Use premultiplied alpha for all textures and blending.

OpenRA.Game/Graphics/Sheet.cs

@@ -49,15 +49,9 @@ namespace OpenRA.Graphics
 			using (var bitmap = (Bitmap)Image.FromStream(stream))
 			{
 				Size = bitmap.Size;
+				data = new byte[4 * Size.Width * Size.Height];
 
-				var dataStride = 4 * Size.Width;
+				Util.FastCopyIntoSprite(new Sprite(this, bitmap.Bounds(), TextureChannel.Red), bitmap);
-				data = new byte[dataStride * Size.Height];
-
-				var bd = bitmap.LockBits(bitmap.Bounds(),
-					ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
-				for (var y = 0; y < Size.Height; y++)
-					Marshal.Copy(IntPtr.Add(bd.Scan0, y * bd.Stride), data, y * dataStride, dataStride);
-				bitmap.UnlockBits(bd);
 			}
 
 			ReleaseBuffer();

OpenRA.Game/Graphics/SpriteFont.cs

@@ -114,6 +114,7 @@ namespace OpenRA.Graphics
 
 			// A new bitmap is generated each time this property is accessed, so we do need to dispose it.
 			using (var bitmap = face.Glyph.Bitmap)
+			{
 				unsafe
 				{
 					var p = (byte*)bitmap.Buffer;
@@ -123,18 +124,23 @@ namespace OpenRA.Graphics
 					for (var j = 0; j < s.Size.Y; j++)
 					{
 						for (var i = 0; i < s.Size.X; i++)
+						{
 							if (p[i] != 0)
 							{
 								var q = destStride * (j + s.Bounds.Top) + 4 * (i + s.Bounds.Left);
-								dest[q] = c.Second.B;
+								var pmc = Util.PremultiplyAlpha(Color.FromArgb(p[i], c.Second));
-								dest[q + 1] = c.Second.G;
+
-								dest[q + 2] = c.Second.R;
+								dest[q] = pmc.B;
-								dest[q + 3] = p[i];
+								dest[q + 1] = pmc.G;
+								dest[q + 2] = pmc.R;
+								dest[q + 3] = pmc.A;
 							}
+						}
 
 						p += bitmap.Pitch;
 					}
 				}
+			}
 
 			s.Sheet.CommitBufferedData();
 

OpenRA.Game/Graphics/Util.cs

@@ -73,18 +73,37 @@ namespace OpenRA.Graphics
 
 			try
 			{
-				var data = dest.Sheet.GetData();
+				var destData = dest.Sheet.GetData();
-				var dataStride = dest.Sheet.Size.Width * 4;
+				var destStride = dest.Sheet.Size.Width;
-				var x = dest.Bounds.Left * 4;
+				var width = dest.Bounds.Width;
-				var width = dest.Bounds.Width * 4;
-				var y = dest.Bounds.Top;
 				var height = dest.Bounds.Height;
 
-				var bd = src.LockBits(src.Bounds(),
+				var srcData = src.LockBits(src.Bounds(),
-					ImageLockMode.ReadWrite, src.PixelFormat);
+					ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
-				for (var row = 0; row < height; row++)
+
-					Marshal.Copy(IntPtr.Add(bd.Scan0, row * bd.Stride), data, (y + row) * dataStride + x, width);
+				unsafe
-				src.UnlockBits(bd);
+				{
+					var c = (int*)srcData.Scan0;
+
+					// Cast the data to an int array so we can copy the src data directly
+					fixed (byte* bd = &destData[0])
+					{
+						var data = (int*)bd;
+						var x = dest.Bounds.Left;
+						var y = dest.Bounds.Top;
+
+						for (var j = 0; j < height; j++)
+						{
+							for (var i = 0; i < width; i++)
+							{
+								var cc = Color.FromArgb(*(c + (j * srcData.Stride >> 2) + i));
+								data[(y + j) * destStride + x + i] = PremultiplyAlpha(cc).ToArgb();
+							}
+						}
+					}
+				}
+
+				src.UnlockBits(srcData);
 			}
 			finally
 			{
@@ -93,6 +112,12 @@ namespace OpenRA.Graphics
 			}
 		}
 
+		public static Color PremultiplyAlpha(Color c)
+		{
+			var a = c.A / 255f;
+			return Color.FromArgb(c.A, (byte)(c.R * a + 0.5f), (byte)(c.G * a + 0.5f), (byte)(c.B * a + 0.5f));
+		}
+
 		public static float[] IdentityMatrix()
 		{
 			return Exts.MakeArray(16, j => (j % 5 == 0) ? 1.0f : 0);

OpenRA.Mods.Common/OpenRA.Mods.Common.csproj

@@ -643,6 +643,7 @@
     <Compile Include="Traits\World\EditorActorPreview.cs" />
     <Compile Include="Traits\World\EditorResourceLayer.cs" />
     <Compile Include="Widgets\EditorViewportControllerWidget.cs" />
+    <Compile Include="Traits\World\PaletteFromPaletteWithAlpha.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <PropertyGroup>

