DescribePixelFormat function

The DescribePixelFormat function obtains information about the pixel format identified by iPixelFormat of the device associated with hdc. The function sets the members of the PIXELFORMATDESCRIPTOR structure pointed to by ppfd with that pixel format data.


int DescribePixelFormat(
  HDC                     hdc,
  int                     iPixelFormat,
  UINT                    nBytes,



Specifies the device context.


Index that specifies the pixel format. The pixel formats that a device context supports are identified by positive one-based integer indexes.


The size, in bytes, of the structure pointed to by ppfd. The DescribePixelFormat function stores no more than nBytes bytes of data to that structure. Set this value to sizeof(PIXELFORMATDESCRIPTOR).


Pointer to a PIXELFORMATDESCRIPTOR structure whose members the function sets with pixel format data. The function stores the number of bytes copied to the structure in the structure's nSize member. If, upon entry, ppfd is NULL, the function writes no data to the structure. This is useful when you only want to obtain the maximum pixel format index of a device context.

Return Value

If the function succeeds, the return value is the maximum pixel format index of the device context. In addition, the function sets the members of the PIXELFORMATDESCRIPTOR structure pointed to by ppfd according to the specified pixel format.

If the function fails, the return value is zero. To get extended error information, call GetLastError.


Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header wingdi.h
Library Gdi32.lib
DLL Gdi32.dll

See Also



OpenGL on Windows


Windows Functions