Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions That Modify Movie Properties / Working With Movie Spatial Characteristics

GetTrackMatrix

The GetTrackMatrix function allows your application to retrieve a track's transformation matrix.

pascal void GetTrackMatrix (Track theTrack, MatrixRecord *matrix);

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).

matrix

Contains a pointer to a matrix structure. The GetTrackMatrix function returns the track's matrix into the structure referred to by this parameter.

DESCRIPTION

The Movie Toolbox uses a track's matrix to map a track from its own coordinate system into a movie's display coordinate system.

ERROR CODES

invalidTrack

-2009

This track is corrupted or invalid

SEE ALSO

You can set a track's matrix with the SetTrackMatrix function, which is described in the previous section.

The Movie Toolbox provides a number of functions that allow you to manipulate track matrices. See "Matrix Functions" on page 2-321 for information about these functions.