1 /*
2 SPDX-FileCopyrightText: 2010-2017 Angus Johnson <http://www.angusj.com>
3 SPDX-License-Identifier: MIT
4
5 Attributions:
6 The code in this library is an extension of Bala Vatti's clipping algorithm:
7 "A generic solution to polygon clipping"
8 Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63.
9 http://portal.acm.org/citation.cfm?id=129906
10
11 Computer graphics and geometric modeling: implementation and algorithms
12 By Max K. Agoston
13 Springer; 1 edition (January 4, 2005)
14 https://books.google.com/books?q=vatti+clipping+agoston
15
16 See also:
17 "Polygon Offsetting by Computing Winding Numbers"
18 Paper no. DETC2005-85513 pp. 565-575
19 ASME 2005 International Design Engineering Technical Conferences
20 and Computers and Information in Engineering Conference (IDETC/CIE2005)
21 September 24-28, 2005 , Long Beach, California, USA
22 https://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf
23
24 */
25
26 #ifndef clipper_hpp
27 #define clipper_hpp
28
29 #define CLIPPER_VERSION "6.4.2"
30
31 //use_int32: When enabled 32bit ints are used instead of 64bit ints. This
32 //improve performance but coordinate values are limited to the range +/- 46340
33 //#define use_int32
34
35 //use_xyz: adds a Z member to IntPoint. Adds a minor cost to performance.
36 //#define use_xyz
37
38 //use_lines: Enables line clipping. Adds a very minor cost to performance.
39 #define use_lines
40
41 //use_deprecated: Enables temporary support for the obsolete functions
42 //#define use_deprecated
43
44 #include <vector>
45 #include <list>
46 #include <set>
47 #include <stdexcept>
48 #include <cstring>
49 #include <cstdlib>
50 #include <ostream>
51 #include <functional>
52 #include <queue>
53
54 namespace ClipperLib {
55
56 enum ClipType { ctIntersection, ctUnion, ctDifference, ctXor };
57 enum PolyType { ptSubject, ptClip };
58 //By far the most widely used winding rules for polygon filling are
59 //EvenOdd & NonZero (GDI, GDI+, XLib, OpenGL, Cairo, AGG, Quartz, SVG, Gr32)
60 //Others rules include Positive, Negative and ABS_GTR_EQ_TWO (only in OpenGL)
61 //see https://glprogramming.com/red/chapter11.html
62 enum PolyFillType { pftEvenOdd, pftNonZero, pftPositive, pftNegative };
63
64 #ifdef use_int32
65 typedef int cInt;
66 static cInt const loRange = 0x7FFF;
67 static cInt const hiRange = 0x7FFF;
68 #else
69 using cInt = long long;
70 static cInt const loRange = 0x3FFFFFFF;
71 static cInt const hiRange = 0x3FFFFFFFFFFFFFFFLL;
72 using long64 = long long; //used by Int128 class
73 using ulong64 = unsigned long long;
74
75 #endif
76
77 struct IntPoint {
78 cInt X;
79 cInt Y;
80 #ifdef use_xyz
81 cInt Z;
IntPointClipperLib::IntPoint82 IntPoint(cInt x = 0, cInt y = 0, cInt z = 0): X(x), Y(y), Z(z) {};
83 #else
IntPointClipperLib::IntPoint84 IntPoint(cInt x = 0, cInt y = 0): X(x), Y(y) {};
85 #endif
86
operator ==(const IntPoint & a,const IntPoint & b)87 friend inline bool operator== (const IntPoint& a, const IntPoint& b)
88 {
89 return a.X == b.X && a.Y == b.Y;
90 }
operator !=(const IntPoint & a,const IntPoint & b)91 friend inline bool operator!= (const IntPoint& a, const IntPoint& b)
92 {
93 return a.X != b.X || a.Y != b.Y;
94 }
95 };
96 //------------------------------------------------------------------------------
97
98 using Path = std::vector<IntPoint>;
99 using Paths = std::vector<Path>;
100
operator <<(Path & poly,const IntPoint & p)101 inline Path& operator <<(Path& poly, const IntPoint& p) {poly.push_back(p); return poly;}
operator <<(Paths & polys,const Path & p)102 inline Paths& operator <<(Paths& polys, const Path& p) {polys.push_back(p); return polys;}
103
104 std::ostream& operator <<(std::ostream &s, const IntPoint &p);
105 std::ostream& operator <<(std::ostream &s, const Path &p);
106 std::ostream& operator <<(std::ostream &s, const Paths &p);
