The ICM_DRAW_WINDOW message is sent to a rendering driver when the window specified for ICM_DRAW_BEGIN has moved, or has become totally obscured. This message is used by overlay drivers so they can draw when the window is obscured or moved.
Parameters
dwParam1
Points to the destination rectangle in screen coordinates. If dwParam1 points to an empty rectangle, drawing should be turned off.
dwParam2
Not used.
Return Value
Returns ICERR_OK if successful.
Comments
This message is only supported by hardware that does its own asynchronous decompression, timing, and drawing.
The rectangle is empty if the window is totally hidden by other windows. Drivers should turn off overlay hardware when the rectangle is empty.