Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions That Modify Movie Properties / Working With Movie Spatial Characteristics

GetTrackDisplayBoundsRgn

The GetTrackDisplayBoundsRgn function allows your application to determine the region a track occupies in a movie's graphics world.

pascal RgnHandle GetTrackDisplayBoundsRgn (Track theTrack);

theTrack

Specifies the track for this operation. Your application obtains this track identifier from such Movie Toolbox functions as NewMovieTrack and GetMovieTrack (described on page 2-136 and page 2-188, respectively).

DESCRIPTION

This region is in the display coordinate system. This region, when intersected with the movie's display clipping region, describes which pixels in the movie's graphics world display information from the specified track. This region is valid for the current movie time.

The GetTrackDisplayBoundsRgn function allocates the region and returns a handle to the region. Your application must dispose of this region when you are done with it. If the track does not have a spatial representation at the current movie time, the function returns an empty region. If the function could not satisfy your request, it sets the returned handle to nil.

ERROR CODES

invalidTrack

-2009

This track is corrupted or invalid

Memory Manager errors

SEE ALSO

If you want to determine the track's boundary region over a specified time segment, you can use the GetTrackSegmentDisplayBoundsRgn function, which is described in the next section.