Clipping Region Atoms

QuickTime Movie File Format Specification, May 1996

Clipping Region Atoms

The clipping region atom contains the data that specifies the clipping region, including its size and bounding box and region. Clipping region atoms have an atom type value of 'crgn' .

The layout of the clipping region atom is shown in Figure 0-11 .

Clipping region atoms contain the following data elements.

Size: A 32-bit integer that specifies the number of bytes in this clipping region atom.
Type: A 32-bit integer that identifies the atom type; this field must be set to 'crgn' .
Region size
Region boundary box
Clipping region data: The Region size, Region boundary box, and Clipping region data fields constitute a QuickDraw region. See Inside Macintosh: Imaging for details on QuickDraw regions.