Add IPostProcessWorldShader for custom effect render passes.

OpenRA.Game/Graphics/PlatformInterfaces.cs

@@ -157,6 +157,7 @@ namespace OpenRA
 	{
 		void SetData(byte[] colors, int width, int height);
 		void SetFloatData(float[] data, int width, int height);
+		void SetDataFromReadBuffer(Rectangle rect);
 		byte[] GetData();
 		Size Size { get; }
 		TextureScaleFilter ScaleFilter { get; set; }

OpenRA.Game/Graphics/RenderPostProcessPassVertex.cs

@@ -0,0 +1,37 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System.Runtime.InteropServices;
+
+namespace OpenRA.Graphics
+{
+	[StructLayout(LayoutKind.Sequential)]
+	public readonly struct RenderPostProcessPassVertex
+	{
+		public readonly float X, Y;
+
+		public RenderPostProcessPassVertex(float x, float y)
+		{
+			X = x; Y = y;
+		}
+	}
+
+	public sealed class RenderPostProcessPassShaderBindings : ShaderBindings
+	{
+		public RenderPostProcessPassShaderBindings(string name)
+			: base("postprocess", "postprocess_" + name) { }
+
+		public override ShaderVertexAttribute[] Attributes { get; } = new[]
+		{
+			new ShaderVertexAttribute("aVertexPosition", 2, 0)
+		};
+	}
+}

OpenRA.Game/Graphics/ShaderBindings.cs

@@ -39,11 +39,14 @@ namespace OpenRA.Graphics
 		public abstract ShaderVertexAttribute[] Attributes { get; }
 
 		protected ShaderBindings(string name)
+			: this(name, name) { }
+
+		protected ShaderBindings(string vertexName, string fragmentName)
 		{
 			Stride = Attributes.Sum(a => a.Components * 4);
-			VertexShaderName = name;
+			VertexShaderName = vertexName;
 			VertexShaderCode = GetShaderCode(VertexShaderName + ".vert");
-			FragmentShaderName = name;
+			FragmentShaderName = fragmentName;
 			FragmentShaderCode = GetShaderCode(FragmentShaderName + ".frag");
 		}
 

OpenRA.Game/Graphics/WorldRenderer.cs

@@ -45,6 +45,8 @@ namespace OpenRA.Graphics
 
 		readonly List<IRenderable> renderablesBuffer = new();
 		readonly IRenderer[] renderers;
+		readonly IRenderPostProcessPass[] postProcessPasses;
+		readonly ITexture postProcessTexture;
 
 		internal WorldRenderer(ModData modData, World world)
 		{
@@ -71,6 +73,10 @@ namespace OpenRA.Graphics
 			terrainRenderer = world.WorldActor.TraitOrDefault<IRenderTerrain>();
 
 			debugVis = Exts.Lazy(() => world.WorldActor.TraitOrDefault<DebugVisualizations>());
+
+			postProcessPasses = world.WorldActor.TraitsImplementing<IRenderPostProcessPass>().ToArray();
+			if (postProcessPasses.Length > 0)
+				postProcessTexture = Game.Renderer.Context.CreateTexture();
 		}
 
 		public void BeginFrame()
@@ -284,6 +290,8 @@ namespace OpenRA.Graphics
 			if (enableDepthBuffer)
 				Game.Renderer.ClearDepthBuffer();
 
+			ApplyPostProcessing(PostProcessPassType.AfterActors);
+
 			World.ApplyToActorsWithTrait<IRenderAboveWorld>((actor, trait) =>
 			{
 				if (actor.IsInWorld && !actor.Disposed)
@@ -293,6 +301,8 @@ namespace OpenRA.Graphics
 			if (enableDepthBuffer)
 				Game.Renderer.ClearDepthBuffer();
 
+			ApplyPostProcessing(PostProcessPassType.AfterWorld);
+
 			World.ApplyToActorsWithTrait<IRenderShroud>((actor, trait) => trait.RenderShroud(this));
 
 			if (enableDepthBuffer)
@@ -306,9 +316,27 @@ namespace OpenRA.Graphics
 				foreach (var r in g)
 					r.Render(this);
 
+			ApplyPostProcessing(PostProcessPassType.AfterShroud);
+
 			Game.Renderer.Flush();
 		}
 
+		void ApplyPostProcessing(PostProcessPassType type)
+		{
+			var size = Game.Renderer.WorldFrameBufferSize;
+			var rect = new Rectangle(0, 0, size.Width, size.Height);
+			foreach (var pass in postProcessPasses)
+			{
+				if (pass.Type != type || !pass.Enabled)
+					continue;
+
+				// Make a copy of the world texture to avoid reading and writing on the same buffer
+				Game.Renderer.Flush();
+				postProcessTexture.SetDataFromReadBuffer(rect);
+				pass.Draw(this, postProcessTexture);
+			}
+		}
+
 		public void DrawAnnotations()
 		{
 			Game.Renderer.EnableAntialiasingFilter();