I have just uploaded a new release of my gpc polygon clipper to:
This new release (v2.20) fixes some reliability problems present
in earlier versions, and adds exclusive-or to the set operations
which are available.
Here is a brief summary of its features:
* Computes difference, intersection, exclusive-or and union.
* Handles polygon sets of arbitrary complexity: multiple
contours, self-intersections, holes, concavities.
* Vertex ordering is arbitrary (clockwise / anticlockwise mix).
* The clipper may generate contour descriptions or give tristrip
* Degenerate input regions and coincident veritces / edges are
As well as clipping, the software may be used to:
* Merge together touching polygons.
* Triangulate arbitrary concave / holed / self-intersecting
The clipper is written in C. Documentation is available online
via the above WWW link.