Removes some things that should not have been in the last PR.

* AAAAAAAAAAAAA

* Organization

* Still doesnt work

* Formatting

* It works!!

* More changes to everything

* Beginning of changes to overlays

* Makes the overlay manager GUID based (also it was very messy, still messy but i fixed some of it)

* Stencils are easy

* Questionable changes to overlays

* Minor change to HLR

* Fixed duplicate overlays when calling some commands (Like showbb)

* Fixes misleading message

* Adds a variety of worldspaces for overlays to choose from

* Caching

* Address reviews

* Merging pains

* ah.

* ahhhhh

* minor overlaymanager changes

* Work

* fix

* Merge??

* Fixes null errors

* Force update

* Delete whatever the fuck this is?

Co-authored-by: Pieter-Jan Briers <pieterjan.briers+git@gmail.com>

Robust.Client/Debugging/DebugDrawing.cs

@@ -1,8 +1,9 @@
-using System;
+using System;
 using System.Collections.Generic;
 using Robust.Client.Graphics;
 using Robust.Client.Input;
 using Robust.Client.ResourceManagement;
+using Robust.Shared.Enums;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.GameObjects;
@@ -41,14 +42,14 @@ namespace Robust.Client.Debugging
 
                 _debugColliders = value;
 
-                if (value)
+                if (value && !_overlayManager.HasOverlay<PhysicsOverlay>())
                 {
                     _overlayManager.AddOverlay(new PhysicsOverlay(_componentManager, _eyeManager,
                         _prototypeManager, _inputManager, _physicsManager));
                 }
                 else
                 {
-                    _overlayManager.RemoveOverlay(nameof(PhysicsOverlay));
+                    _overlayManager.RemoveOverlay<PhysicsOverlay>();
                 }
             }
         }
@@ -66,13 +67,13 @@ namespace Robust.Client.Debugging
 
                 _debugPositions = value;
 
-                if (value)
+                if (value && !_overlayManager.HasOverlay<EntityPositionOverlay>())
                 {
                     _overlayManager.AddOverlay(new EntityPositionOverlay(_entityManager, _eyeManager));
                 }
                 else
                 {
-                    _overlayManager.RemoveOverlay(nameof(EntityPositionOverlay));
+                    _overlayManager.RemoveOverlay<EntityPositionOverlay>();
                 }
             }
         }
@@ -91,8 +92,8 @@ namespace Robust.Client.Debugging
             private Vector2 _hoverStartScreen = Vector2.Zero;
             private List<IPhysBody> _hoverBodies = new();
 
+
             public PhysicsOverlay(IComponentManager compMan, IEyeManager eyeMan, IPrototypeManager protoMan, IInputManager inputManager, IPhysicsManager physicsManager)
-                : base(nameof(PhysicsOverlay))
             {
                 _componentManager = compMan;
                 _eyeManager = eyeMan;
@@ -265,7 +266,7 @@ namespace Robust.Client.Debugging
 
             public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-            public EntityPositionOverlay(IEntityManager entityManager, IEyeManager eyeManager) : base(nameof(EntityPositionOverlay))
+            public EntityPositionOverlay(IEntityManager entityManager, IEyeManager eyeManager)
             {
                 _entityManager = entityManager;
                 _eyeManager = eyeManager;

Robust.Client/Debugging/DebugDrawingManager.cs

@@ -1,10 +1,11 @@
-using Robust.Shared.IoC;
+using Robust.Shared.IoC;
 using Robust.Shared.Network.Messages;
 using System;
 using System.Collections.Generic;
 using Robust.Client.Graphics;
 using Robust.Shared.Maths;
 using Robust.Shared.Timing;
+using Robust.Shared.Enums;
 using Robust.Shared.Network;
 
 namespace Robust.Client.Debugging
@@ -38,13 +39,13 @@ namespace Robust.Client.Debugging
 
                 _debugDrawRays = value;
 
-                if (value)
+                if (value && !_overlayManager.HasOverlay<DebugDrawRayOverlay>())
                 {
                     _overlayManager.AddOverlay(new DebugDrawRayOverlay(this));
                 }
                 else
                 {
-                    _overlayManager.RemoveOverlay(nameof(DebugDrawRayOverlay));
+                    _overlayManager.RemoveOverlay<DebugDrawRayOverlay>();
                 }
             }
         }
@@ -81,7 +82,7 @@ namespace Robust.Client.Debugging
             private readonly DebugDrawingManager _owner;
             public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-            public DebugDrawRayOverlay(DebugDrawingManager owner) : base(nameof(DebugDrawRayOverlay))
+            public DebugDrawRayOverlay(DebugDrawingManager owner)
             {
                 _owner = owner;
             }

Robust.Client/Debugging/DebugPhysicsSystem.cs

@@ -24,6 +24,7 @@
 
 using System;
 using Robust.Client.Graphics;
+using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
@@ -55,7 +56,7 @@ namespace Robust.Client.Debugging
                     IoCManager.Resolve<IOverlayManager>().AddOverlay(new PhysicsDebugOverlay(this));
 
                 if (value == PhysicsDebugFlags.None)
-                    IoCManager.Resolve<IOverlayManager>().RemoveOverlay(nameof(PhysicsDebugOverlay));
+                    IoCManager.Resolve<IOverlayManager>().RemoveOverlay(typeof(PhysicsDebugOverlay));
 
                 _flags = value;
             }
@@ -119,7 +120,7 @@ namespace Robust.Client.Debugging
 
         public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-        public PhysicsDebugOverlay(DebugPhysicsSystem system) : base(nameof(PhysicsDebugOverlay))
+        public PhysicsDebugOverlay(DebugPhysicsSystem system)
         {
             _physics = system;
         }

Robust.Client/GameObjects/EntitySystems/EffectSystem.cs

@@ -11,6 +11,7 @@ using Robust.Shared.Log;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
+using Robust.Shared.Enums;
 
 namespace Robust.Client.GameObjects
 {
@@ -42,7 +43,7 @@ namespace Robust.Client.GameObjects
         {
             base.Shutdown();
 
-            overlayManager.RemoveOverlay("EffectSystem");
+            overlayManager.RemoveOverlay(typeof(EffectOverlay));
         }
 
         public void CreateEffect(EffectSystemMessage message)
@@ -329,7 +330,6 @@ namespace Robust.Client.GameObjects
         {
             private readonly IPlayerManager _playerManager;
 
-            public override bool AlwaysDirty => true;
             public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
             private readonly ShaderInstance _unshadedShader;
@@ -337,8 +337,7 @@ namespace Robust.Client.GameObjects
             private readonly IMapManager _mapManager;
             private readonly IEntityManager _entityManager;
 
-            public EffectOverlay(EffectSystem owner, IPrototypeManager protoMan, IMapManager mapMan, IPlayerManager playerMan, IEntityManager entityManager) : base(
-                "EffectSystem")
+            public EffectOverlay(EffectSystem owner, IPrototypeManager protoMan, IMapManager mapMan, IPlayerManager playerMan, IEntityManager entityManager)
             {
                 _owner = owner;
                 _unshadedShader = protoMan.Index<ShaderPrototype>("unshaded").Instance();

Robust.Client/GameStates/NetEntityOverlay.cs

@@ -3,6 +3,7 @@ using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
 using Robust.Shared.Configuration;
 using Robust.Shared.Console;
+using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
@@ -33,7 +34,7 @@ namespace Robust.Client.GameStates
         private readonly int _lineHeight;
         private readonly List<NetEntity> _netEnts = new();
 
-        public NetEntityOverlay() : base(nameof(NetEntityOverlay))
+        public NetEntityOverlay()
         {
             IoCManager.InjectDependencies(this);
             var cache = IoCManager.Resolve<IResourceCache>();
@@ -179,11 +180,10 @@ namespace Robust.Client.GameStates
             return Color.Green; // Entity in PVS, but not updated recently.
         }
 
