6.19  region%

A region% object specifies a portion of a drawing area (possibly discontinuous) for clipping drawing operations.

Each region% object is associated to a particular dc<%> object, specified when the region is created. A region can only be used with its associated dc<%> object, and changing the origin or scale of a drawing context invalidates its associated regions. (The region can still be used after the origin or scale is changed, but the results are platform- and device-dependent.)

See also set-clipping-region in dc<%> and get-clipping-region in dc<%>.