107
108 struct DoublePoint
109 {
110 double X;
111 double Y;
DoublePointClipperLib::DoublePoint112 DoublePoint(double x = 0, double y = 0) : X(x), Y(y) {}
DoublePointClipperLib::DoublePoint113 DoublePoint(IntPoint ip) : X((double)ip.X), Y((double)ip.Y) {}
114 };
115 //------------------------------------------------------------------------------
116
117 #ifdef use_xyz
118 typedef void (*ZFillCallback)(IntPoint& e1bot, IntPoint& e1top, IntPoint& e2bot, IntPoint& e2top, IntPoint& pt);
119 #endif
120
121 enum InitOptions {ioReverseSolution = 1, ioStrictlySimple = 2, ioPreserveCollinear = 4};
122 enum JoinType {jtSquare, jtRound, jtMiter};
123 enum EndType {etClosedPolygon, etClosedLine, etOpenButt, etOpenSquare, etOpenRound};
124
125 class PolyNode;
126 using PolyNodes = std::vector<PolyNode *>;
127
128 class PolyNode
129 {
130 public:
131 PolyNode();
~PolyNode()132 virtual ~PolyNode(){};
133 Path Contour;
134 PolyNodes Childs;
135 PolyNode* Parent;
136 PolyNode* GetNext() const;
137 bool IsHole() const;
138 bool IsOpen() const;
139 int ChildCount() const;
140 private:
141 unsigned Index; //node index in Parent.Childs
142 bool m_IsOpen;
143 JoinType m_jointype;
144 EndType m_endtype;
145 PolyNode* GetNextSiblingUp() const;
146 void AddChild(PolyNode& child);
147 friend class Clipper; //to access Index
148 friend class ClipperOffset;
149 };
150
151 class PolyTree: public PolyNode
152 {
153 public:
~PolyTree()154 ~PolyTree() override{Clear();};
155 PolyNode* GetFirst() const;
156 void Clear();
157 int Total() const;
158 private:
159 PolyNodes AllNodes;
160 friend class Clipper; //to access AllNodes
161 };
162
163 bool Orientation(const Path &poly);
164 double Area(const Path &poly);
165 int PointInPolygon(const IntPoint &pt, const Path &path);
166
167 void SimplifyPolygon(const Path &in_poly, Paths &out_polys, PolyFillType fillType = pftEvenOdd);
168 void SimplifyPolygons(const Paths &in_polys, Paths &out_polys, PolyFillType fillType = pftEvenOdd);
169 void SimplifyPolygons(Paths &polys, PolyFillType fillType = pftEvenOdd);
170
171 void CleanPolygon(const Path& in_poly, Path& out_poly, double distance = 1.415);
172 void CleanPolygon(Path& poly, double distance = 1.415);
173 void CleanPolygons(const Paths& in_polys, Paths& out_polys, double distance = 1.415);
174 void CleanPolygons(Paths& polys, double distance = 1.415);
175
176 void MinkowskiSum(const Path& pattern, const Path& path, Paths& solution, bool pathIsClosed);
177 void MinkowskiSum(const Path& pattern, const Paths& paths, Paths& solution, bool pathIsClosed);
178 void MinkowskiDiff(const Path& poly1, const Path& poly2, Paths& solution);
179
180 void PolyTreeToPaths(const PolyTree& polytree, Paths& paths);
181 void ClosedPathsFromPolyTree(const PolyTree& polytree, Paths& paths);
182 void OpenPathsFromPolyTree(PolyTree& polytree, Paths& paths);
183
184 void ReversePath(Path& p);
185 void ReversePaths(Paths& p);
186
187 struct IntRect { cInt left; cInt top; cInt right; cInt bottom; };
188
189 //enums that are used internally ...
190 enum EdgeSide { esLeft = 1, esRight = 2};
191
192 //forward declarations (for stuff used internally) ...
193 struct TEdge;
194 struct IntersectNode;
195 struct LocalMinimum;
196 struct OutPt;
197 struct OutRec;
198 struct Join;
199
200 using PolyOutList = std::vector<OutRec *>;
201 using EdgeList = std::vector<TEdge *>;
202 using JoinList = std::vector<Join *>;
203 using IntersectList = std::vector<IntersectNode *>;
204
205 //------------------------------------------------------------------------------
206
207 //ClipperBase is the ancestor to the Clipper class. It should not be
208 //instantiated directly. This class simply abstracts the conversion of sets of
209 //polygon coordinates into edge objects that are stored in a LocalMinima list.
