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You can use the QTVRSetBackBufferImagingProc function to install or remove a back buffer imaging procedure.
OSErr QTVRSetBackBufferImagingProc (
QTVRInstance qtvr,
BackBufferImagingUPP backBufferImagingProc,
UInt16 numAreas,
AreaOfInterest *areasOfInterest,
SInt32 refCon);
The QTVRSetBackBufferImagingProc function installs the procedure specified by the backBufferImagingProc parameter as a back buffer imaging procedure for the panoramic node specified by the qtvr parameter. You can use that procedure to draw directly into the back buffer.
The areasOfInterest parameter is a pointer to an array of area of interest structures that define the rectangular areas about which you want your back buffer imaging procedure to be notified. Your procedure is called for each area of interest as it becomes visible or not visible. You indicate when you want your procedure to be called for a particular area of interest by setting flags in the flags field in the corresponding area of interest structure.
The QuickTime VR Manager version 2.1 supports only one area of interest in this array. Future versions will support multiple areas of interest.
Note that coordinates in the back buffer are dependent on the current correction mode; as a result, you need to indicate the area you're interested in drawing into by specifying a pan angle and tilt angle to determine the upper-left corner of the area and a height and width relative to that corner. (Specifying a height and width instead of a second pair of pan and tilt angles for the bottom-right coordinate allows the rectangle to wrap around the edge of the panorama.)
To remove a previously installed back buffer imaging procedure, set backBufferImagingProc to nil .
Use QTVRSetPrescreenImagingCompleteProc (link) to install or remove a prescreen buffer imaging completion procedure.
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