Change the internal constant color from a (per-draw) vertex attribute to a uniform. Pack most built-in uniforms into a single vec4 array and update them all with a single glUniform call.

--HG--
branch : minor

src/modules/graphics/Shader.h

@@ -68,12 +68,8 @@ public:
 		BUILTIN_TEXTURE_VIDEO_Y,
 		BUILTIN_TEXTURE_VIDEO_CB,
 		BUILTIN_TEXTURE_VIDEO_CR,
-		BUILTIN_MATRIX_VIEW_FROM_LOCAL,
-		BUILTIN_MATRIX_CLIP_FROM_VIEW,
-		BUILTIN_MATRIX_CLIP_FROM_LOCAL,
-		BUILTIN_MATRIX_VIEW_NORMAL_FROM_LOCAL,
+		BUILTIN_UNIFORMS_PER_DRAW,
 		BUILTIN_POINT_SIZE,
-		BUILTIN_SCREEN_SIZE,
 		BUILTIN_MAX_ENUM
 	};
 
@@ -133,6 +129,16 @@ public:
 		Texture **textures;
 	};
 
+	// The members in here must respect uniform buffer alignment/padding rules.
+ 	struct BuiltinUniformData
+ 	{
+ 		Matrix4 transformMatrix;
+ 		Matrix4 projectionMatrix;
+ 		Vector4 normalMatrix[3]; // 3x3 matrix padded to an array of 3 vector4s.
+ 		Vector4 screenSizeParams;
+ 		Colorf constantColor;
+ 	};
+
 	// Pointer to currently active Shader.
 	static Shader *current;