210 class ClipperBase
211 {
212 public:
213 ClipperBase();
214 virtual ~ClipperBase();
215 virtual bool AddPath(const Path &pg, PolyType PolyTyp, bool Closed);
216 bool AddPaths(const Paths &ppg, PolyType PolyTyp, bool Closed);
217 virtual void Clear();
218 IntRect GetBounds();
PreserveCollinear()219 bool PreserveCollinear() {return m_PreserveCollinear;};
PreserveCollinear(bool value)220 void PreserveCollinear(bool value) {m_PreserveCollinear = value;};
221 protected:
222 void DisposeLocalMinimaList();
223 TEdge* AddBoundsToLML(TEdge *e, bool IsClosed);
224 virtual void Reset();
225 TEdge* ProcessBound(TEdge* E, bool IsClockwise);
226 void InsertScanbeam(const cInt Y);
227 bool PopScanbeam(cInt &Y);
228 bool LocalMinimaPending();
229 bool PopLocalMinima(cInt Y, const LocalMinimum *&locMin);
230 OutRec* CreateOutRec();
231 void DisposeAllOutRecs();
232 void DisposeOutRec(PolyOutList::size_type index);
233 void SwapPositionsInAEL(TEdge *edge1, TEdge *edge2);
234 void DeleteFromAEL(TEdge *e);
235 void UpdateEdgeIntoAEL(TEdge *&e);
236
237 using MinimaList = std::vector<LocalMinimum>;
238 MinimaList::iterator m_CurrentLM;
239 MinimaList m_MinimaList;
240
241 bool m_UseFullRange;
242 EdgeList m_edges;
243 bool m_PreserveCollinear;
244 bool m_HasOpenPaths;
245 PolyOutList m_PolyOuts;
246 TEdge *m_ActiveEdges;
247
248 using ScanbeamList = std::priority_queue<cInt>;
249 ScanbeamList m_Scanbeam;
250 };
251 //------------------------------------------------------------------------------
252
253 class Clipper : public virtual ClipperBase
254 {
255 public:
256 Clipper(int initOptions = 0);
257 bool Execute(ClipType clipType,
258 Paths &solution,
259 PolyFillType fillType = pftEvenOdd);
260 bool Execute(ClipType clipType,
261 Paths &solution,
262 PolyFillType subjFillType,
263 PolyFillType clipFillType);
264 bool Execute(ClipType clipType,
265 PolyTree &polytree,
266 PolyFillType fillType = pftEvenOdd);
267 bool Execute(ClipType clipType,
268 PolyTree &polytree,
269 PolyFillType subjFillType,
270 PolyFillType clipFillType);
ReverseSolution()271 bool ReverseSolution() { return m_ReverseOutput; };
ReverseSolution(bool value)272 void ReverseSolution(bool value) {m_ReverseOutput = value;};
StrictlySimple()273 bool StrictlySimple() {return m_StrictSimple;};
StrictlySimple(bool value)274 void StrictlySimple(bool value) {m_StrictSimple = value;};
275 //set the callback function for z value filling on intersections (otherwise Z is 0)
276 #ifdef use_xyz
277 void ZFillFunction(ZFillCallback zFillFunc);
278 #endif
279 protected:
280 virtual bool ExecuteInternal();
281 private:
282 JoinList m_Joins;
283 JoinList m_GhostJoins;
284 IntersectList m_IntersectList;
285 ClipType m_ClipType;
286 using MaximaList = std::list<cInt>;
287 MaximaList m_Maxima;
288 TEdge *m_SortedEdges;
289 bool m_ExecuteLocked;
290 PolyFillType m_ClipFillType;
291 PolyFillType m_SubjFillType;
292 bool m_ReverseOutput;
293 bool m_UsingPolyTree;
294 bool m_StrictSimple;
295 #ifdef use_xyz
296 ZFillCallback m_ZFill; //custom callback
297 #endif
298 void SetWindingCount(TEdge& edge);
299 bool IsEvenOddFillType(const TEdge& edge) const;
300 bool IsEvenOddAltFillType(const TEdge& edge) const;
301 void InsertLocalMinimaIntoAEL(const cInt botY);
302 void InsertEdgeIntoAEL(TEdge *edge, TEdge* startEdge);
303 void AddEdgeToSEL(TEdge *edge);
304 bool PopEdgeFromSEL(TEdge *&edge);
305 void CopyAELToSEL();
306 void DeleteFromSEL(TEdge *e);
