Changes

The Clipper Library

Changes

  • v6.2.1 (31 October 2014)

    • Bugfix:

        Bugfix in ClipperOffset.Execute where the Polytree.IsHole property was returning incorrect values with negative offsets
    • Modified:

        Very minor improvement to join rounding in ClipperOffset
    • Bugfix:

        Fixed CPP OpenGL demo
  • v6.2.0 (26 September 2014)


    • Bugfix:

        Numerous minor bugfixes - too many to list. (See revisions 454-475 in Sourceforge Repository.)
    • Modified:

    • Modified:

        Deprecated functions have been removed.
    • Modified:

        The Curves demo has been temporarily removed. (It needs to be updated but that was holding up this latest release of the Clipper library.)
  • v6.1.3 (18 January 2014)


    • Bugfix:

        Fixed potential endless loop condition when adding open paths to Clipper.
    • Bugfix:

    • Bugfix:

        Fixed incorrect upper range constant for polygon coordinates in Delphi code.
    • Added:

    • Added:

        Overloaded MinkowskiSum function to accommodate multi-contour paths.
    • Modified:

        Documentation updated.
  • v6.1.2 (15 December 2013)


    • Bugfix:

        Fixed broken C++ header file.
    • Modified:

        Minor improvement to joining polygons.
  • v6.1.1 (13 December 2013)


    • Bugfix:

        Fixed a couple of bugs affecting open paths that could raise unhandled exceptions.
  • v6.1.0 (2 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        The OffsetPaths function is now deprecated as it has been replaced by the ClipperOffset class which is much more flexible.
    • Bugfix:

        Several minor bugs have been fixed including occasionally an incorrect nesting within the PolyTree structure.
  • v6.0.0 (30 October 2013)


    • Ver 6 is a MAJOR update that adds support for open path clipping.
    • 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. Using 32bit integers improves clipping performance by about 20-30%. (This has required the introduction of a new cInt integer type.) The trade-off to this speed up in performance is a very restricted vertex coordinate range of ± 46340.
    • 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 (to support open paths).
    • Bugfix:

        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)

    • BugFix:

    • Added:

        New OffsetPolyLines function. (Replaced with OffsetPaths function in ver 6.)
    • 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.)
    • Update:

        Minor code refactoring and optimisations.
  • v5.1.5 (5 May 2013)

    • Update:

        ForceSimple property added to the Clipper Class. (Renamed StrictlySimple in ver 6.)
    • Update:

        Further improvements to this documentation.
    • Update:

        Minor code optimisations and trivial bug fixes.
  • v5.1.4 (24 March 2013)

    • Update:

    • Update:

        Documentation improved.
  • v5.1.3 (12 March 2013)

    • Bugfix:

        Minor bug fixes.
    • Update:

        Documentation significantly improved.
  • v5.1.2 (26 February 2013)

    • Bugfix:

        PolyNode class was missing a constructor.
    • Update:

        The MiterLimit parameter in the OffsetPolygons function has been renamed Limit and can now also be used to limit the number of vertices used to construct arcs when JoinType is set to jtRound.
  • v5.1.0 (17 February 2013)

    • Update:

        ExPolygons has been replaced with the PolyTree / PolyNode classes to more fully represent the parent-child relationships of the polygons returned by Clipper's Execute method.
    • Added:

    • Bugfix:

        Another orientation bug fixed.
  • v5.0.2 (30 December 2012)

    • Bugfix:

        Significant fixes in and tidy of the internal Int128 class (which is used only when polygon coordinate values are greater than ±0x3FFFFFFF (~1.07e9)).
    • Update:

        The Area function has been updated with a faster algorithm.
    • Update:

        Documentation updates. The newish but undocumented 'CheckInputs' parameter of the OffsetPolygons function has been renamed 'AutoFix' and documented too. The comments on rounding have also been improved (ie clearer and expanded).
  • v4.10.0 (25 December 2012)

    • Bugfix:

        Orientation bugs should now be resolved (finally!).
    • Bugfix:

        Bug in Int128 class.
  • v4.9.8 (2 December 2012)

    • Bugfix:

        Further fixes to rare Orientation bug.
  • v4.9.7 (29 November 2012)

    • Bugfix:

        Bug that very rarely returned a wrong polygon orientation.
    • Bugfix:

        Obscure bug affecting OffsetPolygons when using jtRound for the JoinType parameter and when polygons also contain very large coordinate values.
  • v4.9.6 (9 November 2012)

    • Bugfix:

        Another obscure bug related to joining intersections.
  • v4.9.4 (2 November 2012)

    • Bugfix:

        Bugs in Int128 class occasionally causing wrong orientations.
    • Bugfix:

        Further fixes related to joining intersections.
  • v4.9.0 (9 October 2012)

    • Bugfix:

        Obscure bug related to joining intersections.
  • v4.8.9 (25 September 2012)

    • Bugfix:

        Obscure bug related to precision of intersections.
  • v4.8.8 (30 August 2012)

    • Bugfix:

        Fixed bug in OffsetPolygons function introduced in version 4.8.5.
  • v4.8.7 (24 August 2012)

    • Bugfix:

        ReversePolygon function in C++ translation was broken.
    • Bugfix:

        Two obscure bugs affecting orientation fixed too.
  • v4.8.6 (11 August 2012)

    • Bugfix:

        Potential for memory overflow errors when using ExPolygons structure.
    • Bugfix:

