spine-xna no longer premultiplies alpha on load. Do it when packing the atlas.

This is just simpler all around. The renderer has a setting to know if premultiplied is being used. #121

spine-xna/example/data/spineboy.atlas

@@ -1,166 +1,131 @@
 
 spineboy.png
 format: RGBA8888
-filter: Linear,Linear
+filter: Nearest,Nearest
 repeat: none
-head
+eyes
   rotate: false
-  xy: 1, 122
+  xy: 447, 44
+  size: 34, 27
+  orig: 34, 27
+  offset: 0, 0
+  index: -1
+eyes-closed
+  rotate: true
+  xy: 483, 37
+  size: 34, 27
+  orig: 34, 27
+  offset: 0, 0
+  index: -1
+head
+  rotate: true
+  xy: 2, 5
   size: 121, 132
   orig: 121, 132
   offset: 0, 0
   index: -1
-torso
-  rotate: false
-  xy: 1, 28
-  size: 68, 92
-  orig: 68, 92
-  offset: 0, 0
-  index: -1
-left-pant-bottom
-  rotate: false
-  xy: 1, 4
-  size: 44, 22
-  orig: 44, 22
-  offset: 0, 0
-  index: -1
-right-pant-bottom
-  rotate: false
-  xy: 47, 8
-  size: 46, 18
-  orig: 46, 18
-  offset: 0, 0
-  index: -1
-right-upper-leg
-  rotate: false
-  xy: 71, 50
-  size: 44, 70
-  orig: 44, 70
-  offset: 0, 0
-  index: -1
-pelvis
-  rotate: false
-  xy: 95, 1
-  size: 63, 47
-  orig: 63, 47
-  offset: 0, 0
-  index: -1
-left-upper-leg
-  rotate: false
-  xy: 117, 53
-  size: 33, 67
-  orig: 33, 67
-  offset: 0, 0
-  index: -1
-right-foot
-  rotate: false
-  xy: 160, 224
-  size: 67, 30
-  orig: 67, 30
-  offset: 0, 0
-  index: -1
-left-shoulder
-  rotate: false
-  xy: 124, 201
-  size: 34, 53
-  orig: 34, 53
-  offset: 0, 0
-  index: -1
-left-ankle
-  rotate: false
-  xy: 229, 222
-  size: 25, 32
-  orig: 25, 32
-  offset: 0, 0
-  index: -1
-left-foot
-  rotate: false
-  xy: 160, 192
-  size: 65, 30
-  orig: 65, 30
-  offset: 0, 0
-  index: -1
-neck
-  rotate: false
-  xy: 124, 171
-  size: 34, 28
-  orig: 34, 28
-  offset: 0, 0
-  index: -1
-right-arm
-  rotate: false
-  xy: 124, 124
-  size: 21, 45
-  orig: 21, 45
-  offset: 0, 0
-  index: -1
-right-ankle
-  rotate: false
-  xy: 227, 190
-  size: 25, 30
-  orig: 25, 30
-  offset: 0, 0
-  index: -1
-left-hand
-  rotate: false
-  xy: 147, 131
-  size: 35, 38
-  orig: 35, 38
-  offset: 0, 0
-  index: -1
 left-arm
-  rotate: false
-  xy: 184, 161
+  rotate: true
+  xy: 382, 40
   size: 35, 29
   orig: 35, 29
   offset: 0, 0
   index: -1
-eyes-closed
+left-foot
   rotate: false
-  xy: 221, 161
-  size: 34, 27
-  orig: 34, 27
+  xy: 205, 2
+  size: 65, 30
+  orig: 65, 30
   offset: 0, 0
   index: -1
-right-lower-leg
+left-hand
   rotate: false
-  xy: 152, 65
-  size: 51, 64
-  orig: 51, 64
-  offset: 0, 0
-  index: -1
-right-foot-idle
-  rotate: false
-  xy: 184, 131
-  size: 53, 28
-  orig: 53, 28
+  xy: 272, 7
+  size: 35, 38
+  orig: 35, 38
   offset: 0, 0
   index: -1
 left-lower-leg
-  rotate: false
-  xy: 205, 65
+  rotate: true
+  xy: 331, 77
   size: 49, 64
   orig: 49, 64
   offset: 0, 0
   index: -1
-right-shoulder
+left-shoulder
   rotate: false
-  xy: 160, 12
-  size: 52, 51
-  orig: 52, 51
+  xy: 462, 73
+  size: 34, 53
+  orig: 34, 53
   offset: 0, 0
   index: -1
-eyes
+left-upper-leg
+  rotate: true
+  xy: 259, 47
+  size: 33, 67
+  orig: 33, 67
+  offset: 0, 0
+  index: -1
+neck
   rotate: false
-  xy: 214, 36
-  size: 34, 27
-  orig: 34, 27
+  xy: 382, 10
+  size: 34, 28
+  orig: 34, 28
+  offset: 0, 0
+  index: -1
+pelvis
+  rotate: false
+  xy: 397, 79
+  size: 63, 47
+  orig: 63, 47
+  offset: 0, 0
+  index: -1
+right-arm
+  rotate: true
+  xy: 206, 39
+  size: 21, 45
+  orig: 21, 45
+  offset: 0, 0
+  index: -1
+right-foot
+  rotate: false
+  xy: 136, 2
+  size: 67, 30
+  orig: 67, 30
   offset: 0, 0
   index: -1
 right-hand
   rotate: false
-  xy: 214, 2
+  xy: 413, 45
   size: 32, 32
   orig: 32, 32
   offset: 0, 0
   index: -1
+right-lower-leg
+  rotate: false
+  xy: 206, 62
+  size: 51, 64
+  orig: 51, 64
+  offset: 0, 0
+  index: -1
+right-shoulder
+  rotate: false
+  xy: 328, 24
+  size: 52, 51
+  orig: 52, 51
+  offset: 0, 0
+  index: -1
+right-upper-leg
+  rotate: true
+  xy: 259, 82
+  size: 44, 70
+  orig: 44, 70
+  offset: 0, 0
+  index: -1
+torso
+  rotate: false
+  xy: 136, 34
+  size: 68, 92
+  orig: 68, 92
+  offset: 0, 0
+  index: -1

