Replace ChronoshiftPaletteEffect with a post-processing shader.

OpenRA.Mods.Cnc/Activities/Teleport.cs

@@ -101,7 +101,7 @@ namespace OpenRA.Mods.Cnc.Activities
 
 			// Trigger screen desaturate effect
 			if (screenFlash)
-				foreach (var a in self.World.ActorsWithTrait<ChronoshiftPaletteEffect>())
+				foreach (var a in self.World.ActorsWithTrait<ChronoshiftPostProcessEffect>())
 					a.Trait.Enable();
 
 			if (teleporter != null && self != teleporter && !teleporter.Disposed)

OpenRA.Mods.Cnc/Traits/ConyardChronoReturn.cs

@@ -213,7 +213,7 @@ namespace OpenRA.Mods.Cnc.Traits
 				TriggerVortex();
 
 			// Trigger screen desaturate effect
-			foreach (var cpa in self.World.ActorsWithTrait<ChronoshiftPaletteEffect>())
+			foreach (var cpa in self.World.ActorsWithTrait<ChronoshiftPostProcessEffect>())
 				cpa.Trait.Enable();
 
 			Game.Sound.Play(SoundType.World, info.ChronoshiftSound, self.CenterPosition);

OpenRA.Mods.Cnc/Traits/PaletteEffects/ChronoshiftPostProcessEffect.cs

@@ -9,29 +9,29 @@
  */
 #endregion
 
-using System.Collections.Generic;
 using OpenRA.Graphics;
-using OpenRA.Primitives;
+using OpenRA.Mods.Common.Traits;
 using OpenRA.Traits;
 
 namespace OpenRA.Mods.Cnc.Traits
 {
 	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
 	[Desc("Apply palette full screen rotations during chronoshifts. Add this to the world actor.")]
-	public class ChronoshiftPaletteEffectInfo : TraitInfo
+	public class ChronoshiftPostProcessEffectInfo : TraitInfo
 	{
 		[Desc("Measured in ticks.")]
 		public readonly int ChronoEffectLength = 60;
 
-		public override object Create(ActorInitializer init) { return new ChronoshiftPaletteEffect(this); }
+		public override object Create(ActorInitializer init) { return new ChronoshiftPostProcessEffect(this); }
 	}
 
-	public class ChronoshiftPaletteEffect : IPaletteModifier, ITick
+	public class ChronoshiftPostProcessEffect : RenderPostProcessPassBase, ITick
 	{
-		readonly ChronoshiftPaletteEffectInfo info;
+		readonly ChronoshiftPostProcessEffectInfo info;
 		int remainingFrames;
 
-		public ChronoshiftPaletteEffect(ChronoshiftPaletteEffectInfo info)
+		public ChronoshiftPostProcessEffect(ChronoshiftPostProcessEffectInfo info)
+			: base("chronoshift", PostProcessPassType.AfterWorld)
 		{
 			this.info = info;
 		}
@@ -47,23 +47,10 @@ namespace OpenRA.Mods.Cnc.Traits
 				remainingFrames--;
 		}
 
-		void IPaletteModifier.AdjustPalette(IReadOnlyDictionary<string, MutablePalette> palettes)
+		protected override bool Enabled => remainingFrames > 0;
+		protected override void PrepareRender(WorldRenderer wr, IShader shader)
 		{
-			if (remainingFrames == 0)
-				return;
-
-			var frac = (float)remainingFrames / info.ChronoEffectLength;
-
-			foreach (var pal in palettes)
-			{
-				for (var x = 0; x < Palette.Size; x++)
-				{
-					var orig = pal.Value.GetColor(x);
-					var lum = (int)(255 * orig.GetBrightness());
-					var desat = Color.FromArgb(orig.A, lum, lum, lum);
-					pal.Value.SetColor(x, Exts.ColorLerp(frac, orig, desat));
-				}
-			}
+			shader.SetVec("Blend", (float)remainingFrames / info.ChronoEffectLength);
 		}
 	}
 }

OpenRA.Mods.Common/UpdateRules/Rules/20230801/ReplacePaletteModifiers.cs

@@ -18,11 +18,13 @@ namespace OpenRA.Mods.Common.UpdateRules.Rules
 		public override string Name => "Replace palette modifiers with post-processing shaders.";
 
 		public override string Description =>
-			"MenuPaletteEffect is renamed to MenuPostProcessEffect.";
+			"MenuPaletteEffect is renamed to MenuPostProcessEffect.\n" +
+			"ChronoshiftPaletteEffect is renamed to ChronoshiftPostProcessEffect.";
 
 		public override IEnumerable<string> UpdateActorNode(ModData modData, MiniYamlNodeBuilder actorNode)
 		{
 			actorNode.RenameChildrenMatching("MenuPaletteEffect", "MenuPostProcessEffect");
+			actorNode.RenameChildrenMatching("ChronoshiftPaletteEffect", "ChronoshiftPostProcessEffect");
 
 			yield break;
 		}

glsl/postprocess_chronoshift.frag

@@ -0,0 +1,31 @@
+#version {VERSION}
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform float Blend;
+uniform sampler2D WorldTexture;
+
+#if __VERSION__ == 120
+uniform vec2 WorldTextureSize;
+#else
+out vec4 fragColor;
+#endif
+
+void main()
+{
+#if __VERSION__ == 120
+	vec4 c = texture2D(WorldTexture, gl_FragCoord.xy / WorldTextureSize);
+#else
+	vec4 c = texture(WorldTexture, gl_FragCoord.xy / textureSize(WorldTexture, 0));
+#endif
+
+	float lum = 0.5 * (min(c.r, min(c.g, c.b)) + max(c.r, max(c.g, c.b)));
+	c = vec4(lum, lum, lum, c.a) * Blend + c * (1.0 - Blend);
+
+	#if __VERSION__ == 120
+	gl_FragColor = c;
+	#else
+	fragColor = c;
+	#endif
+}

mods/ra/maps/mousetrap/rules.yaml

@@ -22,7 +22,7 @@ World:
 			ClearNoSmudges: 100
 		
 ^Palettes:
-	-ChronoshiftPaletteEffect:
+	-ChronoshiftPostProcessEffect:
 
 # Used in ChronoEffect.
 1TNK:

mods/ra/rules/palettes.yaml

@@ -99,7 +99,7 @@
 		RotationBase: 32
 	LightPaletteRotator:
 		ExcludePalettes: terrain, effect, desert
-	ChronoshiftPaletteEffect:
+	ChronoshiftPostProcessEffect:
 	FlashPaletteEffect@NUKE:
 		Type: Nuke
 	IndexedPalette@CIV2: