Numerous minor bugfixes to ClipperOffset (#703)

CPP/Clipper2Lib/include/clipper2/clipper.core.h

@@ -1,6 +1,6 @@
 /*******************************************************************************
 * Author    :  Angus Johnson                                                   *
-* Date      :  4 October 2023                                                  *
+* Date      :  1 November 2023                                                 *
 * Website   :  http://www.angusj.com                                           *
 * Copyright :  Angus Johnson 2010-2023                                         *
 * Purpose   :  Core Clipper Library structures and functions                   *
@@ -19,7 +19,7 @@
 #include <algorithm>
 #include <climits>
 #include <numeric>
-#include "clipper.version.h"
+#include "clipper2/clipper.version.h"
 
 namespace Clipper2Lib
 {
@@ -229,6 +229,14 @@ namespace Clipper2Lib
   using Paths64 = std::vector< Path64>;
   using PathsD = std::vector< PathD>;
 
+  static const Point64 InvalidPoint64 = Point64(
+    (std::numeric_limits<int64_t>::max)(),
+    (std::numeric_limits<int64_t>::max)());
+  static const PointD InvalidPointD = PointD(
+    (std::numeric_limits<double>::max)(),
+    (std::numeric_limits<double>::max)());
+
+
   // Rect ------------------------------------------------------------------------
 
   template <typename T>
@@ -259,10 +267,12 @@ namespace Clipper2Lib
       else
       {
         left = top = (std::numeric_limits<T>::max)();
-        right = bottom = -(std::numeric_limits<int64_t>::max)();
+        right = bottom = (std::numeric_limits<T>::lowest)();
       }
     }
 
+    bool IsValid() const { return left != (std::numeric_limits<T>::max)(); }
+
     T Width() const { return right - left; }
     T Height() const { return bottom - top; }
     void Width(T width) { right = left + width; }
@@ -344,10 +354,16 @@ namespace Clipper2Lib
     return result;
   }
 
-  static const Rect64 MaxInvalidRect64 = Rect64(
-    INT64_MAX, INT64_MAX, INT64_MIN, INT64_MIN);
-  static const RectD MaxInvalidRectD = RectD(
-    MAX_DBL, MAX_DBL, -MAX_DBL, -MAX_DBL);
+  static const Rect64 InvalidRect64 = Rect64(
+    (std::numeric_limits<int64_t>::max)(), 
+    (std::numeric_limits<int64_t>::max)(), 
+    (std::numeric_limits<int64_t>::lowest)(),
+    (std::numeric_limits<int64_t>::lowest)());
+  static const RectD InvalidRectD = RectD(
+    (std::numeric_limits<double>::max)(),
+    (std::numeric_limits<double>::max)(),
+    (std::numeric_limits<double>::lowest)(),
+    (std::numeric_limits<double>::lowest)());
 
   template <typename T>
   Rect<T> GetBounds(const Path<T>& path)
@@ -549,7 +565,7 @@ namespace Clipper2Lib
   inline void StripDuplicates( Path<T>& path, bool is_closed_path)
   {
     //https://stackoverflow.com/questions/1041620/whats-the-most-efficient-way-to-erase-duplicates-and-sort-a-vector#:~:text=Let%27s%20compare%20three%20approaches%3A
-    path.erase(std::unique(path.begin(), path.end()),path.end());
+    path.erase(std::unique(path.begin(), path.end()), path.end());
     if (is_closed_path)
       while (path.size() > 1 && path.back() == path.front()) path.pop_back();
   }

CPP/Clipper2Lib/include/clipper2/clipper.engine.h

@@ -19,7 +19,7 @@
 #include <numeric>
 #include <memory>
 
-#include "clipper.core.h"
+#include "clipper2/clipper.core.h"
 
 namespace Clipper2Lib {
 

CPP/Clipper2Lib/include/clipper2/clipper.export.h

@@ -1,6 +1,6 @@
 /*******************************************************************************
 * Author    :  Angus Johnson                                                   *
-* Date      :  29 October 2023                                                 *
+* Date      :  1 November 2023                                                 *
 * Website   :  http://www.angusj.com                                           *
 * Copyright :  Angus Johnson 2010-2023                                         *
 * Purpose   :  This module exports the Clipper2 Library (ie DLL/so)            *
@@ -138,7 +138,6 @@ EXTERN_DLL_EXPORT void DisposeExportedCPolyTreeD(CPolyTreeD& p)
   delete[] p;
 }
 