-        protected override void Dispose(bool disposing)
+        protected override void DisposeBehavior()
         {
             _gameStateManager.GameStateApplied -= HandleGameStateApplied;
-
-            base.Dispose(disposing);
+            base.DisposeBehavior();
         }
 
         private static void DrawString(DrawingHandleScreen handle, Font font, Vector2 pos, string str, Color textColor)
@@ -238,14 +238,14 @@ namespace Robust.Client.GameStates
                 var bValue = iValue > 0;
                 var overlayMan = IoCManager.Resolve<IOverlayManager>();
 
-                if(bValue && !overlayMan.HasOverlay(nameof(NetEntityOverlay)))
+                if(bValue && !overlayMan.HasOverlay(typeof(NetEntityOverlay)))
                 {
                     overlayMan.AddOverlay(new NetEntityOverlay());
                     shell.WriteLine("Enabled network entity report overlay.");
                 }
-                else if(!bValue && overlayMan.HasOverlay(nameof(NetEntityOverlay)))
+                else if(!bValue && overlayMan.HasOverlay(typeof(NetEntityOverlay)))
                 {
-                    overlayMan.RemoveOverlay(nameof(NetEntityOverlay));
+                    overlayMan.RemoveOverlay(typeof(NetEntityOverlay));
                     shell.WriteLine("Disabled network entity report overlay.");
                 }
             }

Robust.Client/GameStates/NetGraphOverlay.cs

@@ -1,6 +1,8 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
+using Robust.Shared.Enums;
 using Robust.Shared.Console;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
@@ -34,7 +36,7 @@ namespace Robust.Client.GameStates
 
         private readonly List<(GameTick Tick, int Payload, int lag, int interp)> _history = new(HistorySize+10);
 
-        public NetGraphOverlay() : base(nameof(NetGraphOverlay))
+        public NetGraphOverlay()
         {
             IoCManager.InjectDependencies(this);
             var cache = IoCManager.Resolve<IResourceCache>();
@@ -142,11 +144,11 @@ namespace Robust.Client.GameStates
             DrawString((DrawingHandleScreen)handle, _font, new Vector2(leftMargin, height + LowerGraphOffset), $"{_gameStateManager.CurrentBufferSize.ToString()} states");
         }
 
-        protected override void Dispose(bool disposing)
+        protected override void DisposeBehavior()
         {
             _gameStateManager.GameStateApplied -= HandleGameStateApplied;
 
-            base.Dispose(disposing);
+            base.DisposeBehavior();
         }
 
         private void DrawString(DrawingHandleScreen handle, Font font, Vector2 pos, string str)
@@ -183,14 +185,14 @@ namespace Robust.Client.GameStates
                 var bValue = iValue > 0;
                 var overlayMan = IoCManager.Resolve<IOverlayManager>();
 
-                if(bValue && !overlayMan.HasOverlay(nameof(NetGraphOverlay)))
+                if(bValue && !overlayMan.HasOverlay(typeof(NetGraphOverlay)))
                 {
                     overlayMan.AddOverlay(new NetGraphOverlay());
                     shell.WriteLine("Enabled network overlay.");
                 }
-                else if(overlayMan.HasOverlay(nameof(NetGraphOverlay)))
+                else if(overlayMan.HasOverlay(typeof(NetGraphOverlay)))
                 {
-                    overlayMan.RemoveOverlay(nameof(NetGraphOverlay));
+                    overlayMan.RemoveOverlay(typeof(NetGraphOverlay));
                     shell.WriteLine("Disabled network overlay.");
                 }
             }

Robust.Client/GameStates/NetInterpOverlay.cs

@@ -1,3 +1,4 @@
+using Robust.Shared.Enums;
 using Robust.Client.Graphics;
 using Robust.Shared.Console;
 using Robust.Shared.GameObjects;
@@ -5,6 +6,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Maths;
 using Robust.Shared.Physics;
 using Robust.Shared.Prototypes;
+using System;
 using Robust.Shared.Timing;
 
 namespace Robust.Client.GameStates
@@ -18,7 +20,7 @@ namespace Robust.Client.GameStates
         public override OverlaySpace Space => OverlaySpace.WorldSpace;
         private readonly ShaderInstance _shader;
 
-        public NetInterpOverlay() : base(nameof(NetInterpOverlay))
+        public NetInterpOverlay()
         {
             IoCManager.InjectDependencies(this);
             _shader = _prototypeManager.Index<ShaderPrototype>("unshaded").Instance();
@@ -85,14 +87,14 @@ namespace Robust.Client.GameStates
                 var bValue = iValue > 0;
                 var overlayMan = IoCManager.Resolve<IOverlayManager>();
 
-                if (bValue && !overlayMan.HasOverlay(nameof(NetInterpOverlay)))
+                if (bValue && !overlayMan.HasOverlay<NetInterpOverlay>())
                 {
                     overlayMan.AddOverlay(new NetInterpOverlay());
                     shell.WriteLine("Enabled network interp overlay.");
                 }
-                else if (overlayMan.HasOverlay(nameof(NetInterpOverlay)))
+                else if (overlayMan.HasOverlay<NetInterpOverlay>())
                 {
-                    overlayMan.RemoveOverlay(nameof(NetInterpOverlay));
+                    overlayMan.RemoveOverlay<NetInterpOverlay>();
                     shell.WriteLine("Disabled network interp overlay.");
                 }
             }

Robust.Client/Graphics/AtlasTexture.cs

@@ -1,4 +1,4 @@
-using JetBrains.Annotations;
+using JetBrains.Annotations;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 

Robust.Client/Graphics/Clyde/Clyde.HLR.cs

@@ -7,6 +7,8 @@ using Robust.Client.ResourceManagement;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
+using OpenToolkit.Graphics.OpenGL4;
+using Robust.Shared.Enums;
 
 namespace Robust.Client.Graphics.Clyde
 {
@@ -68,8 +70,7 @@ namespace Robust.Client.Graphics.Clyde
             RenderOverlays(OverlaySpace.ScreenSpaceBelowWorld);
 
             _mainViewport.Eye = _eyeManager.CurrentEye;
-            RenderViewport(_mainViewport);
-
+            RenderViewport(_mainViewport); //Worldspace overlays are rendered here.
             {
                 var handle = _renderHandle.DrawingHandleScreen;
                 var tex = _mainViewport.RenderTarget.Texture;
@@ -107,25 +108,67 @@ namespace Robust.Client.Graphics.Clyde
                         list.Add(overlay);
                     }
                 }
-
-                list.Sort(OverlayComparer.Instance);
-
-                foreach (var overlay in list)
-                {
-                    overlay.ClydeRender(_renderHandle, space);
-                }
-
                 FlushRenderQueue();
+                list.Sort(OverlayComparer.Instance);
+                foreach (var overlay in list) {
+                    if (overlay.RequestScreenTexture) {
+                        FlushRenderQueue();
+                        UpdateOverlayScreenTexture(space, _mainViewport.RenderTarget);
+                    }
+                    if (overlay.OverwriteTargetFrameBuffer()) {
+                        ClearFramebuffer(default);
+                    }
+                    overlay.ClydeRender(_renderHandle, space);
+                    FlushRenderQueue();
+                }
             }
         }
 
