public static extern void gs_blend_function_separate(gs_blend_type src_c, gs_blend_type dest_c, gs_blend_type src_a, gs_blend_type dest_a);
public static extern void gs_blend_function_separate(gs_blend_type src_c, gs_blend_type dest_c, gs_blend_type src_a, gs_blend_type dest_a);
public static extern void gs_blend_function(gs_blend_type src, gs_blend_type dest);
public static extern void gs_blend_function(gs_blend_type src, gs_blend_type dest);