-
 // Boolean clipping:
 // cliptype: None=0, Intersection=1, Union=2, Difference=3, Xor=4
 // fillrule: EvenOdd=0, NonZero=1, Positive=2, Negative=3
@@ -226,7 +225,7 @@ static void GetPolytreeCountAndCStorageSize(const PolyTree64& tree,
 template <typename T>
 static T* CreateCPaths(const Paths<T>& paths)
 {
-  size_t cnt, array_len;
+  size_t cnt = 0, array_len = 0;
   GetPathCountAndCPathsArrayLen(paths, cnt, array_len);
   T* result = new T[array_len], * v = result;
   *v++ = array_len;
@@ -496,13 +495,15 @@ EXTERN_DLL_EXPORT CPathsD InflatePathsD(const CPathsD paths,
   double arc_tolerance, bool reverse_solution)
 {
   if (precision < -8 || precision > 8 || !paths) return nullptr;
+
   const double scale = std::pow(10, precision);
   ClipperOffset clip_offset(miter_limit, arc_tolerance, reverse_solution);
   Paths64 pp = ConvertCPathsDToPaths64(paths, scale);
   clip_offset.AddPaths(pp, JoinType(jointype), EndType(endtype));
   Paths64 result;
   clip_offset.Execute(delta * scale, result);
-  return CreateCPathsDFromPaths64(result, 1/scale);
+
+  return CreateCPathsDFromPaths64(result, 1 / scale);
 }
 
 EXTERN_DLL_EXPORT CPaths64 RectClip64(const CRect64& rect, const CPaths64 paths)
@@ -526,7 +527,8 @@ EXTERN_DLL_EXPORT CPathsD RectClipD(const CRectD& rect, const CPathsD paths, int
   Paths64 pp = ConvertCPathsDToPaths64(paths, scale);
   class RectClip64 rc(rec);
   Paths64 result = rc.Execute(pp);
-  return CreateCPathsDFromPaths64(result, 1/scale);
+
+  return CreateCPathsDFromPaths64(result, 1 / scale);
 }
 
 EXTERN_DLL_EXPORT CPaths64 RectClipLines64(const CRect64& rect,
@@ -545,12 +547,13 @@ EXTERN_DLL_EXPORT CPathsD RectClipLinesD(const CRectD& rect,
 {
   if (CRectIsEmpty(rect) || !paths) return nullptr;
   if (precision < -8 || precision > 8) return nullptr;
+
   const double scale = std::pow(10, precision);
   Rect64 r = ScaleRect<int64_t, double>(CRectToRect(rect), scale);
   class RectClipLines64 rcl(r);
   Paths64 pp = ConvertCPathsDToPaths64(paths, scale);
   Paths64 result = rcl.Execute(pp);
-  return CreateCPathsDFromPaths64(result, 1/scale);
+  return CreateCPathsDFromPaths64(result, 1 / scale);
 }
 
 }  // end Clipper2Lib namespace

CPP/Clipper2Lib/include/clipper2/clipper.h

@@ -1,6 +1,6 @@
 /*******************************************************************************
 * Author    :  Angus Johnson                                                   *
-* Date      :  16 July 2023                                                    *
+* Date      :  1 November 2023                                                 *
 * Website   :  http://www.angusj.com                                           *
 * Copyright :  Angus Johnson 2010-2023                                         *
 * Purpose   :  This module provides a simple interface to the Clipper Library  *
@@ -14,11 +14,11 @@
 #include <type_traits>
 #include <vector>
 
-#include "clipper.core.h"
-#include "clipper.engine.h"
-#include "clipper.offset.h"
-#include "clipper.minkowski.h"
-#include "clipper.rectclip.h"
+#include "clipper2/clipper.core.h"
+#include "clipper2/clipper.engine.h"
+#include "clipper2/clipper.offset.h"
+#include "clipper2/clipper.minkowski.h"
+#include "clipper2/clipper.rectclip.h"
 
 namespace Clipper2Lib {
 
@@ -653,7 +653,7 @@ namespace Clipper2Lib {
   }
 
   template <typename T>
-  inline Path<T> SimplifyPath(const Path<T> path, 
+  inline Path<T> SimplifyPath(const Path<T> &path, 
     double epsilon, bool isClosedPath = true)
   {
     const size_t len = path.size(), high = len -1;
@@ -721,7 +721,7 @@ namespace Clipper2Lib {
   }
 
   template <typename T>
-  inline Paths<T> SimplifyPaths(const Paths<T> paths, 
+  inline Paths<T> SimplifyPaths(const Paths<T> &paths, 
     double epsilon, bool isClosedPath = true)
   {
     Paths<T> result;

CPP/Clipper2Lib/include/clipper2/clipper.minkowski.h

@@ -1,6 +1,6 @@
 /*******************************************************************************
 * Author    :  Angus Johnson                                                   *
-* Date      :  28 January 2023                                                 *
+* Date      :  1 November 2023                                                 *
 * Website   :  http://www.angusj.com                                           *
 * Copyright :  Angus Johnson 2010-2023                                         *
 * Purpose   :  Minkowski Sum and Difference                                    *
@@ -13,7 +13,7 @@
 #include <cstdlib>
 #include <vector>
 #include <string>
-#include "clipper.core.h"
+#include "clipper2/clipper.core.h"
 
