The Clipper Library performs clipping, and offsetting of both lines and polygons.

A number of features set Clipper apart from other clipping libraries:

Current Version: 6.2.0

Author & copyright:
Angus Johnson. Copyright © 2010-2014
License, terms and conditions: Boost Software License


Distribution package contents:

The ZIP package contains the Clipper library's source code, a Windows CHM help file, HTML help, and a number of compiled demo applications (with full source code). The library was initially written in Delphi Pascal (and compiles with Delphi version 7 or above) but now contains C++, C# and Python translations too. The library's source code in each language is about 5000 lines. The Delphi code contains reasonably extensive comments, but comments are fewer in the C++ and C# code. The included sample applications show how Clipper can be used with the different languages using a number of graphics display libraries including - AGG, Cairo, OpenGL, Graphics32, GDI+ and SVG.

Download Link:



The Library is based on but significantly extends Bala Vatti's polygon clipping algorithm as described in "A generic solution to polygon clipping", Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63.

A section in "Computer graphics and geometric modeling: implementation and algorithms" by By Max K. Agoston (Springer, 2005) discussing Vatti Polygon Clipping was also helpful in creating the initial Clipper implementation.

The paper titled "Polygon Offsetting by Computing Winding Numbers" by Chen & McMains (Paper no. DETC2005-85513, ASME 2005. Pages 565-575) contains helpful discussion on the complexities of polygon offsetting together with some solutions.

See Also

Source, License, Clipper, ClipperOffset, ClipType, PolyFillType