v6.4.2 (27 February 2017) Rev 512

Changelog:

• Several minor bugfixes: #152 #160 #161 #162 (see https://sourceforge.net/p/polyclipping/code/HEAD/tree/ )

v6.4 (2 July 2015) Rev 495

Changelog:

• Numerous generally minor bugfixes

v6.2.1 (31 October 2014) Rev 482

Changelog:

• Bugfix in ClipperOffset.Execute where the Polytree.IsHole property
  was returning incorrect values with negative offsets
• Very minor improvement to join rounding in ClipperOffset
• Fixed CPP OpenGL demo.

Also includes the following:
v6.2.0 (17 October 2014) Rev 477

• Numerous minor bugfixes, too many to list.
  (See revisions 454-475 in Sourceforge Repository)
• The ZFillFunction (custom callback function) has had its parameters
  changed.
• Curves demo removed (temporarily).
• Deprecated functions have been removed.

v6.1.5 (26 February 2014) Rev 460

• Improved the joining of output polygons sharing a common edge
  when those common edges are horizontal.
• Fixed a bug in ClipperOffset.AddPath() which would produce
  incorrect solutions when open paths were added before closed paths.
• Minor code tidy and performance improvement

v6.1.4 (6 February 2014)

• Fixed bugs in MinkowskiSum
• Fixed minor bug when using Clipper.ForceSimplify.
• Modified use_xyz callback so that all 4 vertices around an
  intersection point are now passed to the callback function.

v6.1.3a (22 January 2014) Rev 453

Changelog:

• Fixed buggy PointInPolygon function (C++ and C# only).
  Note this bug only affected the newly exported function, the
  internal PointInPolygon function used by Clipper was OK.

Also includes the following changes:
v6.1.3 (19 January 2014) Rev 452

• Fixed potential endless loop condition when adding open
  paths to Clipper.
• Fixed missing implementation of SimplifyPolygon function
  in C++ code.
• Fixed incorrect upper range constant for polygon coordinates
  in Delphi code.
• Added PointInPolygon function.
• Overloaded MinkowskiSum function to accommodate multi-contour
  paths.

v6.1.2 (15 December 2013) Rev 444

• Fixed broken C++ header file.
• Minor improvement to joining polygons.

v6.1.1 (13 December 2013) Rev 441

• Fixed a couple of bugs affecting open paths that could
  raise unhandled exceptions.

v6.1.0 (12 December 2013)

• Deleted: Previously deprecated code has been removed.
• Modified: The OffsetPaths function is now deprecated as it has
  been replaced by the ClipperOffset class which is much more
  flexible.
• Bugfixes: Several minor bugs have been fixed including
  occasionally an incorrect nesting within the PolyTree structure.

v6.0.0 (30 October 2013)

Changelog:

• Added: Open path (polyline) clipping. A new 'Curves' demo
  application showcases this (see the 'Curves' directory).
• Update: Major improvement in the merging of
  shared/collinear edges in clip solutions (see Execute).
• Added: The IntPoint structure now has an optional 'Z' member.
  (See the precompiler directive use_xyz.)
• Added: Users can now force Clipper to use 32bit integers
  (via the precompiler directive use_int32) instead of using
  64bit integers.
• Modified: To accommodate open paths, the Polygon and Polygons
  structures have been renamed Path and Paths respectively. The
  AddPolygon and AddPolygons methods of the ClipperBase class
  have been renamed AddPath and AddPaths respectively. Several
  other functions have been similarly renamed.
• Modified: The PolyNode Class has a new IsOpen property.
• Modified: The Clipper class has a new ZFillFunction property.
• Added: MinkowskiSum and MinkowskiDiff functions added.
• Added: Several other new functions have been added including
  PolyTreeToPaths, OpenPathsFromPolyTree and ClosedPathsFromPolyTree.
• Added: The Clipper constructor now accepts an optional InitOptions
  parameter to simplify setting properties.
• Bugfixes: Numerous minor bugs have been fixed.
• Deprecated: Version 6 is a major upgrade from previous versions
  and quite a number of changes have been made to exposed structures
  and functions. To minimize inconvenience to existing library users,
  some code has been retained and some added to maintain backward
  compatibility. However, because this code will be removed in a
  future update, it has been marked as deprecated and a precompiler
  directive use_deprecated has been defined.

v5.1.6 (23 May 2013)

Changelog:

• BugFix: CleanPolygon function was buggy.
• Changed: The behaviour of the 'miter' JoinType has been
  changed so that when squaring occurs, it's no longer
  extended up to the miter limit but is squared off at
  exactly 'delta' units. (This improves the look of mitering
  with larger limits at acute angles.)
• Added: New OffsetPolyLines function
• Update: Minor code refactoring and optimisations

Also includes the following:
v5.1.5 (5 May 2013)

• Added: ForceSimple property to Clipper class
• Update: Improved documentation

v5.1.4 (24 March 2013)

Changelog:

• Update: CleanPolygon function enhanced.
• Update: Documentation improved.