The ICM_DRAW_BEGIN message is sent to a rendering driver to prepare it for drawing data.
Parameters
dwParam1
Specifies a pointer to an ICDRAWBEGIN data structure describing the input format.
dwParam2
Specifies the size of the ICDRAWBEGIN data structure describing the input format.
Return Value
Returns ICERR_OK if the driver supports drawing the data to the screen in the manner and format specified. Otherwise, returns ICERR_BADFORMAT if the input or output format is not supported, or ICERR_NOTSUPPORTED if the message is not supported.
Comments
If the driver is to decompress data into a buffer instead of drawing directly to the screen, ICM_DECOMPRESS_BEGIN is sent rather than this one.
If the driver does not support drawing directly to the screen, it should return ICERR_NOTSUPPORTED.
The ICM_DRAW_BEGIN and ICM_DRAW_END messages do not nest. If your driver receives ICM_DRAW_BEGIN before decompression is stopped with ICM_DRAW_END, it should restart decompression with new parameters.