spine-xna/example/src/ExampleGame.cs

@@ -69,6 +69,7 @@ namespace Spine {
 
 		protected override void LoadContent () {
 			skeletonRenderer = new SkeletonRenderer(GraphicsDevice);
+			skeletonRenderer.PremultipliedAlpha = true;
 
 			String name = "spineboy"; // "goblins";
 

spine-xna/src/SkeletonRenderer.cs

@@ -43,6 +43,10 @@ namespace Spine {
 		BasicEffect effect;
 		RasterizerState rasterizerState;
 		float[] vertices = new float[8];
+		BlendState defaultBlendState;
+
+		private bool premultipliedAlpha;
+		public bool PremultipliedAlpha { get { return premultipliedAlpha; } set { premultipliedAlpha = value; } }
 
 		public SkeletonRenderer (GraphicsDevice device) {
 			this.device = device;
@@ -62,8 +66,10 @@ namespace Spine {
 		}
 
 		public void Begin () {
+			defaultBlendState = premultipliedAlpha ? BlendState.AlphaBlend : BlendState.NonPremultiplied;
+
 			device.RasterizerState = rasterizerState;
-			device.BlendState = BlendState.AlphaBlend; // spine-xna textures are premultiplied on load, see Util.cs.
+			device.BlendState = defaultBlendState;
 
 			effect.Projection = Matrix.CreateOrthographicOffCenter(0, device.Viewport.Width, device.Viewport.Height, 0, 1, 0);
 		}
@@ -83,7 +89,7 @@ namespace Spine {
 				Slot slot = drawOrder[i];
 				RegionAttachment regionAttachment = slot.Attachment as RegionAttachment;
 				if (regionAttachment != null) {
-					BlendState blend = slot.Data.AdditiveBlending ? BlendState.Additive : BlendState.AlphaBlend;
+					BlendState blend = slot.Data.AdditiveBlending ? BlendState.Additive : defaultBlendState;
 					if (device.BlendState != blend) {
 						End();
 						device.BlendState = blend;
@@ -93,8 +99,12 @@ namespace Spine {
 					AtlasRegion region = (AtlasRegion)regionAttachment.RendererObject;
 					item.Texture = (Texture2D)region.page.rendererObject;
 