307 void SwapPositionsInSEL(TEdge *edge1, TEdge *edge2);
308 bool IsContributing(const TEdge& edge) const;
309 bool IsTopHorz(const cInt XPos);
310 void DoMaxima(TEdge *e);
311 void ProcessHorizontals();
312 void ProcessHorizontal(TEdge *horzEdge);
313 void AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
314 OutPt* AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &pt);
315 OutRec* GetOutRec(int idx);
316 void AppendPolygon(TEdge *e1, TEdge *e2);
317 void IntersectEdges(TEdge *e1, TEdge *e2, IntPoint &pt);
318 OutPt* AddOutPt(TEdge *e, const IntPoint &pt);
319 OutPt* GetLastOutPt(TEdge *e);
320 bool ProcessIntersections(const cInt topY);
321 void BuildIntersectList(const cInt topY);
322 void ProcessIntersectList();
323 void ProcessEdgesAtTopOfScanbeam(const cInt topY);
324 void BuildResult(Paths& polys);
325 void BuildResult2(PolyTree& polytree);
326 void SetHoleState(TEdge *e, OutRec *outrec);
327 void DisposeIntersectNodes();
328 bool FixupIntersectionOrder();
329 void FixupOutPolygon(OutRec &outrec);
330 void FixupOutPolyline(OutRec &outrec);
331 bool IsHole(TEdge *e);
332 bool FindOwnerFromSplitRecs(OutRec &outRec, OutRec *&currOrfl);
333 void FixHoleLinkage(OutRec &outrec);
334 void AddJoin(OutPt *op1, OutPt *op2, const IntPoint offPt);
335 void ClearJoins();
336 void ClearGhostJoins();
337 void AddGhostJoin(OutPt *op, const IntPoint offPt);
338 bool JoinPoints(Join *j, OutRec* outRec1, OutRec* outRec2);
339 void JoinCommonEdges();
340 void DoSimplePolygons();
341 void FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec);
342 void FixupFirstLefts2(OutRec* InnerOutRec, OutRec* OuterOutRec);
343 void FixupFirstLefts3(OutRec* OldOutRec, OutRec* NewOutRec);
344 #ifdef use_xyz
345 void SetZ(IntPoint& pt, TEdge& e1, TEdge& e2);
346 #endif
347 };
348 //------------------------------------------------------------------------------
349
350 class ClipperOffset
351 {
352 public:
353 ClipperOffset(double miterLimit = 2.0, double roundPrecision = 0.25);
354 ~ClipperOffset();
355 void AddPath(const Path& path, JoinType joinType, EndType endType);
356 void AddPaths(const Paths& paths, JoinType joinType, EndType endType);
357 void Execute(Paths& solution, double delta);
358 void Execute(PolyTree& solution, double delta);
359 void Clear();
360 double MiterLimit;
361 double ArcTolerance;
362 private:
363 Paths m_destPolys;
364 Path m_srcPoly;
365 Path m_destPoly;
366 std::vector<DoublePoint> m_normals;
367 double m_delta, m_sinA, m_sin, m_cos;
368 double m_miterLim, m_StepsPerRad;
369 IntPoint m_lowest;
370 PolyNode m_polyNodes;
371
372 void FixOrientations();
373 void DoOffset(double delta);
374 void OffsetPoint(int j, int& k, JoinType jointype);
375 void DoSquare(int j, int k);
376 void DoMiter(int j, int k, double r);
377 void DoRound(int j, int k);
378 };
379 //------------------------------------------------------------------------------
380
381 class clipperException : public std::exception
382 {
383 public:
clipperException(const char * description)384 clipperException(const char* description): m_descr(description) {}
~clipperException()385 ~clipperException() throw() override {}
what() const386 const char* what() const throw() override {return m_descr.c_str();}
387 private:
388 std::string m_descr;
389 };
390 //------------------------------------------------------------------------------
391
392 } //ClipperLib namespace
393
394 #endif //clipper_hpp
395
396
397