        The polygon coordinate range has been reduced to ± 0x3FFFFFFFFFFFFFFF (4.6e18).
    • Update:

        ReversePolygons function was misnamed ReversePoints in C++.
    • Update:

        SimplifyPolygon function now takes a PolyFillType parameter.
  • v4.8.5 (15 July 2012)

  • v4.8.4 (1 June 2012)

    • Bugfix:

        Another obscure bug affecting ExPolygons structure.
  • v4.8.3 (27 May 2012)

    • Bugfix:

        Obscure bug causing incorrect removal of a vertex.
  • v4.8.2 (21 May 2012)

    • Bugfix:

        Obscure bug could cause an exception when using ExPolygon structure.
  • v4.8.1 (12 May 2012)

    • Update:

        Code tidy and minor bug fixes.
  • v4.8.0 (30 April 2012)

    • Bugfix:

        Occasional errors in orientation fixed.
    • Update:

        Added notes on rounding to the documentation.
  • v4.7.6 (11 April 2012)

    • Bugfix:

        Fixed a bug in the Orientation function (affecting C# translations only).
    • Update:

        Minor documentation update.
  • v4.7.5 (28 March 2012)

    • Bugfix:

        Fixed a recently introduced bug that occasionally caused an unhandled exception in C++ and C# translations.
  • v4.7.1 (3 March 2012)

    • Bugfix:

        Rare crash when JoinCommonEdges joined polygons that 'cancelled' each other.
    • Bugfix:

        Clipper's internal Orientation method occasionally returned wrong result.
    • Update:

        Improved C# code (thanks to numerous suggestions from David Piepgrass)
  • v4.7 (10 February 2012)

    • Update:

        Improved the joining of output polygons sharing a common edge.
  • v4.6.4 (8 December 2011)

  • v4.6 (29 October 2011)

    • Added:

        Support for Positive and Negative polygon fill types (in addition to the EvenOdd and NonZero fill types).
    • Bugfix:

        The OffsetPolygons function was generating the occasional artefact when 'shrinking' polygons.
  • v4.5.5 (6 October 2011)

    • Bugfix:

        Fixed an obscure bug in Clipper's JoinCommonEdges method.
    • Update:

        Replaced IsClockwise function with Orientation function. The orientation issues affecting OffsetPolygons should finally be resolved.
    • Change:

        The Area function once again returns the signed area.
  • v4.4.0 (6 August 2011)

    • BugFix:

        A number of minor bugfixes that mostly affected the new ExPolygons structure.
  • v4.3.0 (17 June 2011)

    • Added:

        ExPolygons structure that explicitly associates 'hole' polygons with their 'outer' container polygons.
    • Added:

        Execute method now overloaded so the solution parameter can be either Polygons or ExPolygons.
    • Bug fix:

        Fixed a rare bug in the orientation of solution polygons.
  • v4.2.4 (26 April 2011)

    • Update:

        Input polygon coordinates can now contain the full range of signed 64bit integers (ie +/-9,223,372,036,854,775,807). This means that floating point values can be converted to and from Clipper's 64bit vertex structure (IntPoint) and still retain a precision of up to 18 decimal places. However, since the large-integer math that supports this expanded range imposes a small cost on performance (~15%), a new property UseFullCoordinateRange has been added to the Clipper class to allow users the choice of whether or not to use this expanded coordinate range. If this property is disabled, coordinate values are restricted to +/-1,500,000,000. (By default, this property is enabled.)
  • v4.0 (4 April 2011)

    • Major update:

        Clipper is a major rewrite of earlier versions. The biggest change is that floating point values are no longer used, except for the storing of edge slope values. The main benefit of this is the issue of numerical robustness has been addressed. Due to other major code improvements Clipper v4 is approximately 40% faster than Clipper v3.
    • Changes:

        The AddPolyPolygon method has been renamed to AddPolygons, and the IgnoreOrientation property has been removed. The clipper_misc library has been merged back into the clipper library.
  • v2.8 (20 November 2010)

    • Updated:

        Output polygons which previously shared a common edge are now merged.
    • Added:

        Added support module for Cairo Graphics Library (with accompanying demo).
    • Added:

        Added C# and C++ demos.
  • v2.522 (15 October 2010)

    • Added:

        Added C# translation (thanks to Olivier Lejeune) and a link to Ruby bindings (thanks to Mike Owens).
  • v2.0 (31 July 2010)

    • Major update:

        Clipper now processes polygons using both the Even-Odd (alternate) and Non-Zero (winding) filling rules.
  • v1.4c (16 June 2010)

    • Additions:

        Added Delphi and C++ units to support the AGG graphics library
  • v1.2s (2 June 2010)

    • Additions:

        C++ translation of Delphi code
  • v1.0 (9 May 2010) - Initial public release

See Also

Deprecated, Rounding, Clipper.Constructor, Clipper.Execute, Clipper.ZFillFunction, ClipperBase.AddPath, ClipperBase.AddPaths, ClipperOffset, ClipperOffset.Execute, PolyNode, PolyTree, Area, CleanPolygon, CleanPolygons, ClosedPathsFromPolyTree, MinkowskiDiff, MinkowskiSum, OffsetPaths, OpenPathsFromPolyTree, Orientation, PointInPolygon, PolyTreeToPaths, SimplifyPolygon, SimplifyPolygons, Defines, CInt, InitOptions, IntPoint, Path, Paths, PolyFillType, ZFillCallback