ICM_DRAW_BEGIN

See also ICDrawBegin, ICM_DECOMPRESS_BEGIN, ICM_DRAW, ICM_DRAW_END, ICM_DRAW_START

wParam = (DWORD) (LPVOID) &icdrwBgn;
lParam = sizeof(ICDRAW);

Notifies a rendering driver to prepare to draw data.

Returns ICERR_OK if the driver supports drawing the data to the screen in the specified manner and format, or an error code otherwise. The following values are defined:

ICERR_OK	Indicates no error occurred.
ICERR_BADFORMAT	Indicates the input or output format is not supported.
ICERR_NOTSUPPORTED	Indicates the driver does not draw directly to the screen or does not support this message.

wParam

Address of an ICDRAWBEGIN structure describing the input format.

lParam

Size, in bytes, of the ICDRAWBEGIN structure.

If you want the driver to decompress data into a buffer, send the ICM_DECOMPRESS_BEGIN message.

ICM_DRAW_BEGIN and ICM_DRAW_END 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.