The RGB_GETALPHA macro retrieves the alpha component of an RGBA D3DCOLOR value.
RGBA_GETALPHA(rgb) ((rgb) >> 24)
The macros returns the alpha component.
Windows NT: Use version 4.0 or later.
Windows: Use Windows 95 or later. Available as a redistributable for Windows 95.
Windows CE: Unsupported.
Header: Declared in d3dtypes.h.