _res.ContentFileRead(path);
-                        var symbolsStream = _res.ContentFileReadOrNull(path.WithExtension("pdb"));
+                        using var assemblyStream = _res.ContentFileRead(path);
+                        using var symbolsStream = _res.ContentFileReadOrNull(path.WithExtension("pdb"));
                         LoadGameAssembly(assemblyStream, symbolsStream, skipVerify: true);
                     }
                 }
@@ -241,16 +241,34 @@ namespace Robust.Shared.ContentPack
 
             if (_res.TryContentFileRead(dllPath, out var gameDll))
             {
-                Logger.DebugS("srv", $"Loading {assemblyName} DLL");
-
-                // see if debug info is present
-                if (_res.TryContentFileRead(new ResourcePath($@"/Assemblies/{assemblyName}.pdb"),
-                    out var gamePdb))
+                using (gameDll)
                 {
+                    Logger.DebugS("srv", $"Loading {assemblyName} DLL");
+
+                    // see if debug info is present
+                    if (_res.TryContentFileRead(new ResourcePath($@"/Assemblies/{assemblyName}.pdb"),
+                        out var gamePdb))
+                    {
+                        using (gamePdb)
+                        {
+                            try
+                            {
+                                // load the assembly into the process, and bootstrap the GameServer entry point.
+                                LoadGameAssembly(gameDll, gamePdb);
+                                return true;
+                            }
+                            catch (Exception e)
+                            {
+                                Logger.ErrorS("srv", $"Exception loading DLL {assemblyName}.dll: {e.ToStringBetter()}");
+                                return false;
+                            }
+                        }
+                    }
+
                     try
                     {
                         // load the assembly into the process, and bootstrap the GameServer entry point.
-                        LoadGameAssembly(gameDll, gamePdb);
+                        LoadGameAssembly(gameDll);
                         return true;
                     }
                     catch (Exception e)
@@ -259,18 +277,6 @@ namespace Robust.Shared.ContentPack
                         return false;
                     }
                 }
-
-                try
-                {
-                    // load the assembly into the process, and bootstrap the GameServer entry point.
-                    LoadGameAssembly(gameDll);
-                    return true;
-                }
-                catch (Exception e)
-                {
-                    Logger.ErrorS("srv", $"Exception loading DLL {assemblyName}.dll: {e.ToStringBetter()}");
-                    return false;
-                }
             }
 
             Logger.WarningS("eng", $"Could not load {assemblyName} DLL: {dllPath} does not exist in the VFS.");

Robust.Shared/ContentPack/ResourceManager.cs

@@ -216,7 +216,13 @@ namespace Robust.Shared.ContentPack
         /// <inheritdoc />
         public bool ContentFileExists(ResourcePath path)
         {
-            return TryContentFileRead(path, out var _);
+            if (TryContentFileRead(path, out var stream))
+            {
+                stream.Dispose();
+                return true;
+            }
+
+            return false;
         }
 
         /// <inheritdoc />

Robust.Shared/ContentPack/Sandbox.yml

@@ -297,6 +297,12 @@ Types:
     IEnumerable: { All: True }
     IEnumerator: { All: True }
     IReadOnlyList`1: { All: True }
+  System.ComponentModel:
+    PropertyDescriptor: { }
+    ISite: { All: True }
+    IComponent: { All: True }
+    IContainer: { All: True }
+    ITypeDescriptorContext: { All: True }
   System.Diagnostics.CodeAnalysis:
     AllowNullAttribute: { All: True }
     DisallowNullAttribute: { All: True }
@@ -436,6 +442,7 @@ Types:
     IsExternalInit: { All: True }
     IsReadOnlyAttribute: { All: True }
     IteratorStateMachineAttribute: { All: True }
+    PreserveBaseOverridesAttribute: { All: True }
     RuntimeCompatibilityAttribute: { All: True }
     RuntimeHelpers: { All: True }
     TaskAwaiter: { All: True }
@@ -651,6 +658,7 @@ Types:
     CancellationTokenSource: { All: True }
     Interlocked: { All: True }
   System:
+    IServiceProvider: { All: True }
     Action: { All: True }
     Action`1: { All: True }
     Action`2: { All: True }
@@ -845,6 +853,7 @@ Types:
     Func`15: { All: True }
     Func`16: { All: True }
     Func`17: { All: True }
+    Guid: { All: True }
     HashCode: { All: True }
     IAsyncDisposable: { All: True }
     IAsyncResult: { }
@@ -1131,6 +1140,7 @@ Types:
       # Content should never touch that.
       Methods:
       - "bool Equals(object)"
+      - "bool Equals(System.Type)"
       - "bool get_ContainsGenericParameters()"
       - "bool get_HasElementType()"
       - "bool get_IsAbstract()"
@@ -1250,6 +1260,7 @@ Types:
     UInt32: { All: True }
     UInt64: { All: True }
     UIntPtr: { All: True }
+    Uri: { All: True }
     ValueTuple: { All: True }
     ValueTuple`1: { All: True }
     ValueTuple`2: { All: True }