The DrvDescribePixelFormat function describes the pixel format for a device-specified PDEV by writing a pixel format description to a PIXELFORMATDESCRIPTOR structure.
LONG DrvDescribePixelFormat( DHPDEV dhpdev, LONG iPixelFormat, ULONG cjpfd, PIXELFORMATDESCRIPTOR *ppfd );
Identifies the device for which pixel format information is requested.
Specifies the index number of the requested pixel format.
Specifies the maximum number of bytes that can be written to the structure pointed to by ppfd.
Pointer to a PIXELFORMATDESCRIPTOR structure (described in the Microsoft Windows SDK documentation) that is to receive information about the pixel format. This parameter can be NULL.
The return value is the maximum pixel format index if the function is successful. Otherwise, it is zero, and an error code is logged.
A display driver that supports 3D graphics hardware can support windows with different pixel formats on a single display surface. The pixel format must correspond to a configuration supported by the graphics hardware.
DrvDescribePixelFormat fills in the structure pointed to by ppfd if this parameter is not NULL.
The returned maximum pixel format index can be used by applications that need to obtain a device context's maximum pixel format index. The pixel formats that a device supports are identified by positive one-based integer indices.
The pixel format functions are used in conjunction with the window object services functions to track and update pixel formats of windows on a display surface.