1/*******************************************************************************
2* *
3* Author : Angus Johnson *
4* Version : 6.4.2 *
5* Date : 27 February 2017 *
6* Website : http://www.angusj.com *
7* Copyright : Angus Johnson 2010-2017 *
8* *
9* License: *
10* Use, modification & distribution is subject to Boost Software License Ver 1. *
11* http://www.boost.org/LICENSE_1_0.txt *
12* *
13* Attributions: *
14* The code in this library is an extension of Bala Vatti's clipping algorithm: *
15* "A generic solution to polygon clipping" *
16* Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63. *
17* http://portal.acm.org/citation.cfm?id=129906 *
18* *
19* Computer graphics and geometric modeling: implementation and algorithms *
20* By Max K. Agoston *
21* Springer; 1 edition (January 4, 2005) *
22* http://books.google.com/books?q=vatti+clipping+agoston *
23* *
24* See also: *
25* "Polygon Offsetting by Computing Winding Numbers" *
26* Paper no. DETC2005-85513 pp. 565-575 *
27* ASME 2005 International Design Engineering Technical Conferences *
28* and Computers and Information in Engineering Conference (IDETC/CIE2005) *
29* September 24-28, 2005 , Long Beach, California, USA *
30* http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf *
31* *
32*******************************************************************************/
33
34/*******************************************************************************
35* *
36* This is a translation of the Delphi Clipper library and the naming style *
37* used has retained a Delphi flavour. *
38* *
39*******************************************************************************/
40
41#include "clipper.hpp"
42#include <cmath>
43#include <vector>
44#include <algorithm>
45#include <stdexcept>
46#include <cstring>
47#include <cstdlib>
48#include <ostream>
49#include <functional>
50
51//Explicitly disables exceptions handling for target platform
52//#define CLIPPER_NOEXCEPTION
53
54#define CLIPPER_THROW(exception) std::abort()
55#define CLIPPER_TRY if(true)
56#define CLIPPER_CATCH(exception) if(false)
57
58#if defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)
59 #ifndef CLIPPER_NOEXCEPTION
60 #undef CLIPPER_THROW
61 #define CLIPPER_THROW(exception) throw exception
62 #undef CLIPPER_TRY
63 #define CLIPPER_TRY try
64 #undef CLIPPER_CATCH
65 #define CLIPPER_CATCH(exception) catch(exception)
66 #endif
67#endif
68
69//Optionally allows to override exception macros
70#if defined(CLIPPER_THROW_USER)
71 #undef CLIPPER_THROW
72 #define CLIPPER_THROW CLIPPER_THROW_USER
73#endif
74#if defined(CLIPPER_TRY_USER)
75 #undef CLIPPER_TRY
76 #define CLIPPER_TRY CLIPPER_TRY_USER
77#endif
78#if defined(CLIPPER_CATCH_USER)
79 #undef CLIPPER_CATCH
80 #define CLIPPER_CATCH CLIPPER_CATCH_USER
81#endif
82
83namespace ClipperLib {
84
85static double const pi = 3.141592653589793238;
86static double const two_pi = pi *2;
87static double const def_arc_tolerance = 0.25;
88
89enum Direction { dRightToLeft, dLeftToRight };
90
91static int const Unassigned = -1; //edge not currently 'owning' a solution
92static int const Skip = -2; //edge that would otherwise close a path
93
94#define HORIZONTAL (-1.0E+40)
95#define TOLERANCE (1.0e-20)
96#define NEAR_ZERO(val) (((val) > -TOLERANCE) && ((val) < TOLERANCE))
97
98struct TEdge {
99 IntPoint Bot;
100 IntPoint Curr; //current (updated for every new scanbeam)
101 IntPoint Top;
102 double Dx;
103 PolyType PolyTyp;
104 EdgeSide Side; //side only refers to current side of solution poly
105 int WindDelta; //1 or -1 depending on winding direction
106 int WindCnt;
107 int WindCnt2; //winding count of the opposite polytype
108 int OutIdx;
109 TEdge *Next;
110 TEdge *Prev;
111 TEdge *NextInLML;
112 TEdge *NextInAEL;
113 TEdge *PrevInAEL;
114 TEdge *NextInSEL;
115 TEdge *PrevInSEL;
116};
117
118struct IntersectNode {
119 TEdge *Edge1;
120 TEdge *Edge2;
121 IntPoint Pt;
122};
123
124struct LocalMinimum {
125 cInt Y;
126 TEdge *LeftBound;
127 TEdge *RightBound;
128};
129
130struct OutPt;
131
132//OutRec: contains a path in the clipping solution. Edges in the AEL will
133//carry a pointer to an OutRec when they are part of the clipping solution.
134struct OutRec {
135 int Idx;
136 bool IsHole;
137 bool IsOpen;
138 OutRec *FirstLeft; //see comments in clipper.pas
139 PolyNode *PolyNd;
140 OutPt *Pts;
141 OutPt *BottomPt;
142};
143
144struct OutPt {
145 int Idx;
146 IntPoint Pt;
147 OutPt *Next;
148 OutPt *Prev;
149};
150
151struct Join {
152 OutPt *OutPt1;
153 OutPt *OutPt2;
154 IntPoint OffPt;
155};
156
157struct LocMinSorter
158{
159 inline bool operator()(const LocalMinimum& locMin1, const LocalMinimum& locMin2)
160 {
161 return locMin2.Y < locMin1.Y;
162 }
163};
164
165//------------------------------------------------------------------------------
166//------------------------------------------------------------------------------
167
168inline cInt Round(double val)
169{
170 if ((val < 0)) return static_cast<cInt>(val - 0.5);
171 else return static_cast<cInt>(val + 0.5);
172}
173//------------------------------------------------------------------------------
174
175inline cInt Abs(cInt val)
176{
177 return val < 0 ? -val : val;
178}
179
180//------------------------------------------------------------------------------
181// PolyTree methods ...
182//------------------------------------------------------------------------------
183
184void PolyTree::Clear()
185{
186 for (PolyNodes::size_type i = 0; i < AllNodes.size(); ++i)
187 delete AllNodes[i];
188 AllNodes.resize(0);
189 Childs.resize(0);
190}
191//------------------------------------------------------------------------------
192
193PolyNode* PolyTree::GetFirst() const
194{
195 if (!Childs.empty())
196 return Childs[0];
197 else
198 return 0;
199}
200//------------------------------------------------------------------------------
201
202int PolyTree::Total() const
203{
204 int result = (int)AllNodes.size();
205 //with negative offsets, ignore the hidden outer polygon ...
206 if (result > 0 && Childs[0] != AllNodes[0]) result--;
207 return result;
208}
209
210//------------------------------------------------------------------------------
211// PolyNode methods ...
212//------------------------------------------------------------------------------
213
214PolyNode::PolyNode(): Parent(0), Index(0), m_IsOpen(false)
215{
216}
217//------------------------------------------------------------------------------
218
219int PolyNode::ChildCount() const
220{
221 return (int)Childs.size();
222}
223//------------------------------------------------------------------------------
224
225void PolyNode::AddChild(PolyNode& child)
226{
227 unsigned cnt = (unsigned)Childs.size();
228 Childs.push_back(&child);
229 child.Parent = this;
230 child.Index = cnt;
231}
232//------------------------------------------------------------------------------
233
234PolyNode* PolyNode::GetNext() const
235{
236 if (!Childs.empty())
237 return Childs[0];
238 else
239 return GetNextSiblingUp();
240}
241//------------------------------------------------------------------------------
242
243PolyNode* PolyNode::GetNextSiblingUp() const
244{
245 if (!Parent) //protects against PolyTree.GetNextSiblingUp()
246 return 0;
247 else if (Index == Parent->Childs.size() - 1)
248 return Parent->GetNextSiblingUp();
249 else
250 return Parent->Childs[Index + 1];
251}
252//------------------------------------------------------------------------------
253
254bool PolyNode::IsHole() const
255{
256 bool result = true;
257 PolyNode* node = Parent;
258 while (node)
259 {
260 result = !result;
261 node = node->Parent;
262 }
263 return result;
264}
265//------------------------------------------------------------------------------