-        private void DrawEntitiesAndWorldOverlay(Viewport viewport, Box2 worldBounds)
+        private ClydeTexture? ScreenBufferTexture;
+        private GLHandle screenBufferHandle;
+        private Vector2 lastFrameSize;
+        /// <summary>
+        ///    Sends SCREEN_TEXTURE to all overlays in the given OverlaySpace that request it.
+        /// </summary>
+        private bool UpdateOverlayScreenTexture(OverlaySpace space, RenderTexture texture) {
+            //This currently does NOT consider viewports and just grabs the current screen framebuffer. This will need to be improved upon in the future.
+            List<Overlay> oTargets = new List<Overlay>();
+            foreach (var overlay in _overlayManager.AllOverlays) {
+                if (overlay.RequestScreenTexture && overlay.Space == space) {
+                    oTargets.Add(overlay);
+                }
+            }
+            if (oTargets.Count > 0 && ScreenBufferTexture != null) {
+                if (lastFrameSize != _framebufferSize) { 
+                    GL.BindTexture(TextureTarget.Texture2D, screenBufferHandle.Handle);
+                    GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Srgb8Alpha8, _framebufferSize.X, _framebufferSize.Y, 0,
+                        PixelFormat.Rgba, PixelType.UnsignedByte, IntPtr.Zero);
+                }
+                lastFrameSize = _framebufferSize;
+                CopyRenderTextureToTexture(texture, ScreenBufferTexture);
+                foreach (Overlay overlay in oTargets) {
+                    overlay.ScreenTexture = ScreenBufferTexture;
+                }
+                oTargets.Clear();
+                return true;
+            }
+            return false;
+        }
+
+
+
+
+
+
+        private void DrawEntities(Viewport viewport, Box2 worldBounds)
         {
             if (_eyeManager.CurrentMap == MapId.Nullspace || !_mapManager.HasMapEntity(_eyeManager.CurrentMap))
             {
                 return;
             }
 
+            RenderOverlays(OverlaySpace.WorldSpaceBelowEntities);
+
             var screenSize = viewport.Size;
 
             // So we could calculate the correct size of the entities based on the contents of their sprite...
@@ -267,14 +310,6 @@ namespace Robust.Client.Graphics.Clyde
 
             _drawingSpriteList.Clear();
             FlushRenderQueue();
-
-            // Cleanup remainders
-            foreach (var overlay in worldOverlays)
-            {
-                overlay.ClydeRender(_renderHandle, OverlaySpace.WorldSpace);
-            }
-
-            FlushRenderQueue();
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
@@ -368,12 +403,21 @@ namespace Robust.Client.Graphics.Clyde
                     // We will also render worldspace overlays here so we can do them under / above entities as necessary
                     using (DebugGroup("Entities"))
                     {
-                        DrawEntitiesAndWorldOverlay(viewport, worldBounds);
+                        DrawEntities(viewport, worldBounds);
                     }
 
+                    RenderOverlays(OverlaySpace.WorldSpaceBelowFOV);
+
                     if (_lightManager.Enabled && _lightManager.DrawHardFov && eye.DrawFov)
                     {
+                        GL.Clear(ClearBufferMask.StencilBufferBit);
+                        GL.Enable(EnableCap.StencilTest);
+                        GL.StencilOp(OpenToolkit.Graphics.OpenGL4.StencilOp.Keep, OpenToolkit.Graphics.OpenGL4.StencilOp.Keep, OpenToolkit.Graphics.OpenGL4.StencilOp.Replace);
+                        GL.StencilFunc(StencilFunction.Always, 1, 0xFF);
+                        GL.StencilMask(0xFF);
                         ApplyFovToBuffer(viewport, eye);
+                        GL.StencilMask(0x00);
+                        GL.Disable(EnableCap.StencilTest);
                     }
                 }
 
@@ -401,6 +445,14 @@ namespace Robust.Client.Graphics.Clyde
                         viewport.WallBleedIntermediateRenderTarget2.Texture,
                         UIBox2.FromDimensions(Vector2.Zero, ScreenSize), new Color(1, 1, 1, 0.5f));
                 }
+
+
+                RenderOverlays(OverlaySpace.WorldSpace);
+
+                GL.StencilFunc(StencilFunction.Notequal, 1, 0xFF);
+                GL.Disable(EnableCap.DepthTest);
+                RenderOverlays(OverlaySpace.WorldSpaceFOVStencil);
+                GL.Disable(EnableCap.StencilTest);
             }
 
             PopRenderStateFull(state);

Robust.Client/Graphics/Clyde/Clyde.Helpers.cs

@@ -5,6 +5,7 @@ using OpenToolkit.Graphics.OpenGL4;
 using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
+using SixLabors.ImageSharp.PixelFormats;
 using ES20 = OpenToolkit.Graphics.ES20;
 
 namespace Robust.Client.Graphics.Clyde
@@ -31,6 +32,27 @@ namespace Robust.Client.Graphics.Clyde
             CheckGlError();
             GL.BindTexture(TextureTarget.Texture2D, glHandle.Handle);
             CheckGlError();
+            GL.ActiveTexture(TextureUnit.Texture0);
+        }
+
+        private void CopyRenderTextureToTexture(RenderTexture source, ClydeTexture target) {
+            LoadedRenderTarget sourceLoaded = RtToLoaded(source);
+            bool pause = sourceLoaded != _currentBoundRenderTarget;
+            FullStoredRendererState? store = null;
+            if (pause) {
+                store = PushRenderStateFull();
+                BindRenderTargetFull(source);
+                CheckGlError();
+            }
+
+            GL.BindTexture(TextureTarget.Texture2D, _loadedTextures[target.TextureId].OpenGLObject.Handle);
+            CheckGlError();
+            GL.CopyTexSubImage2D(TextureTarget.Texture2D, 0, 0, 0, 0, 0, _framebufferSize.X, _framebufferSize.Y);
+            CheckGlError();
+
+            if (pause && store != null) {
+                PopRenderStateFull((FullStoredRendererState)store);
+            }
         }
 
         private static long EstPixelSize(PixelInternalFormat format)

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

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;

Robust.Client/Graphics/Clyde/Clyde.Rendering.cs

@@ -280,7 +280,7 @@ namespace Robust.Client.Graphics.Clyde
         }
 
         /// <summary>
-        ///     Flush the render handle, processing and re-pooling all the command lists.
+        ///     Flushes the render handle, processing and re-pooling all the command lists.
         /// </summary>
         private void FlushRenderQueue()
         {
@@ -371,6 +371,7 @@ namespace Robust.Client.Graphics.Clyde
 
             program.Use();
 
+            int textureUnitVal = 0;
             // Assign shader parameters to uniform since they may be dirty.
             foreach (var (name, value) in instance.Parameters)
             {
@@ -413,6 +414,15 @@ namespace Robust.Client.Graphics.Clyde
                     case Matrix4 matrix4:
                         program.SetUniform(name, matrix4);
                         break;
+                    case ClydeTexture clydeTexture:
+                        //It's important to start at Texture6 here since DrawCommandBatch uses Texture0 and Texture1 immediately after calling this
+                        //function! If passing in textures as uniforms ever stops working it might be since someone made it use all the way up to Texture6 too.
+                        //Might change this in the future?
+                        TextureUnit cTarget = TextureUnit.Texture6+textureUnitVal;
+                        SetTexture(cTarget, ((ClydeTexture)clydeTexture).TextureId);
+                        program.SetUniformTexture(name, cTarget);
+                        textureUnitVal++;
+                        break;
                     default:
                         throw new InvalidOperationException($"Unable to handle shader parameter {name}: {value}");
                 }

Robust.Client/Graphics/Clyde/Clyde.Shaders.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
@@ -428,7 +428,8 @@ namespace Robust.Client.Graphics.Clyde
 
             private protected override void SetParameterImpl(string name, Texture value)
             {
-                throw new NotImplementedException();
+                var data = Parent._shaderInstances[Handle];
+                data.Parameters[name] = value;
             }
 
             private protected override void SetStencilOpImpl(StencilOp op)

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

@@ -56,19 +56,19 @@ namespace Robust.Client.Graphics.Clyde
                 {
                     // Disable sRGB so stuff doesn't get interpreter wrong.
                     actualParams.Srgb = false;
-                    var img = ApplyA8Swizzle((Image<A8>) (object) image);
+                    using var img = ApplyA8Swizzle((Image<A8>) (object) image);
                     return LoadTextureFromImage(img, name, loadParams);
                 }
 
                 if (pixelType == typeof(L8) && !actualParams.Srgb)
                 {
-                    var img = ApplyL8Swizzle((Image<L8>) (object) image);
+                    using var img = ApplyL8Swizzle((Image<L8>) (object) image);
                     return LoadTextureFromImage(img, name, loadParams);
                 }
             }
 