OpenRA.Mods.Common/Traits/World/PaletteFromPaletteWithAlpha.cs

@@ -0,0 +1,76 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2015 The OpenRA Developers (see AUTHORS)
+ * 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. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System.Collections.Generic;
+using System.Drawing;
+using OpenRA.Graphics;
+using OpenRA.Mods.Common.Traits;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.D2k.Traits
+{
+	[Desc("Create a palette by applying alpha transparency to another palette.")]
+	class PaletteFromPaletteWithAlphaInfo : ITraitInfo
+	{
+		[Desc("Internal palette name")]
+		public readonly string Name = null;
+
+		[Desc("The name of the palette to base off.")]
+		public readonly string BasePalette = null;
+
+		[Desc("Allow palette modifiers to change the palette.")]
+		public readonly bool AllowModifiers = true;
+
+		[Desc("Alpha component that is applied to the base palette.")]
+		public readonly float Alpha = 1.0f;
+
+		[Desc("Premultiply color by the alpha component.")]
+		public readonly bool Premultiply = true;
+
+		public object Create(ActorInitializer init) { return new PaletteFromPaletteWithAlpha(this); }
+	}
+
+	class PaletteFromPaletteWithAlpha : ILoadsPalettes, IProvidesAssetBrowserPalettes
+	{
+		readonly PaletteFromPaletteWithAlphaInfo info;
+
+		public PaletteFromPaletteWithAlpha(PaletteFromPaletteWithAlphaInfo info) { this.info = info; }
+
+		public void LoadPalettes(WorldRenderer wr)
+		{
+			var remap = new AlphaPaletteRemap(info.Alpha, info.Premultiply);
+			wr.AddPalette(info.Name, new ImmutablePalette(wr.Palette(info.BasePalette).Palette, remap), info.AllowModifiers);
+		}
+
+		public IEnumerable<string> PaletteNames { get { yield return info.Name; } }
+	}
+
+	class AlphaPaletteRemap : IPaletteRemap
+	{
+		readonly float alpha;
+		readonly bool premultiply;
+
+		public AlphaPaletteRemap(float alpha, bool premultiply)
+		{
+			this.alpha = alpha;
+			this.premultiply = premultiply;
+		}
+
+		public Color GetRemappedColor(Color original, int index)
+		{
+			var a = (int)(original.A * alpha).Clamp(0, 255);
+			var r = premultiply ? (int)(alpha * original.R + 0.5f).Clamp(0, 255) : original.R;
+			var g = premultiply ? (int)(alpha * original.G + 0.5f).Clamp(0, 255) : original.G;
+			var b = premultiply ? (int)(alpha * original.B + 0.5f).Clamp(0, 255) : original.B;
+
+			return Color.FromArgb(a, r, g, b);
+		}
+	}
+}

OpenRA.Mods.Common/Traits/World/PaletteFromRGBA.cs

@@ -8,6 +8,7 @@
  */
 #endregion
 
+using System.Drawing;
 using System.Linq;
 using OpenRA.Graphics;
 using OpenRA.Traits;
@@ -50,7 +51,11 @@ namespace OpenRA.Mods.Common.Traits
 			if (info.Tileset != null && info.Tileset.ToLowerInvariant() != world.Map.Tileset.ToLowerInvariant())
 				return;
 
-			var c = (uint)((info.A << 24) | (info.R << 16) | (info.G << 8) | info.B);
+			var a = info.A / 255f;
+			var r = (int)(a * info.R + 0.5f).Clamp(0, 255);
+			var g = (int)(a * info.G + 0.5f).Clamp(0, 255);
+			var b = (int)(a * info.B + 0.5f).Clamp(0, 255);
+			var c = (uint)Color.FromArgb(info.A, r, g, b).ToArgb();
 			wr.AddPalette(info.Name, new ImmutablePalette(Enumerable.Range(0, Palette.Size).Select(i => (i == 0) ? 0 : c)), info.AllowModifiers);
 		}
 	}

OpenRA.Mods.Common/Traits/World/ShroudPalette.cs

@@ -42,8 +42,8 @@ namespace OpenRA.Mods.Common.Traits
 
 		static readonly Color[] Fog = new[]
 		{
-			Color.Transparent, Color.Green,
+			Color.FromArgb(0, 0, 0, 0),
-			Color.Blue, Color.Yellow,
+			Color.Green, Color.Blue, Color.Yellow,
 			Color.FromArgb(128, 0, 0, 0),
 			Color.FromArgb(96, 0, 0, 0),
 			Color.FromArgb(64, 0, 0, 0),
@@ -52,8 +52,8 @@ namespace OpenRA.Mods.Common.Traits
 
 		static readonly Color[] Shroud = new[]
 		{
-			Color.Transparent, Color.Green,
+			Color.FromArgb(0, 0, 0, 0),
-			Color.Blue, Color.Yellow,
+			Color.Green, Color.Blue, Color.Yellow,
 			Color.Black,
 			Color.FromArgb(160, 0, 0, 0),
 			Color.FromArgb(128, 0, 0, 0),

