Fix a bug causing TextureAtlas to be premultiplied twice

Author: tlgkccampbell

TwistedLogik.Ultraviolet Tests/Resources/Expected/Graphics/TextureAtlas_LoadsAndRendersCorrectly_FromJson.png

@@ -204,9 +204,6 @@ public override Texture2D CreateTexture(Boolean premultiplyAlpha)
 
             using (var copysurf = new SDL_Surface(Width, Height))
             {
-                if (SDL.SetSurfaceBlendMode(nativesurf.Native, SDL_BlendMode.NONE) < 0)
-                    throw new SDL2Exception();
-
                 if (SDL.BlitSurface(nativesurf.Native, null, copysurf.Native, null) < 0)
                     throw new SDL2Exception();
 
@@ -330,9 +327,6 @@ private static void BlitInternal(OpenGLSurface2D src, Rectangle srcRect, OpenGLS
             var sdlSrcRect = new SDL_Rect() { x = srcRect.X, y = srcRect.Y, w = srcRect.Width, h = srcRect.Height };
             var sdlDstRect = new SDL_Rect() { x = dstRect.X, y = dstRect.Y, w = dstRect.Width, h = dstRect.Height };
 
-            if (SDL.SetSurfaceBlendMode(src.nativesurf.Native, SDL_BlendMode.NONE) < 0)
-                throw new SDL2Exception();
-
             if (srcRect.Width != dstRect.Width || srcRect.Height != dstRect.Height)
             {
                 if (SDL.BlitScaled(src.nativesurf.Native, &sdlSrcRect, dst.nativesurf.Native, &sdlDstRect) < 0)

TwistedLogik.Ultraviolet Tests/Resources/Expected/Graphics/TextureAtlas_LoadsAndRendersCorrectly_FromPreprocessedAsset.png

@@ -19,6 +19,9 @@ public SDL_Surface(Int32 width, Int32 height)
         {
             if ((this.ptr = SDL.CreateRGBSurface(0, width, height, 32, rmask, gmask, bmask, amask)) == null)
                 throw new SDL2Exception();
+
+            if (SDL.SetSurfaceBlendMode(this.ptr, SDL_BlendMode.NONE) < 0)
+                throw new SDL2Exception();
         }
 
         /// <summary>
@@ -34,6 +37,9 @@ public SDL_Surface(SDL_Surface_Native* src)
             if (dst == null)
                 throw new SDL2Exception();
 
+            if (SDL.SetSurfaceBlendMode(dst, SDL_BlendMode.NONE) < 0)
+                throw new SDL2Exception();
+
             if (SDL.BlitSurface(src, null, dst, null) < 0)
                 throw new SDL2Exception();