MyBackBufferImagingProc2

MyBackBufferImagingProc

You can define a procedure to access QuickTime VR's back buffer.

pascal OSErr MyBackBufferImagingProc (
                     QTVRInstance qtvr,
                     Rect *drawRect,
                     UInt16 areaIndex,
                     UInt32 flagsIn,
                     UInt32 *flagsOut,
                     SInt32 refCon);

qtvr

An instance of a QuickTime VR movie.

drawRect

The rectangle, in local coordinates of the graphics world, of the area of interest.

areaIndex

The index, in the array of area of interest structures whose address was passed to QTVRSetBackBufferImagingProc , of the area of interest.

flagsIn

On entry, a set of bit flags that specify the event or operation that caused your procedure to be called, as well as other information about the state of the back buffer when your procedure is called. See "Back Buffer Imaging Procedure Flags" for a description of the available flags.

flagsOut

On exit, a set of bit flags that indicate what actions you performed in your procedure. See "Back Buffer Imaging Procedure Flags" for a description of the available flags.

refCon

The reference constant specified in the call to QTVRSetBackBufferImagingProc that installed this procedure.

function result

A result code.

DESCRIPTION

Your MyBackBufferImagingProc function is called at the times specified by the flags parameter to the call to QTVRSetBackBufferImagingProc that installed that function as a back buffer imaging procedure. When your function is called, the drawing environment is set up so that you can draw directly into the current graphics world.

If the area of interest wraps around the end of the back buffer, the rectangle specified by the drawRect parameter is in the coordinates of an intermediate buffer that is copied into the actual back buffer when your procedure returns.

You can call the QTVRRefreshBackBuffer function (link) in your back buffer imaging procedure to refresh the current rectangle (that is, the rectangle specified by the drawRect parameter).

MyBackBufferImagingProc

DESCRIPTION

SEE ALSO