OpenRA.Renderer.Sdl2/Sdl2GraphicsDevice.cs

@@ -259,7 +259,7 @@ namespace OpenRA.Renderer.Sdl2
 				case BlendMode.Alpha:
 					GL.Enable(EnableCap.Blend);
 					ErrorHandler.CheckGlError();
-					GL.BlendFunc(BlendingFactorSrc.SrcAlpha, BlendingFactorDest.OneMinusSrcAlpha);
+					GL.BlendFunc(BlendingFactorSrc.One, BlendingFactorDest.OneMinusSrcAlpha);
 					break;
 				case BlendMode.Additive:
 					GL.Enable(EnableCap.Blend);

mods/d2k/rules/palettes.yaml

@@ -49,6 +49,14 @@
 		G: 0
 		B: 0
 		A: 180
+	PaletteFromPaletteWithAlpha@effect75alpha:
+		Name: effect75alpha
+		BasePalette: effect
+		Alpha: 0.75
+	PaletteFromPaletteWithAlpha@effect50alpha:
+		Name: effect50alpha
+		BasePalette: effect
+		Alpha: 0.5
 	PaletteFromScaledPalette@starportlights:
 		Name: starportlights
 		BasePalette: d2k

mods/d2k/rules/vehicles.yaml

@@ -81,6 +81,7 @@ harvester:
 	LeavesHusk:
 		HuskActor: Harvester.Husk
 	WithHarvestAnimation:
+		Palette: effect50alpha
 	AttractsWorms:
 		Intensity: 700
 

mods/d2k/sequences/misc.yaml

@@ -71,30 +71,24 @@ small_trail:
 		Start: 3735
 		Length: 4
 		Tick: 80
-		BlendMode: SoftAdditive
 
 small_trail2:
 	idle: DATA.R8
 		Start: 3540
 		Length: 4
 		Tick: 80
-		BlendMode: SoftAdditive
 
 bazooka_trail:
 	idle: DATA.R8
 		Start: 3381
 		Length: 4
 		Tick: 80
-		BlendMode: Translucency
-		Alpha: 0.75
 
 bazooka_trail2:
 	idle: DATA.R8
 		Start: 3544
 		Length: 4
 		Tick: 80
-		BlendMode: Translucency
-		Alpha: 0.75
 
 deviator_trail:
 	idle: DATA.R8

mods/d2k/sequences/vehicles.yaml

@@ -23,7 +23,6 @@ harvester:
 		Tick: 80
 		ZOffset: 1
 		BlendMode: Multiply
-		Alpha: 0.5
 	dock: DATA.R8
 		Start: 3370
 		Length: 10

mods/d2k/weapons.yaml

@@ -34,6 +34,7 @@ Bazooka:
 		Image: RPG
 		RateOfTurn: 5
 		Trail: bazooka_trail
+		TrailPalette: effect75alpha
 		TrailInterval: 1
 		RangeLimit: 35
 	Warhead@1Dam: SpreadDamage
@@ -193,6 +194,7 @@ QuadRockets:
 		Image: RPG
 		RateOfTurn: 10
 		Trail: bazooka_trail2
+		TrailPalette: effect75alpha
 		TrailInterval: 1
 		Speed: 256
 		RangeLimit: 40

mods/ts/rules/palettes.yaml

@@ -73,6 +73,10 @@
 		G: 0
 		B: 0
 		A: 180
+	PaletteFromPaletteWithAlpha@placebuilding:
+		Name: placebuilding
+		BasePalette: ra
+		Alpha: 0.75
 	TSShroudPalette@shroud:
 		Type: Shroud
 	VoxelNormalsPalette@normals:

mods/ts/rules/player.yaml

@@ -30,7 +30,7 @@ Player:
 		LowPowerSlowdown: 3
 		SpeedUp: True
 	PlaceBuilding:
-		Palette: ra
+		Palette: placebuilding
 	SupportPowerManager:
 	ScriptTriggers:
 	MissionObjectives:

mods/ts/sequences/misc.yaml

@@ -1,8 +1,6 @@
 overlay:
 	Defaults: place
 		Offset: 0, -12
-		BlendMode: Translucency
-		Alpha: 0.75
 	build-valid-snow:
 	build-valid-temperat:
 	build-invalid:
@@ -114,10 +112,10 @@ explosion:
 		Length: *
 	building: twlt070
 	ionring: ring1
-		BlendMode: SoftAdditive
+		BlendMode: Additive
 		Tick: 120
 	pulse_explosion: pulsefx2
-		BlendMode: SoftAdditive
+		BlendMode: Additive
 		Tick: 80
 	small_watersplash: h2o_exp2
 	large_watersplash: h2o_exp1