Pixel Format Functions
The following Win32 functions manage pixel formats.
| Win32 Function | Description |
|---|---|
| ChoosePixelFormat | Obtains the device context's pixel format that is the closest match to a specified pixel format. |
| SetPixelFormat | Sets a device context's current pixel format to the pixel format specified by a pixel format index. |
| GetPixelFormat | Obtains the pixel format index of a device context's current pixel format. |
| DescribePixelFormat | Given a device context and a pixel format index, fills in a PIXELFORMATDESCRIPTOR data structure with the pixel format's properties. |
| GetEnhMetaFilePixelFormat | Retrieves pixel format information for an enhanced metafile. |
The ChoosePixelFormat function returns a one-based pixel format index that identifies the best match from the device context's supported pixel formats.
The SetPixelFormat function identifies the desired format using a one-based pixel format index. Typically, you call ChoosePixelFormat to find a best-match pixel format, and then call SetPixelFormat with the result of ChoosePixelFormat.
If you call SetPixelFormat for a device context that references a window, SetPixelFormat also changes the pixel format of the window. Setting the pixel format of a window more than once can lead to significant complications for the Window Manager and for multithread applications, so it is not allowed. You can set the pixel format of a window only one time; after that, the window's pixel format cannot be changed.
The GetPixelFormat function returns a one-based pixel format index.
The DescribePixelFormat function takes the following as parameters:
- A handle to a device context
- A pixel format index
- A pointer to a PIXELFORMATDESCRIPTOR data structure
The DescribePixelFormat function returns with the members of PIXELFORMATDESCRIPTOR appropriately set.
The GetEnhMetaFilePixelFormat function returns the size of a metafile's pixel format and retrieves the pixel format information of the metafile.