Basic shitty grid background for map editor viewports

Robust.Client/MapEditor/GridBackgroundOverlay.cs

@@ -0,0 +1,47 @@
+ using System.Collections.Generic;
+using System.Numerics;
+using Robust.Client.Graphics;
+using Robust.Shared.Enums;
+using Robust.Shared.Maths;
+
+namespace Robust.Client.MapEditor;
+
+internal sealed class GridBackgroundOverlay : Overlay
+{
+    public readonly Dictionary<long, Parameters> ViewportParameters = new();
+
+    public override OverlaySpace Space => OverlaySpace.WorldSpaceBelowWorld;
+
+    protected internal override void Draw(in OverlayDrawArgs args)
+    {
+        if (!ViewportParameters.TryGetValue(args.Viewport.Id, out var parameters))
+            return;
+
+        // TODO: This sucks and should just cover the entire WorldAABB.
+        // Also, line thickness probably needs accounting for. Probably needs to become a screen-space overlay?
+        for (var x = -128; x < 128; x += 8)
+        {
+            var color = parameters.Color;
+            if (x == 0)
+                color = parameters.YAxisColor;
+
+            args.WorldHandle.DrawLine(new Vector2(x, -128), new Vector2(x, 128), color);
+        }
+
+        for (var y = -128; y < 128; y += 8)
+        {
+            var color = parameters.Color;
+            if (y == 0)
+                color = parameters.XAxisColor;
+
+            args.WorldHandle.DrawLine(new Vector2(-128, y), new Vector2(128, y), color);
+        }
+    }
+
+    public sealed class Parameters
+    {
+        public Color Color = Color.FromHex("#222");
+        public Color XAxisColor = Color.FromHex("#A22");
+        public Color YAxisColor = Color.FromHex("#2A2");
+    }
+}

Robust.Client/MapEditor/Interface/Panels/Helpers/MapViewportContainer.cs

@@ -4,12 +4,15 @@ using Robust.Client.Graphics;
 using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.CustomControls;
 using Robust.Shared.Graphics;
+using Robust.Shared.IoC;
 using Robust.Shared.Timing;
 
 namespace Robust.Client.MapEditor.Interface.Panels.Helpers;
 
 internal sealed class MapViewportContainer : ViewportContainer
 {
+    [Dependency] private readonly IOverlayManager _overlayManager = null!;
+
     private Vector2? _dragStartPos;
     private Vector2 _dragStartWorldPos;
 
@@ -17,8 +20,12 @@ internal sealed class MapViewportContainer : ViewportContainer
 
     public event Action<Vector2>? WorldPosChanged;
 
+    private readonly GridBackgroundOverlay.Parameters _gridParameters = new();
+
     public MapViewportContainer()
     {
+        IoCManager.InjectDependencies(this);
+
         MouseFilter = MouseFilterMode.Stop;
     }
 
@@ -70,4 +77,20 @@ internal sealed class MapViewportContainer : ViewportContainer
         if (Viewport != null)
             Viewport.Eye = Eye;
     }
+
+    protected override void Resized()
+    {
+        // TODO: The way this state is managed sucks. Wish I could set overlays on a per-viewport basis sanely.
+        if (Viewport != null && _overlayManager.TryGetOverlay(out GridBackgroundOverlay? bg))
+        {
+            bg.ViewportParameters.Remove(Viewport.Id);
+        }
+
+        base.Resized();
+
+        if (Viewport != null && _overlayManager.TryGetOverlay(out bg))
+        {
+            bg.ViewportParameters[Viewport.Id] = _gridParameters;
+        }
+    }
 }

Robust.Client/MapEditor/MapEditorState.cs

@@ -1,4 +1,5 @@
-using Robust.Client.Input;
+using Robust.Client.Graphics;
+using Robust.Client.Input;
 using Robust.Client.MapEditor.Interface;
 using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
@@ -14,6 +15,9 @@ internal sealed class MapEditorState : State.State
     [Dependency] private readonly IUserInterfaceManager _uiManager = null!;
     [Dependency] private readonly IEntitySystemManager _entitySystem = null!;
     [Dependency] private readonly IInputManager _inputManager = null!;
+    [Dependency] private readonly IOverlayManager _overlayManager = null!;
+
+    private readonly GridBackgroundOverlay _gridBackground = new();
 
     private readonly MapEditorMain _main;
 
@@ -30,10 +34,14 @@ internal sealed class MapEditorState : State.State
         LayoutContainer.SetAnchorAndMarginPreset(_main, LayoutContainer.LayoutPreset.Wide);
 
         _inputManager.Contexts.SetActiveContext(MapEditorInputContext.ContextName);
+
+        _overlayManager.AddOverlay(_gridBackground);
     }
 
     protected override void Shutdown()
     {
+        _overlayManager.RemoveOverlay<GridBackgroundOverlay>();
+
         _main.Orphan();
         _main.Shutdown();
     }