             // Flip image because OpenGL reads images upside down.
-            var copy = FlipClone(image);
+            using var copy = FlipClone(image);
 
             var texture = CreateBaseTextureInternal<T>(image.Width, image.Height, actualParams, name);
 

Robust.Client/Graphics/Clyde/Clyde.cs

@@ -315,6 +315,11 @@ namespace Robust.Client.Graphics.Clyde
             UniformConstantsUBO = new GLUniformBuffer<UniformConstants>(this, BindingIndexUniformConstants, nameof(UniformConstantsUBO));
 
             CreateMainViewport();
+
+            screenBufferHandle = new GLHandle(GL.GenTexture());
+            GL.BindTexture(TextureTarget.Texture2D, screenBufferHandle.Handle);
+            ApplySampleParameters(TextureSampleParameters.Default);
+            ScreenBufferTexture = GenTexture(screenBufferHandle, _framebufferSize, true, null, TexturePixelType.Rgba32);
         }
 
         private void CreateMainViewport()

Robust.Client/Graphics/Clyde/GLObjects/Clyde.ShaderProgram.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using OpenToolkit.Graphics.OpenGL4;

Robust.Client/Graphics/Overlays/IOverlayManager.cs

@@ -1,22 +1,29 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using JetBrains.Annotations;
 using Robust.Shared.Timing;
 
 namespace Robust.Client.Graphics
 {
+
     [PublicAPI]
     public interface IOverlayManager
     {
-        void AddOverlay(Overlay overlay);
-        void RemoveOverlay(string id);
-        bool HasOverlay(string id);
+        bool AddOverlay(Overlay overlay);
 
-        Overlay GetOverlay(string id);
-        T GetOverlay<T>(string id) where T : Overlay;
+        bool RemoveOverlay(Overlay overlay);
+        bool RemoveOverlay(Type overlayClass);
+        bool RemoveOverlay<T>() where T : Overlay;
 
-        bool TryGetOverlay(string id, [NotNullWhen(true)] out Overlay? overlay);
-        bool TryGetOverlay<T>(string id, [NotNullWhen(true)] out T? overlay) where T : Overlay;
+        bool TryGetOverlay(Type overlayClass, out Overlay? overlay);
+        bool TryGetOverlay<T>(out T? overlay) where T : Overlay;
+
+        Overlay GetOverlay(Type overlayClass);
+        T GetOverlay<T>() where T : Overlay;
+
+        bool HasOverlay(Type overlayClass);
+        bool HasOverlay<T>() where T : Overlay;
 
         IEnumerable<Overlay> AllOverlays { get; }
     }

Robust.Client/Graphics/Overlays/Overlay.cs

@@ -1,65 +1,54 @@
-using System;
-using System.Collections.Generic;
-using JetBrains.Annotations;
 using Robust.Shared.IoC;
+using JetBrains.Annotations;
 using Robust.Shared.Timing;
+using Robust.Shared.Enums;
+using System;
 
 namespace Robust.Client.Graphics
 {
     /// <summary>
-    ///     An overlay is used for fullscreen drawing in the game, for example parallax.
+    ///     An overlay is used for fullscreen drawing in the game. This can range from drawing parallax to a full screen shader.
     /// </summary>
     [PublicAPI]
     public abstract class Overlay
     {
+
         /// <summary>
-        ///     The ID of this overlay. This is used to identify it inside the <see cref="IOverlayManager"/>.
+        ///     Determines when this overlay is drawn in the rendering queue.
         /// </summary>
-        public string ID { get; }
-
-        public virtual bool AlwaysDirty => false;
-        public bool IsDirty => AlwaysDirty || _isDirty;
-        public bool Drawing { get; private set; }
-
         public virtual OverlaySpace Space => OverlaySpace.ScreenSpace;
 
+        /// <summary>
+        ///     If set to true, <see cref="ScreenTexture"/> will be set to the current frame (at the moment before the overlay is rendered). This can be costly to performance, but
+        ///     some shaders will require it as a passed in uniform to operate.
+        /// </summary>
+        public virtual bool RequestScreenTexture => false;
+
+        /// <summary>
+        ///     If <see cref="RequestScreenTexture"> is true, then this will be set to the texture corresponding to the current frame. If false, it will always be null.
+        /// </summary>
+        public Texture? ScreenTexture = null;
+
+        /// <summary>
+        ///    Overlays on the same OverlaySpace will be drawn from lowest ZIndex to highest ZIndex. As an example, ZIndex -1 will be drawn before ZIndex 2.
+        ///    This value is 0 by default. Overlays with same ZIndex will be drawn in an random order.
+        /// </summary>
+        public int? ZIndex { get; set; }
+
         protected IOverlayManager OverlayManager { get; }
 
-        public int? ZIndex { get; set; }
+        private bool Disposed = false;
 
-        public virtual bool SubHandlesUseMainShader { get; } = true;
-
-        private bool _isDirty = true;
-
-        private readonly List<DrawingHandleBase> TempHandles = new();
-
-        private bool Disposed;
-
-        protected Overlay(string id)
+        public Overlay()
         {
             OverlayManager = IoCManager.Resolve<IOverlayManager>();
-            ID = id;
         }
 
-        public void Dispose()
-        {
-            if (Disposed)
-            {
-                return;
-            }
-
-            Dispose(true);
-            Disposed = true;
-            GC.SuppressFinalize(this);
-        }
-
-        ~Overlay()
-        {
-            Dispose(false);
-        }
-
-        protected virtual void Dispose(bool disposing)
-        {
+        /// <summary>
+        ///     If this function returns true, the target framebuffer will be wiped before applying this overlay to it.
+        /// </summary>
+        public virtual bool OverwriteTargetFrameBuffer(){
+            return false;
         }
 
         /// <summary>
@@ -69,50 +58,34 @@ namespace Robust.Client.Graphics
         /// <param name="currentSpace">Current space that is being drawn. This function is called for every space that was set up in initialization.</param>
         protected abstract void Draw(DrawingHandleBase handle, OverlaySpace currentSpace);
 
-        public void Dirty()
-        {
-            _isDirty = true;
+        protected internal virtual void FrameUpdate(FrameEventArgs args) { }
+
+        ~Overlay() {
+            Dispose();
+        }
+
+        public void Dispose() {
+            if (Disposed) 
+                return;
+            else
+                DisposeBehavior();
+        }
+
+        protected virtual void DisposeBehavior(){
+            Disposed = true;
+            GC.SuppressFinalize(this);
         }
 
-        protected internal virtual void FrameUpdate(FrameEventArgs args) { }
 
         internal void ClydeRender(IRenderHandle renderHandle, OverlaySpace currentSpace)
         {
             DrawingHandleBase handle;
-            if (currentSpace == OverlaySpace.WorldSpace)
-                handle = renderHandle.DrawingHandleWorld;
-            else
+            if (currentSpace == OverlaySpace.ScreenSpace || currentSpace == OverlaySpace.ScreenSpaceBelowWorld)
                 handle = renderHandle.DrawingHandleScreen;
+            else
+                handle = renderHandle.DrawingHandleWorld;
 
             Draw(handle, currentSpace);
         }
     }
-
-
-    /// <summary>
-    ///     Determines in which canvas layers an overlay gets drawn.
-    /// </summary>
-    [Flags]
-    public enum OverlaySpace : byte
-    {
-        /// <summary>
-        ///     Used for matching bit flags.
-        /// </summary>
-        None = 0b0000,
-
-        /// <summary>
-        ///     This overlay will be drawn in the UI root, thus being in screen space.
-        /// </summary>
-        ScreenSpace = 0b0001,
-
-        /// <summary>
-        ///     This overlay will be drawn in the world root, thus being in world space.
-        /// </summary>
-        WorldSpace = 0b0010,
-
-        /// <summary>
-        ///     Drawn in screen coordinates, but behind the world.
-        /// </summary>
-        ScreenSpaceBelowWorld = 0b0100,
-    }
 }

