Clipper

A Java port of Clipper - a polygon clipping library.

Based on the C# version clipper 5.1.6 by Angus Johnson

Porting Notes

• Int128 was implemented using BigIntegers for now as Java doesn't support unsigned longs.
• A polygon class was added instead of the using statement. List<Polygon> is used instead of Polygons.
• Exceptions are thrown as a RuntimeException, ClipperException.
• The more complex pass by reference calls were implemented using AtomicReferences.
• The naming of public methods and parameters was changed to match the common Java style.

Usage

Build with ant:

ant jar

Sample Code

import clipper.*;

...

List<Polygon> subj = new ArrayList<Polygon>();
subj.add(new Polygon());
subj.get(0).add(180, 200);
subj.get(0).add(260, 200);
subj.get(0).add(260, 150);
subj.get(0).add(180, 150);

subj.add(new Polygon());
subj.get(1).add(215, 160);
subj.get(1).add(230, 190);
subj.get(1).add(200, 190);

List<Polygon> clip = new ArrayList<Polygon>();
clip.add(new Polygon());
clip.get(0).add(190, 210);
clip.get(0).add(240, 210);
clip.get(0).add(240, 130);
clip.get(0).add(190, 130);

List<Polygon> solution = new ArrayList<Polygon>();

Clipper c = new Clipper();
c.addPolygons(subj, PolyType.ptSubject);
c.addPolygons(clip, PolyType.ptClip);
c.execute(ClipType.UNION, solution, PolyFillType.EVENODD, PolyFillType.EVENODD);