266
267bool PolyNode::IsOpen() const
268{
269 return m_IsOpen;
270}
271//------------------------------------------------------------------------------
272
273#ifndef use_int32
274
275//------------------------------------------------------------------------------
276// Int128 class (enables safe math on signed 64bit integers)
277// eg Int128 val1((long64)9223372036854775807); //ie 2^63 -1
278// Int128 val2((long64)9223372036854775807);
279// Int128 val3 = val1 * val2;
280// val3.AsString => "85070591730234615847396907784232501249" (8.5e+37)
281//------------------------------------------------------------------------------
282
283class Int128
284{
285 public:
286 ulong64 lo;
287 long64 hi;
288
289 Int128(long64 _lo = 0)
290 {
291 lo = (ulong64)_lo;
292 if (_lo < 0) hi = -1; else hi = 0;
293 }
294
295
296 Int128(const Int128 &val): lo(val.lo), hi(val.hi){}
297
298 Int128(const long64& _hi, const ulong64& _lo): lo(_lo), hi(_hi){}
299
300 Int128& operator = (const long64 &val)
301 {
302 lo = (ulong64)val;
303 if (val < 0) hi = -1; else hi = 0;
304 return *this;
305 }
306
307 bool operator == (const Int128 &val) const
308 {return (hi == val.hi && lo == val.lo);}
309
310 bool operator != (const Int128 &val) const
311 { return !(*this == val);}
312
313 bool operator > (const Int128 &val) const
314 {
315 if (hi != val.hi)
316 return hi > val.hi;
317 else
318 return lo > val.lo;
319 }
320
321 bool operator < (const Int128 &val) const
322 {
323 if (hi != val.hi)
324 return hi < val.hi;
325 else
326 return lo < val.lo;
327 }
328
329 bool operator >= (const Int128 &val) const
330 { return !(*this < val);}
331
332 bool operator <= (const Int128 &val) const
333 { return !(*this > val);}
334
335 Int128& operator += (const Int128 &rhs)
336 {
337 hi += rhs.hi;
338 lo += rhs.lo;
339 if (lo < rhs.lo) hi++;
340 return *this;
341 }
342
343 Int128 operator + (const Int128 &rhs) const
344 {
345 Int128 result(*this);
346 result+= rhs;
347 return result;
348 }
349
350 Int128& operator -= (const Int128 &rhs)
351 {
352 *this += -rhs;
353 return *this;
354 }
355
356 Int128 operator - (const Int128 &rhs) const
357 {
358 Int128 result(*this);
359 result -= rhs;
360 return result;
361 }
362
363 Int128 operator-() const //unary negation
364 {
365 if (lo == 0)
366 return Int128(-hi, 0);
367 else
368 return Int128(~hi, ~lo + 1);
369 }
370
371 operator double() const
372 {
373 const double shift64 = 18446744073709551616.0; //2^64
374 if (hi < 0)
375 {
376 if (lo == 0) return (double)hi * shift64;
377 else return -(double)(~lo + ~hi * shift64);
378 }
379 else
380 return (double)(lo + hi * shift64);
381 }
382
383};
384//------------------------------------------------------------------------------
385
386Int128 Int128Mul (long64 lhs, long64 rhs)
387{
388 bool negate = (lhs < 0) != (rhs < 0);
389
390 if (lhs < 0) lhs = -lhs;
391 ulong64 int1Hi = ulong64(lhs) >> 32;
392 ulong64 int1Lo = ulong64(lhs & 0xFFFFFFFF);
393
394 if (rhs < 0) rhs = -rhs;
395 ulong64 int2Hi = ulong64(rhs) >> 32;
396 ulong64 int2Lo = ulong64(rhs & 0xFFFFFFFF);
397
398 //nb: see comments in clipper.pas
399 ulong64 a = int1Hi * int2Hi;
400 ulong64 b = int1Lo * int2Lo;
401 ulong64 c = int1Hi * int2Lo + int1Lo * int2Hi;
402
403 Int128 tmp;
404 tmp.hi = long64(a + (c >> 32));
405 tmp.lo = long64(c << 32);
406 tmp.lo += long64(b);
407 if (tmp.lo < b) tmp.hi++;
408 if (negate) tmp = -tmp;
409 return tmp;
410};
411#endif
412
413//------------------------------------------------------------------------------