Robust.Client/Graphics/Overlays/OverlayManager.cs

@@ -1,13 +1,15 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using Robust.Shared.Log;
 using Robust.Shared.Timing;
 
 namespace Robust.Client.Graphics
 {
     internal class OverlayManager : IOverlayManagerInternal
     {
-        private readonly Dictionary<string, Overlay> _overlays = new();
+        private readonly Dictionary<Type, Overlay> _overlays = new Dictionary<Type, Overlay>();
+        public IEnumerable<Overlay> AllOverlays => _overlays.Values;
 
         public void FrameUpdate(FrameEventArgs args)
         {
@@ -17,59 +19,80 @@ namespace Robust.Client.Graphics
             }
         }
 
-        public void AddOverlay(Overlay overlay)
+        public bool AddOverlay(Overlay overlay)
         {
-            if (_overlays.ContainsKey(overlay.ID))
-            {
-                throw new InvalidOperationException($"We already have an overlay with ID '{overlay.ID}'");
+            if(_overlays.ContainsKey(overlay.GetType()))
+                return false;
+            _overlays.Add(overlay.GetType(), overlay);
+            return true;
+        }
+
+
+
+        public bool RemoveOverlay(Type overlayClass)
+        {
+            if(!overlayClass.IsSubclassOf(typeof(Overlay))){
+                Logger.Error("RemoveOverlay was called with arg: " + overlayClass.ToString() + ", which is not a subclass of Overlay!");
+                return false;
             }
-
-            _overlays.Add(overlay.ID, overlay);
+            return _overlays.Remove(overlayClass);
         }
 
-        public Overlay GetOverlay(string id)
-        {
-            return _overlays[id];
+        public bool RemoveOverlay<T>() where T : Overlay{
+            return RemoveOverlay(typeof(T));
         }
 
-        public T GetOverlay<T>(string id) where T : Overlay
-        {
-            return (T) GetOverlay(id);
+        public bool RemoveOverlay(Overlay overlay) {
+            return _overlays.Remove(overlay.GetType());
         }
 
-        public bool HasOverlay(string id)
-        {
-            return _overlays.ContainsKey(id);
-        }
 
-        public void RemoveOverlay(string id)
+
+
+
+        public bool TryGetOverlay(Type overlayClass, [NotNullWhen(true)] out Overlay? overlay)
         {
-            if (!_overlays.TryGetValue(id, out var overlay))
-            {
-                return;
+            overlay = null;
+            if (!overlayClass.IsSubclassOf(typeof(Overlay))){
+                Logger.Error("TryGetOverlay was called with arg: " + overlayClass.ToString() + ", which is not a subclass of Overlay!");
+                return false;
             }
-
-            overlay.Dispose();
-            _overlays.Remove(id);
+            return _overlays.TryGetValue(overlayClass, out overlay);
         }
 
-        public bool TryGetOverlay(string id, [NotNullWhen(true)] out Overlay? overlay)
-        {
-            return _overlays.TryGetValue(id, out overlay);
-        }
-
-        public bool TryGetOverlay<T>(string id, [NotNullWhen(true)] out T? overlay) where T : Overlay
-        {
-            if (_overlays.TryGetValue(id, out var value))
-            {
-                overlay = (T) value;
+        public bool TryGetOverlay<T>([NotNullWhen(true)] out T? overlay) where T : Overlay {
+            overlay = null;
+            if(_overlays.TryGetValue(typeof(T), out Overlay? toReturn)){
+                overlay = (T)toReturn;
                 return true;
             }
-
-            overlay = default;
             return false;
         }
 
-        public IEnumerable<Overlay> AllOverlays => _overlays.Values;
+
+
+
+        public Overlay GetOverlay(Type overlayClass) {
+            return _overlays[overlayClass];
+        }
+
+        public T GetOverlay<T>() where T : Overlay {
+            return (T)_overlays[typeof(T)];
+        }
+
+
+
+
+
+        public bool HasOverlay(Type overlayClass) {
+            if (!overlayClass.IsSubclassOf(typeof(Overlay)))
+                Logger.Error("HasOverlay was called with arg: " + overlayClass.ToString() + ", which is not a subclass of Overlay!");
+            return _overlays.Remove(overlayClass);
+        }
+
+        public bool HasOverlay<T>() where T : Overlay  {
+            return _overlays.Remove(typeof(T));
+        }
+
     }
 }

Robust.Client/Graphics/RSI/RSI.State.cs

@@ -19,10 +19,10 @@ namespace Robust.Client.Graphics
         public sealed class State : IRsiStateLike
         {
             // List of delays for the frame to reach the next frame.
-            private readonly float[] Delays;
+            public readonly float[] Delays;
 
             // 2D array for the texture to use for each animation frame at each direction.
-            private readonly Texture[][] Icons;
+            public readonly Texture[][] Icons;
 
             internal State(Vector2i size, StateId stateId, DirectionType direction, float[] delays, Texture[][] icons)
             {

Robust.Client/Graphics/RSI/RSISchema.json

@@ -1,47 +0,0 @@
-{
-    "$schema": "http://json-schema.org/draft-04/schema#",
-    "title": "RSI Image Format Validation Schema V1",
-    "description": "Robust Station Image",
-    "type": "object",
-    "definitions": {
-        "size": {
-            "type": "object",
-            "properties": {
-                "x": {"type": "integer", "minimum": 1},
-                "y": {"type": "integer", "minimum": 1}
-            },
-            "required": ["x","y"]
-        },
-        "directions": {
-            "type": "integer",
-            "enum": [1,4,8]
-        },
-        "state": {
-            "type": "object",
-            "properties": {
-                "name": {"type": "string"},
-                "flags": {"type": "object"}, //To be de-serialized as a Dictionary
-                "directions": {"$ref": "#/definitions/directions"},
-                "delays": {
-                    "type": "array",
-                    "minItems": 1,
-                    "items": {
-                        "type": "array",
-                        "items": {"type": "number", "minimum": 0, "exclusiveMinimum": true} //number == float
-                    }
-                }
-            },
-            "required": ["name"] //'delays' is marked as optional in the spec
-        }
-    },
-    "properties": {
-        "version": {"type": "integer", "minimum": 1, "maximum": 1},
-        "size": {"$ref": "#/definitions/size"},
-        "states": {
-            "type": "array",
-            "items": {"$ref": "#/definitions/state"},
-            "minItems": 1
-        }
-    },
-    "required": ["version","size","states"]
-}

Robust.Client/Physics/DebugPhysicsIslandSystem.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using Robust.Client.Graphics;
 using Robust.Shared.Console;
+using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
@@ -67,7 +68,7 @@ namespace Robust.Client.Physics
         public override void Shutdown()
         {
             base.Shutdown();
-            IoCManager.Resolve<IOverlayManager>().RemoveOverlay(nameof(PhysicsIslandOverlay));
+            IoCManager.Resolve<IOverlayManager>().RemoveOverlay(typeof(PhysicsIslandOverlay));
         }
 
         private void HandleIslandSolveMessage(IslandSolveMessage message)
@@ -94,7 +95,7 @@ namespace Robust.Client.Physics
 
         public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-        public PhysicsIslandOverlay() : base(nameof(PhysicsIslandOverlay))
+        public PhysicsIslandOverlay()
         {
             _islandSystem = EntitySystem.Get<DebugPhysicsIslandSystem>();
             _eyeManager = IoCManager.Resolve<IEyeManager>();

