Change Shader.Render to Shader.PrepareRender.

Instead of running the shader operation as an action, just run it after the shader is prepared.

OpenRA.Game/Graphics/PlatformInterfaces.cs

@@ -89,7 +89,7 @@ namespace OpenRA
 		void SetVec(string name, float[] vec, int length);
 		void SetTexture(string param, ITexture texture);
 		void SetMatrix(string param, float[] mtx);
-		void Render(Action a);
+		void PrepareRender();
 	}
 
 	public enum TextureScaleFilter { Nearest, Linear }