order_bgra
typedef blender_rgba<rgba8, order_bgra> blender_bgra32; //----blender_bgra32
typedef blender_rgba_pre<rgba8, order_bgra> blender_bgra32_pre; //----blender_bgra32_pre
typedef blender_rgba_plain<rgba8, order_bgra> blender_bgra32_plain; //----blender_bgra32_plain
typedef blender_rgba<rgba16, order_bgra> blender_bgra64; //----blender_bgra64
typedef blender_rgba_pre<rgba16, order_bgra> blender_bgra64_pre; //----blender_bgra64_pre
typedef agg::order_bgra order_type;