Robust.Client/Placement/PlacementOverlay.cs

@@ -1,5 +1,7 @@
+using Robust.Shared.Enums;
 using Robust.Client.Graphics;
 
+
 namespace Robust.Client.Placement
 {
     public partial class PlacementManager
@@ -7,10 +9,9 @@ namespace Robust.Client.Placement
         internal class PlacementOverlay : Overlay
         {
             private readonly PlacementManager _manager;
-            public override bool AlwaysDirty => true;
             public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-            public PlacementOverlay(PlacementManager manager) : base("placement")
+            public PlacementOverlay(PlacementManager manager)
             {
                 _manager = manager;
                 ZIndex = 100;

Robust.Client/ResourceManagement/ResourceTypes/RSIResource.cs

@@ -2,17 +2,12 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Reflection;
+using System.Text.Json;
+using JetBrains.Annotations;
 using Robust.Client.Graphics;
 using Robust.Client.Utility;
-using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
-
-using Newtonsoft.Json.Linq;
-#if DEBUG
-using NJsonSchema;
-#endif
 using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -24,6 +19,14 @@ namespace Robust.Client.ResourceManagement
     /// </summary>
     public sealed class RSIResource : BaseResource
     {
+        private static readonly float[] OneArray = {1};
+
+        private static readonly JsonSerializerOptions SerializerOptions =
+            new JsonSerializerOptions(JsonSerializerDefaults.Web)
+            {
+                AllowTrailingCommas = true
+            };
+
         public RSI RSI { get; private set; } = default!;
 
         /// <summary>
@@ -38,64 +41,36 @@ namespace Robust.Client.ResourceManagement
 
         public override void Load(IResourceCache cache, ResourcePath path)
         {
-            var manifestPath = path / "meta.json";
-            string manifestContents;
+            var metadata = LoadRsiMetadata(cache, path);
 
-            using (var manifestFile = cache.ContentFileRead(manifestPath))
-            using (var reader = new StreamReader(manifestFile))
-            {
-                manifestContents = reader.ReadToEnd();
-            }
+            var stateCount = metadata.States.Length;
+            var toAtlas = new StateReg[stateCount];
 
-#if DEBUG
-            if (RSISchema != null)
-            {
-                var errors = RSISchema.Validate(manifestContents);
-                if (errors.Count != 0)
-                {
-                    Logger.Error($"Unable to load RSI from '{path}', {errors.Count} errors:");
-
-                    foreach (var error in errors)
-                    {
-                        Logger.Error("{0}", error.ToString());
-                    }
-
-                    throw new RSILoadException($"{errors.Count} errors while loading RSI. See console.");
-                }
-            }
-#endif
-
-            // Ok schema validated just fine.
-            var manifestJson = JObject.Parse(manifestContents);
-
-            var toAtlas = new List<(Image<Rgba32> src, Texture[][] output, int[][] indices, Vector2i[][] offsets, int totalFrameCount)>();
-
-            var metaData = ParseMetaData(manifestJson);
-            var frameSize = metaData.Size;
+            var frameSize = metadata.Size;
             var rsi = new RSI(frameSize, path);
 
-            var callbackOffsets = new Dictionary<RSI.StateId, Vector2i[][]>();
+            var callbackOffsets = new Dictionary<RSI.StateId, Vector2i[][]>(stateCount);
 
             // Do every state.
-            foreach (var stateObject in metaData.States)
+            for (var index = 0; index < metadata.States.Length; index++)
             {
+                ref var reg = ref toAtlas[index];
+
+                var stateObject = metadata.States[index];
                 // Load image from disk.
                 var texPath = path / (stateObject.StateId + ".png");
-                var stream = cache.ContentFileRead(texPath);
-                Image<Rgba32> image;
-                using (stream)
+                using (var stream = cache.ContentFileRead(texPath))
                 {
-                    image = Image.Load<Rgba32>(stream);
+                    reg.Src = Image.Load<Rgba32>(stream);
                 }
-                var sheetSize = new Vector2i(image.Width, image.Height);
 
-                if (sheetSize.X % frameSize.X != 0 || sheetSize.Y % frameSize.Y != 0)
+                if (reg.Src.Width % frameSize.X != 0 || reg.Src.Height % frameSize.Y != 0)
                 {
                     throw new RSILoadException("State image size is not a multiple of the icon size.");
                 }
 
                 // Load all frames into a list so we can operate on it more sanely.
-                var frameCount = stateObject.Delays.Sum(delayList => delayList.Length);
+                reg.TotalFrameCount = stateObject.Delays.Sum(delayList => delayList.Length);
 
                 var (foldedDelays, foldedIndices) = FoldDelays(stateObject.Delays);
 
@@ -108,15 +83,18 @@ namespace Robust.Client.ResourceManagement
                     callbackOffset[i] = new Vector2i[foldedIndices[0].Length];
                 }
 
+                reg.Output = textures;
+                reg.Indices = foldedIndices;
+                reg.Offsets = callbackOffset;
+
                 var state = new RSI.State(frameSize, stateObject.StateId, stateObject.DirType, foldedDelays, textures);
                 rsi.AddState(state);
 
-                toAtlas.Add((image, textures, foldedIndices, callbackOffset, frameCount));
                 callbackOffsets[stateObject.StateId] = callbackOffset;
             }
 
             // Poorly hacked in texture atlas support here.
-            var totalFrameCount = toAtlas.Sum(p => p.totalFrameCount);
+            var totalFrameCount = toAtlas.Sum(p => p.TotalFrameCount);
 
             // Generate atlas.
             var dimensionX = (int) MathF.Ceiling(MathF.Sqrt(totalFrameCount));
@@ -125,12 +103,13 @@ namespace Robust.Client.ResourceManagement
             using var sheet = new Image<Rgba32>(dimensionX * frameSize.X, dimensionY * frameSize.Y);
 
             var sheetIndex = 0;
-            foreach (var (src, _, _, _, frameCount) in toAtlas)
+            for (var index = 0; index < toAtlas.Length; index++)
             {
+                ref var reg = ref toAtlas[index];
                 // Blit all the frames over.
-                for (var i = 0; i < frameCount; i++)
+                for (var i = 0; i < reg.TotalFrameCount; i++)
                 {
-                    var srcWidth = (src.Width / frameSize.X);
+                    var srcWidth = (reg.Src.Width / frameSize.X);
                     var srcColumn = i % srcWidth;
                     var srcRow = i / srcWidth;
                     var srcPos = (srcColumn * frameSize.X, srcRow * frameSize.Y);
@@ -141,23 +120,24 @@ namespace Robust.Client.ResourceManagement
 
                     var srcBox = UIBox2i.FromDimensions(srcPos, frameSize);
 
-                    src.Blit(srcBox, sheet, sheetPos);
+                    reg.Src.Blit(srcBox, sheet, sheetPos);
                 }
 
-                sheetIndex += frameCount;
+                sheetIndex += reg.TotalFrameCount;
             }
 
             // Load atlas.
             var texture = Texture.LoadFromImage(sheet, path.ToString());
 
             var sheetOffset = 0;
-            foreach (var (_, output, indices, offsets, frameCount) in toAtlas)
+            for (var toAtlasIndex = 0; toAtlasIndex < toAtlas.Length; toAtlasIndex++)
             {
-                for (var i = 0; i < indices.Length; i++)
+                ref var reg = ref toAtlas[toAtlasIndex];
+                for (var i = 0; i < reg.Indices.Length; i++)
                 {
-                    var dirIndices = indices[i];
-                    var dirOutput = output[i];
-                    var dirOffsets = offsets[i];
+                    var dirIndices = reg.Indices[i];
+                    var dirOutput = reg.Output[i];
+                    var dirOffsets = reg.Offsets[i];
 
                     for (var j = 0; j < dirIndices.Length; j++)
                     {
@@ -172,12 +152,13 @@ namespace Robust.Client.ResourceManagement
                     }
                 }
 
