freepascal.compiler/packages/extra/ptc/c_api/clipperd.inc

{ clip a single area against clip area }
Procedure ptc_clipper_clip(area, clip, clipped : TPTC_AREA);

{ clip source and destination areas against source and destination clip areas }
Procedure ptc_clipper_clip_complex(source, clip_source, clipped_source, destination, clip_destination, clipped_destination : TPTC_AREA);