Processing WM_PAINT Messages

Your window function must notify the Movie Player when it receives WM_PAINT messages for the stage window. To prompt the Movie Player to update the frame, use the mmpUpdate function, which has the following syntax:

BOOL mmpUpdate(idMovie, hDC, lpRect)

The parameters are a movie ID, the device context from BeginPaint, and a pointer to the invalid rectangle. See “Creating a Full-Screen Stage Window,” later in this chapter, for an example of how to handle a WM_PAINT message for a stage-window message handler.