+					Color color;
 					float a = skeletonA * slot.A;
-					Color color = new Color(skeletonR * slot.R * a, skeletonG * slot.G * a, skeletonB * slot.B * a, a);
+					if (premultipliedAlpha)
+						color = new Color(skeletonR * slot.R * a, skeletonG * slot.G * a, skeletonB * slot.B * a, a);
+					else
+						color = new Color(skeletonR * slot.R, skeletonG * slot.G, skeletonB * slot.B, a);
 					item.vertexTL.Color = color;
 					item.vertexBL.Color = color;
 					item.vertexBR.Color = color;

spine-xna/src/Util.cs

@@ -71,56 +71,7 @@ namespace Spine {
 #endif
 
 		static public Texture2D LoadTexture (GraphicsDevice device, Stream input) {
-			Texture2D file = Texture2D.FromStream(device, input);
-
-			// Setup a render target to hold our final texture which will have premulitplied alpha values
-			RenderTarget2D result = new RenderTarget2D(device, file.Width, file.Height);
-			device.SetRenderTarget(result);
-			device.Clear(Color.Black);
-
-			// Multiply each color by the source alpha, and write in just the color values into the final texture
-			BlendState blendColor = new BlendState();
-			blendColor.ColorWriteChannels = ColorWriteChannels.Red | ColorWriteChannels.Green | ColorWriteChannels.Blue;
-			blendColor.AlphaDestinationBlend = Blend.Zero;
-			blendColor.ColorDestinationBlend = Blend.Zero;
-			blendColor.AlphaSourceBlend = Blend.SourceAlpha;
-			blendColor.ColorSourceBlend = Blend.SourceAlpha;
-
-			SpriteBatch spriteBatch = new SpriteBatch(device);
-			spriteBatch.Begin(SpriteSortMode.Immediate, blendColor);
-			spriteBatch.Draw(file, file.Bounds, Color.White);
-			spriteBatch.End();
-
-			// Now copy over the alpha values from the PNG source texture to the final one, without multiplying them
-			BlendState blendAlpha = new BlendState();
-			blendAlpha.ColorWriteChannels = ColorWriteChannels.Alpha;
-			blendAlpha.AlphaDestinationBlend = Blend.Zero;
-			blendAlpha.ColorDestinationBlend = Blend.Zero;
-			blendAlpha.AlphaSourceBlend = Blend.One;
-			blendAlpha.ColorSourceBlend = Blend.One;
-
-			spriteBatch.Begin(SpriteSortMode.Immediate, blendAlpha);
-			spriteBatch.Draw(file, file.Bounds, Color.White);
-			spriteBatch.End();
-
-			// Release the GPU back to drawing to the screen.
-			device.SetRenderTarget(null);
-			spriteBatch.Dispose();
-			file.Dispose();
-
-#if IOS
-			return result as Texture2D;
-#else
-			// RenderTarget2D are volatile and will be lost on screen resolution changes.
-			// So instead of using this directly, we create a non-voliate Texture2D.
-			// This is computationally slower, but should be safe as long as it is done on load.
-			Texture2D resultTexture = new Texture2D(device, file.Width, file.Height);
-			Color[] resultContent = new Color[Convert.ToInt32(file.Width * file.Height)];
-			result.GetData(resultContent);
-			resultTexture.SetData(resultContent);
-			result.Dispose(); // Dispose of the RenderTarget2D immediately.
-			return resultTexture;
-#endif
+			return Texture2D.FromStream(device, input);
 		}
 	}
 }