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, // device context of interest int iPixelFormat, // pixel format selector UINT nBytes, // size of buffer pointed to by ppfd LPPIXELFORMATDESCRIPTOR ppfd // pointer to structure to receive pixel // format data );
- 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.
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.
The following code sample shows DescribePixelFormat usage:
PIXELFORMATDESCRIPTOR pfd; HDC hdc; int iPixelFormat; iPixelFormat = 1; // obtain detailed information about // the device context's first pixel format DescribePixelFormat(hdc, iPixelFormat, sizeof(PIXELFORMATDESCRIPTOR), &pfd);
Windows NT/2000: Requires Windows NT 3.5 or later.
Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
Header: Declared in wingdi.h.
Import Library: Use gdi32.lib.