-                sheetOffset += frameCount;
+                sheetOffset += reg.TotalFrameCount;
             }
 
-            foreach (var (image, _, _, _, _) in toAtlas)
+            for (var i = 0; i < toAtlas.Length; i++)
             {
-                image.Dispose();
+                ref var reg = ref toAtlas[i];
+                reg.Src.Dispose();
             }
 
             RSI = rsi;
@@ -188,6 +169,90 @@ namespace Robust.Client.ResourceManagement
             }
         }
 
+        private static RsiMetadata LoadRsiMetadata(IResourceCache cache, ResourcePath path)
+        {
+            var manifestPath = path / "meta.json";
+            string manifestContents;
+
+            using (var manifestFile = cache.ContentFileRead(manifestPath))
+            using (var reader = new StreamReader(manifestFile))
+            {
+                manifestContents = reader.ReadToEnd();
+            }
+
+            // Ok schema validated just fine.
+            var manifestJson = JsonSerializer.Deserialize<RsiJsonMetadata>(manifestContents, SerializerOptions);
+
+            if (manifestJson == null)
+                throw new RSILoadException("Manifest JSON was null!");
+
+            var size = manifestJson.Size;
+            var states = new StateMetadata[manifestJson.States.Length];
+
+            for (var stateI = 0; stateI < manifestJson.States.Length; stateI++)
+            {
+                var stateObject = manifestJson.States[stateI];
+                var stateName = stateObject.Name;
+                RSI.State.DirectionType directions;
+                int dirValue;
+
+                if (stateObject.Directions is { } dirVal)
+                {
+                    dirValue = dirVal;
+                    directions = dirVal 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!
+
+                // Get the lists of delays.
+                float[][] delays;
+                if (stateObject.Delays != null)
+                {
+                    delays = stateObject.Delays;
+
+                    if (delays.Length != dirValue)
+                    {
+                        throw new RSILoadException(
+                            "DirectionsdirectionFramesList count does not match amount of delays specified.");
+                    }
+
+                    for (var i = 0; i < delays.Length; i++)
+                    {
+                        var delayList = delays[i];
+                        if (delayList.Length == 0)
+                        {
+                            delays[i] = OneArray;
+                        }
+                    }
+                }
+                else
+                {
+                    delays = new float[dirValue][];
+                    // No delays specified, default to 1 frame per dir.
+                    for (var i = 0; i < dirValue; i++)
+                    {
+                        delays[i] = OneArray;
+                    }
+                }
+
+                states[stateI] = new StateMetadata(new RSI.StateId(stateName), directions, delays);
+            }
+
+            return new RsiMetadata(size, states);
+        }
+
         /// <summary>
         ///     Folds a per-directional sets of animation delays
         ///     into an equivalent set of animation delays and indices that works for every direction.
@@ -336,109 +401,25 @@ namespace Robust.Client.ResourceManagement
             return (floatDelays, arrayIndices);
         }
 
-        internal static RsiMetadata ParseMetaData(JObject manifestJson)
+        private struct StateReg
         {
-            var size = manifestJson["size"]!.ToObject<Vector2i>();
-            var states = new List<StateMetadata>();
-
-            foreach (var stateObject in manifestJson["states"]!.Cast<JObject>())
-            {
-                var stateName = stateObject["name"]!.ToObject<string>()!;
-                RSI.State.DirectionType directions;
-                int dirValue;
-
-                if (stateObject.TryGetValue("directions", out var dirJToken))
-                {
-                    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!
-
-                // Get the lists of delays.
-                float[][] delays;
-                if (stateObject.TryGetValue("delays", out var delayToken))
-                {
-                    delays = delayToken.ToObject<float[][]>()!;
-
-                    if (delays.Length != dirValue)
-                    {
-                        throw new RSILoadException(
-                            "DirectionsdirectionFramesList count does not match amount of delays specified.");
-                    }
-
-                    for (var i = 0; i < delays.Length; i++)
-                    {
-                        var delayList = delays[i];
-                        if (delayList.Length == 0)
-                        {
-                            delays[i] = new float[] {1};
-                        }
-                    }
-                }
-                else
-                {
-                    delays = new float[dirValue][];
-                    // No delays specified, default to 1 frame per dir.
-                    for (var i = 0; i < dirValue; i++)
-                    {
-                        delays[i] = new float[] {1};
-                    }
-                }
-
-                states.Add(new StateMetadata(new RSI.StateId(stateName), directions, delays));
-            }
-
-            return new RsiMetadata(size, states);
+            public Image<Rgba32> Src;
+            public Texture[][] Output;
+            public int[][] Indices;
+            public Vector2i[][] Offsets;
+            public int TotalFrameCount;
         }
 
-#if DEBUG
-        private static readonly JsonSchema? RSISchema = GetSchema();
-
-        private static JsonSchema? GetSchema()
-        {
-            try
-            {
-                string schema;
-                using (var schemaStream = Assembly.GetExecutingAssembly()
-                    .GetManifestResourceStream("Robust.Client.Graphics.RSI.RSISchema.json")!)
-                using (var schemaReader = new StreamReader(schemaStream))
-                {
-                    schema = schemaReader.ReadToEnd();
-                }
-
-                return JsonSchema.FromJsonAsync(schema).Result;
-            }
-            catch (Exception e)
-            {
-                System.Console.WriteLine("Failed to load RSI JSON Schema!\n{0}", e);
-                return null;
-            }
-        }
-#endif
-
         internal sealed class RsiMetadata
         {
-            public RsiMetadata(Vector2i size, List<StateMetadata> states)
+            public RsiMetadata(Vector2i size, StateMetadata[] states)
             {
                 Size = size;
                 States = states;
             }
 
             public Vector2i Size { get; }
-            public List<StateMetadata> States { get; }
+            public StateMetadata[] States { get; }
         }
 
         internal sealed class StateMetadata
@@ -466,6 +447,17 @@ namespace Robust.Client.ResourceManagement
 
             public float[][] Delays { get; }
         }
+
+        // To be directly deserialized.
+        [UsedImplicitly]
+        private sealed record RsiJsonMetadata(Vector2i Size, StateJsonMetadata[] States)
+        {
+        }
+
+        [UsedImplicitly]
+        private sealed record StateJsonMetadata(string Name, int? Directions, float[][]? Delays)
+        {
+        }
     }
 
     [Serializable]

Robust.Client/Robust.Client.csproj

@@ -14,7 +14,6 @@
     <PackageReference Include="DiscordRichPresence" Version="1.0.175" />
     <PackageReference Include="JetBrains.Annotations" Version="2020.3.0" PrivateAssets="All" />
     <PackageReference Include="nfluidsynth" Version="0.3.1" />
-    <PackageReference Include="NJsonSchema" Version="10.3.8" />
     <PackageReference Include="NVorbis" Version="0.10.1" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
     <PackageReference Include="SixLabors.ImageSharp" Version="1.0.3" />
@@ -39,9 +38,6 @@
     <ProjectReference Include="..\Robust.Shared\Robust.Shared.csproj" />
   </ItemGroup>
   <ItemGroup>
-    <EmbeddedResource Include="Graphics\RSI\RSISchema.json" Condition="'$(Configuration)' == 'Debug'">
-      <LogicalName>Robust.Client.Graphics.RSI.RSISchema.json</LogicalName>
-    </EmbeddedResource>
 
     <EmbeddedResource Include="Graphics\Clyde\Shaders\*" />
   </ItemGroup>

Robust.Client/UserInterface/CustomControls/EntitySpawnWindow.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
@@ -67,6 +67,7 @@ namespace Robust.Client.UserInterface.CustomControls
 
             Title = Loc.GetString("Entity Spawn Panel");
 
+
             SetSize = (250, 300);
             MinSize = (250, 200);
 

