DescribePixelFormat
[New
- Windows 95, OEM Service Release 2]
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 |
|
); |
|
Parameters
hdc
Specifies the
device context.
iPixelFormat
Index that
specifies the pixel format. The pixel formats that a device context supports
are identified by positive one-based integer indexes.
nBytes
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).
ppfd
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 Values
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.
Remarks
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);
See Also