Add Multiply blend mode for D2K move-flash and shroud.

OpenRA.FileFormats/Graphics/IGraphicsDevice.cs

@@ -31,7 +31,7 @@ namespace OpenRA.FileFormats.Graphics
 		IGraphicsDevice Create( Size size, WindowMode windowMode );
 	}
 
-	public enum BlendMode { None, Alpha, Additive, Subtractive }
+	public enum BlendMode { None, Alpha, Additive, Subtractive, Multiply }
 
 	public interface IGraphicsDevice
 	{

OpenRA.Mods.D2k/PaletteFromR8.cs

@@ -10,8 +10,8 @@
 
 using System.IO;
 using OpenRA.FileFormats;
-using OpenRA.Traits;
 using OpenRA.Graphics;
+using OpenRA.Traits;
 
 namespace OpenRA.Mods.RA
 {
@@ -24,6 +24,7 @@ namespace OpenRA.Mods.RA
 		[Desc("Palette byte offset")]
 		public readonly long Offset = 0;
 		public readonly bool AllowModifiers = true;
+		public readonly bool InvertColor = false;
 		
 		public object Create(ActorInitializer init) { return new PaletteFromR8(this); }
 	}
@@ -42,10 +43,11 @@ namespace OpenRA.Mods.RA
 
 				for (var i = 0; i < 256; i++)
 				{
-					// The custom palette is scaled into the range 0-128.
-					// This makes the move-flash match the original game, but may not be correct in other cases.
 					var packed = s.ReadUInt16();
-					colors[i] = (uint)((255 << 24) | ((packed & 0xF800) << 7) | ((packed & 0x7E0) << 4) | ((packed & 0x1f) << 2));
+					colors[i] = (uint)((255 << 24) | ((packed & 0xF800) << 8) | ((packed & 0x7E0) << 5) | ((packed & 0x1f) << 3));
+
+					if (info.InvertColor)
+						colors[i] ^= 0x00FFFFFF;
 				}
 			}
 

OpenRA.Renderer.Sdl2/Sdl2GraphicsDevice.cs

@@ -177,6 +177,12 @@ namespace OpenRA.Renderer.Sdl2
 					ErrorHandler.CheckGlError();
 					Gl.glBlendEquation(Gl.GL_FUNC_REVERSE_SUBTRACT);
 					break;
+				case BlendMode.Multiply:
+					Gl.glEnable(Gl.GL_BLEND);
+					ErrorHandler.CheckGlError();
+					Gl.glBlendFuncSeparate(Gl.GL_DST_COLOR, Gl.GL_ZERO, Gl.GL_ONE, Gl.GL_ONE_MINUS_SRC_ALPHA);
+					ErrorHandler.CheckGlError();
+					break;
 			}
 
 			ErrorHandler.CheckGlError();

OpenRA.Renderer.SdlCommon/SdlGraphics.cs

@@ -179,6 +179,12 @@ namespace OpenRA.Renderer.SdlCommon
 					ErrorHandler.CheckGlError();
 					Gl.glBlendEquation(Gl.GL_FUNC_REVERSE_SUBTRACT);
 					break;
+				case BlendMode.Multiply:
+					Gl.glEnable(Gl.GL_BLEND);
+					ErrorHandler.CheckGlError();
+					Gl.glBlendFuncSeparate(Gl.GL_DST_COLOR, Gl.GL_ZERO, Gl.GL_ONE, Gl.GL_ONE_MINUS_SRC_ALPHA);
+					ErrorHandler.CheckGlError();
+					break;
 			}
 			ErrorHandler.CheckGlError();
 		}

mods/d2k/rules/system.yaml

@@ -414,7 +414,7 @@ World:
 		Name: moveflash
 		Filename: DATA.R8
 		Offset: 2572352
-		A: 64
+		InvertColor: true
 	PaletteFromRGBA@disabled:
 		Name: disabled
 		R: 0

mods/d2k/sequences/misc.yaml

@@ -304,7 +304,7 @@ moveflsh:
 		Start: 3621
 		Length: 5
 		Tick: 80
-		BlendMode: Subtractive
+		BlendMode: Multiply
 
 resources:
 	spice: BLOXBASE