Robust.Client/Utility/ImageSharpExt.cs

@@ -42,19 +42,20 @@ namespace Robust.Client.Utility
         {
             var dstSpan = destination.GetPixelSpan();
             var dstWidth = destination.Width;
+            var srcHeight = sourceRect.Height;
+            var srcWidth = sourceRect.Width;
 
             var (ox, oy) = destinationOffset;
 
-            for (var y = 0; y < sourceRect.Height; y++)
+            for (var y = 0; y < srcHeight; y++)
             {
                 var sourceRowOffset = sourceWidth * (y + sourceRect.Top) + sourceRect.Left;
                 var destRowOffset = dstWidth * (y + oy) + ox;
 
-                for (var x = 0; x < sourceRect.Width; x++)
-                {
-                    var pixel = source[x + sourceRowOffset];
-                    dstSpan[x + destRowOffset] = pixel;
-                }
+                var srcRow = source[sourceRowOffset..(sourceRowOffset + srcWidth)];
+                var dstRow = dstSpan[destRowOffset..(destRowOffset + srcWidth)];
+
+                srcRow.CopyTo(dstRow);
             }
         }
 

Robust.Client/Utility/SpriteSpecifierExt.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using Robust.Client.GameObjects;
 using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
@@ -41,6 +41,40 @@ namespace Robust.Client.Utility
             return specifier.RsiStateLike().Default;
         }
 
+        public static float[] FrameDelays(this SpriteSpecifier specifier) {
+            var resc = IoCManager.Resolve<IResourceCache>();
+            switch (specifier) {
+                case SpriteSpecifier.Rsi rsi:
+                    if (resc.TryGetResource<RSIResource>(SpriteComponent.TextureRoot / rsi.RsiPath, out var theRsi)) {
+                        if (theRsi.RSI.TryGetState(rsi.RsiState, out var state)) {
+                            return state.Delays;
+                        }
+                    }
+                    Logger.Error("Failed to load RSI {0}", rsi.RsiPath);
+                    return new float[0];
+
+                default:
+                    throw new NotImplementedException();
+            }
+        }
+
+        public static Texture[] FrameArr(this SpriteSpecifier specifier) {
+            var resc = IoCManager.Resolve<IResourceCache>();
+            switch (specifier) {
+                case SpriteSpecifier.Rsi rsi:
+                    if (resc.TryGetResource<RSIResource>(SpriteComponent.TextureRoot / rsi.RsiPath, out var theRsi)) {
+                        if (theRsi.RSI.TryGetState(rsi.RsiState, out var state)) {
+                            return state.Icons[0];
+                        }
+                    }
+                    Logger.Error("Failed to load RSI {0}", rsi.RsiPath);
+                    return new Texture[0];
+
+                default:
+                    throw new NotImplementedException();
+            }
+        }
+
         public static IDirectionalTextureProvider DirFrame0(this SpriteSpecifier specifier)
         {
             return specifier.RsiStateLike();

Robust.Shared.Maths/Vector2i.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
+using System.Text.Json.Serialization;
 using Newtonsoft.Json;
 
 namespace Robust.Shared.Maths
@@ -16,12 +17,12 @@ namespace Robust.Shared.Maths
         /// <summary>
         /// The X component of the Vector2i.
         /// </summary>
-        public int X;
+        [JsonInclude] public int X;
 
         /// <summary>
         /// The Y component of the Vector2i.
         /// </summary>
-        public int Y;
+        [JsonInclude] public int Y;
 
         /// <summary>
         /// Construct a vector from its coordinates.

Robust.Shared.Maths/Vector2u.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
+using System.Text.Json.Serialization;
 using Newtonsoft.Json;
 
 namespace Robust.Shared.Maths
@@ -12,12 +13,12 @@ namespace Robust.Shared.Maths
         /// <summary>
         /// The X component of the Vector2i.
         /// </summary>
-        public uint X;
+        [JsonInclude] public uint X;
 
         /// <summary>
         /// The Y component of the Vector2i.
         /// </summary>
-        public uint Y;
+        [JsonInclude] public uint Y;
 
         /// <summary>
         /// Construct a vector from its coordinates.

Robust.Shared/CVars.cs

@@ -372,8 +372,9 @@ namespace Robust.Shared
 
         // - Maximums
         // Squared
+        // 35 m/s, AKA half a tile per frame allowed. Divide this by frametime to get units per second.
         public static readonly CVarDef<float> MaxLinVelocity =
-            CVarDef.Create("physics.maxlinvelocity", 4.0f);
+            CVarDef.Create("physics.maxlinvelocity", 0.56f);
 
         // Squared
         public static readonly CVarDef<float> MaxAngVelocity =

Robust.Shared/Enums/OverlaySpaces.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Robust.Shared.Enums {
+    /// <summary>
+    ///     Determines in which canvas layers an overlay gets drawn.
+    /// </summary>
+    [Flags]
+    public enum OverlaySpace {
+        /// <summary>
+        ///     Used for matching bit flags.
+        /// </summary>
+        None = 0b000000,
+
+        /// <summary>
+        ///     This overlay will be drawn in screen coordinates in the UI space above the world.
+        /// </summary>
+        ScreenSpace = 0b000001,
+
+        /// <summary>
+        ///     This overlay will be drawn directly above normal worldspace, but a stencil equivalent to the FOV will be applied.
+        ///     You likely want to use <see cref="WorldSpaceBelowFOV"/>. This space should only be used if you fully understand why you need this.
+        /// </summary>
+        WorldSpaceFOVStencil = 0b000010,
+
+        /// <summary>
+        ///     This overlay will be drawn above entities, lighting, and FOV.
+        /// </summary>
+        WorldSpace = 0b000100,
+
+        /// <summary>
+        ///     This overlay will be drawn beneath FOV; above lighting and entities.
+        /// </summary>
+        WorldSpaceBelowFOV = 0b001000,
+
+        /// <summary>
+        ///     This overlay will be drawn beneath entities, lighting, and FOV; above grids.
+        /// </summary>
+        WorldSpaceBelowEntities = 0b010000,
+
+        /// <summary>
+        ///     This overlay will be drawn in screen coordinates behind the world. 
+        /// </summary>
+        ScreenSpaceBelowWorld = 0b100000,
+    }
+}

Robust.Shared/GameObjects/Components/Collidable/PhysicsComponent.Physics.cs

@@ -102,6 +102,7 @@ namespace Robust.Shared.GameObjects
                 if (_bodyType == value)
                     return;
 
+                var oldAnchored = _bodyType == BodyType.Static;
                 _bodyType = value;
 
                 ResetMassData();
@@ -120,8 +121,7 @@ namespace Robust.Shared.GameObjects
 
                 RegenerateContacts();
 
-                var oldAnchored = _bodyType == BodyType.Static;
-                var anchored = _bodyType == BodyType.Static;
+                var anchored = value == BodyType.Static;
 
                 if (oldAnchored != anchored)
                 {

Robust.Shared/GameObjects/Components/Transform/TransformComponent.cs

@@ -241,7 +241,7 @@ namespace Robust.Shared.GameObjects
             {
                 if (!_parent.IsValid())
                 {
-                    DebugTools.Assert("Tried to move root node.");
+                    DebugTools.Assert("Parent is invalid while attempting to set WorldPosition - did you try to move root node?");
                     return;
                 }
 

Robust.Shared/Physics/Dynamics/PhysicsMap.cs

@@ -531,11 +531,13 @@ namespace Robust.Shared.Physics.Dynamics
                     var body = _stack[--stackCount];
                     _island.Add(body);
                     _islandSet.Add(body);
-                    body.Awake = true;
 
                     // Static bodies don't propagate islands
                     if (body.BodyType == BodyType.Static) continue;
 
+                    // As static bodies can never be awake (unlike Farseer) we'll set this after the check.
+                    body.Awake = true;
+
                     for (var contactEdge = body.ContactEdges; contactEdge != null; contactEdge = contactEdge.Next)
                     {
                         var contact = contactEdge.Contact!;