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You can define a procedure to access QuickTime VR's prescreen buffer.
pascal OSErr MyImagingCompleteProc (QTVRInstance qtvr, SInt32 refCon);
Your MyImagingCompleteProc function is called whenever QuickTime VR is finished drawing an image into the prescreen buffer associated with the movie specified by the qtvr parameter. When your function is called, the drawing environment is set up so that you can draw directly into the current graphics world. Once your function returns, QuickTime VR copies the prescreen buffer to the final destination.
If the value of the kQTVRImagingDirectDraw imaging property of the specified movie is true , then images are computed and drawn directly to the final destination without first being drawn into the prescreen buffer maintained by QuickTime VR. If your application has installed a prescreen buffer imaging completion procedure, QuickTime VR temporarilty overrides the setting of the kQTVRImagingDirectDraw property and calls your MyImagingCompleteProc function after drawing into the prescreen buffer.
Use QTVRSetPrescreenImagingCompleteProc (link) to install a prescreen buffer imaging completion procedure. See Listing 2-11 for a sample prescreen buffer imaging completion procedure.
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