 namespace Clipper2Lib 
 {

CPP/Clipper2Lib/include/clipper2/clipper.offset.h

@@ -1,6 +1,6 @@
 /*******************************************************************************
 * Author    :  Angus Johnson                                                   *
-* Date      :  24 September 2023                                               *
+* Date      :  5 November 2023                                                 *
 * Website   :  http://www.angusj.com                                           *
 * Copyright :  Angus Johnson 2010-2023                                         *
 * Purpose   :  Path Offset (Inflate/Shrink)                                    *
@@ -34,13 +34,12 @@ class ClipperOffset {
 	class Group {
 	public:
 		Paths64 paths_in;
-		Paths64 paths_out;
-		Path64 path;
+		std::vector<Rect64> bounds_list;
+		int lowest_path_idx = -1;
 		bool is_reversed = false;
 		JoinType join_type;
 		EndType end_type;
-		Group(const Paths64& _paths, JoinType _join_type, EndType _end_type) :
-			paths_in(_paths), join_type(_join_type), end_type(_end_type) {}
+		Group(const Paths64& _paths, JoinType _join_type, EndType _end_type);
 	};
 
 	int   error_code_ = 0;
@@ -51,6 +50,7 @@ class ClipperOffset {
 	double step_sin_ = 0.0;
 	double step_cos_ = 0.0;
 	PathD norms;
+	Path64 path_out;
 	Paths64 solution;
 	std::vector<Group> groups_;
 	JoinType join_type_ = JoinType::Bevel;
@@ -66,15 +66,17 @@ class ClipperOffset {
 #endif
 	DeltaCallback64 deltaCallback64_ = nullptr;
 
-	void DoBevel(Group& group, const Path64& path, size_t j, size_t k);
-	void DoSquare(Group& group, const Path64& path, size_t j, size_t k);
-	void DoMiter(Group& group, const Path64& path, size_t j, size_t k, double cos_a);
-	void DoRound(Group& group, const Path64& path, size_t j, size_t k, double angle);
+	size_t CalcSolutionCapacity();
+	bool CheckReverseOrientation();
+	void DoBevel(const Path64& path, size_t j, size_t k);
+	void DoSquare(const Path64& path, size_t j, size_t k);
+	void DoMiter(const Path64& path, size_t j, size_t k, double cos_a);
+	void DoRound(const Path64& path, size_t j, size_t k, double angle);
 	void BuildNormals(const Path64& path);
-	void OffsetPolygon(Group& group, Path64& path);
-	void OffsetOpenJoined(Group& group, Path64& path);
-	void OffsetOpenPath(Group& group, Path64& path);
-	void OffsetPoint(Group& group, Path64& path, size_t j, size_t k);
+	void OffsetPolygon(Group& group, const Path64& path);
+	void OffsetOpenJoined(Group& group, const Path64& path);
+	void OffsetOpenPath(Group& group, const Path64& path);
+	void OffsetPoint(Group& group, const Path64& path, size_t j, size_t k);
 	void DoGroupOffset(Group &group);
 	void ExecuteInternal(double delta);
 public:

CPP/Clipper2Lib/include/clipper2/clipper.rectclip.h

@@ -1,6 +1,6 @@
 /*******************************************************************************
 * Author    :  Angus Johnson                                                   *
-* Date      :  30 May 2023                                                     *
+* Date      :  1 November 2023                                                 *
 * Website   :  http://www.angusj.com                                           *
 * Copyright :  Angus Johnson 2010-2023                                         *
 * Purpose   :  FAST rectangular clipping                                       *
@@ -13,7 +13,7 @@
 #include <cstdlib>
 #include <vector>
 #include <queue>
-#include "clipper.core.h"
+#include "clipper2/clipper.core.h"
 
 namespace Clipper2Lib
 {

CPP/Clipper2Lib/src/clipper.engine.cpp

@@ -1,6 +1,6 @@
 /*******************************************************************************
 * Author    :  Angus Johnson                                                   *
-* Date      :  19 October 2023                                                 *
+* Date      :  1 November 2023                                                 *
 * Website   :  http://www.angusj.com                                           *
 * Copyright :  Angus Johnson 2010-2023                                         *
 * Purpose   :  This is the main polygon clipping module                        *
@@ -15,6 +15,7 @@
 #include <algorithm>
 
 #include "clipper2/clipper.engine.h"
+#include "clipper2/clipper.h"
 
 // https://github.com/AngusJohnson/Clipper2/discussions/334
 // #discussioncomment-4248602
@@ -2140,7 +2141,7 @@ namespace Clipper2Lib {
       horz_seg_list_.end(),
       [](HorzSegment& hs) { return UpdateHorzSegment(hs); });
     if (j < 2) return;
-    std::sort(horz_seg_list_.begin(), horz_seg_list_.end(), HorzSegSorter());
+    std::stable_sort(horz_seg_list_.begin(), horz_seg_list_.end(), HorzSegSorter());
 
     HorzSegmentList::iterator hs1 = horz_seg_list_.begin(), hs2;
     HorzSegmentList::iterator hs_end = hs1 +j;