414// Miscellaneous global functions
415//------------------------------------------------------------------------------
416
417bool Orientation(const Path &poly)
418{
419 return Area(poly) >= 0;
420}
421//------------------------------------------------------------------------------
422
423double Area(const Path &poly)
424{
425 int size = (int)poly.size();
426 if (size < 3) return 0;
427
428 double a = 0;
429 for (int i = 0, j = size -1; i < size; ++i)
430 {
431 a += ((double)poly[j].X + poly[i].X) * ((double)poly[j].Y - poly[i].Y);
432 j = i;
433 }
434 return -a * 0.5;
435}
436//------------------------------------------------------------------------------
437
438double Area(const OutPt *op)
439{
440 const OutPt *startOp = op;
441 if (!op) return 0;
442 double a = 0;
443 do {
444 a += (double)(op->Prev->Pt.X + op->Pt.X) * (double)(op->Prev->Pt.Y - op->Pt.Y);
445 op = op->Next;
446 } while (op != startOp);
447 return a * 0.5;
448}
449//------------------------------------------------------------------------------
450
451double Area(const OutRec &outRec)
452{
453 return Area(outRec.Pts);
454}
455//------------------------------------------------------------------------------
456
457bool PointIsVertex(const IntPoint &Pt, OutPt *pp)
458{
459 OutPt *pp2 = pp;
460 do
461 {
462 if (pp2->Pt == Pt) return true;
463 pp2 = pp2->Next;
464 }
465 while (pp2 != pp);
466 return false;
467}
468//------------------------------------------------------------------------------
469
470//See "The Point in Polygon Problem for Arbitrary Polygons" by Hormann & Agathos
471//http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf
472int PointInPolygon(const IntPoint &pt, const Path &path)
473{
474 //returns 0 if false, +1 if true, -1 if pt ON polygon boundary
475 int result = 0;
476 size_t cnt = path.size();
477 if (cnt < 3) return 0;
478 IntPoint ip = path[0];
479 for(size_t i = 1; i <= cnt; ++i)
480 {
481 IntPoint ipNext = (i == cnt ? path[0] : path[i]);
482 if (ipNext.Y == pt.Y)
483 {
484 if ((ipNext.X == pt.X) || (ip.Y == pt.Y &&
485 ((ipNext.X > pt.X) == (ip.X < pt.X)))) return -1;
486 }
487 if ((ip.Y < pt.Y) != (ipNext.Y < pt.Y))
488 {
489 if (ip.X >= pt.X)
490 {
491 if (ipNext.X > pt.X) result = 1 - result;
492 else
493 {
494 double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) -
495 (double)(ipNext.X - pt.X) * (ip.Y - pt.Y);
496 if (!d) return -1;
497 if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result;
498 }
499 } else
500 {
501 if (ipNext.X > pt.X)
502 {
503 double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) -
504 (double)(ipNext.X - pt.X) * (ip.Y - pt.Y);
505 if (!d) return -1;
506 if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result;
507 }
508 }
509 }
510 ip = ipNext;
511 }
512 return result;
513}
514//------------------------------------------------------------------------------
515
516int PointInPolygon (const IntPoint &pt, OutPt *op)
517{
518 //returns 0 if false, +1 if true, -1 if pt ON polygon boundary
519 int result = 0;
520 OutPt* startOp = op;
521 for(;;)
522 {
523 if (op->Next->Pt.Y == pt.Y)
524 {
525 if ((op->Next->Pt.X == pt.X) || (op->Pt.Y == pt.Y &&
526 ((op->Next->Pt.X > pt.X) == (op->Pt.X < pt.X)))) return -1;
527 }
528 if ((op->Pt.Y < pt.Y) != (op->Next->Pt.Y < pt.Y))
529 {
530 if (op->Pt.X >= pt.X)
531 {
532 if (op->Next->Pt.X > pt.X) result = 1 - result;
533 else
534 {
535 double d = (double)(op->Pt.X - pt.X) * (op->Next->Pt.Y - pt.Y) -
536 (double)(op->Next->Pt.X - pt.X) * (op->Pt.Y - pt.Y);
537 if (!d) return -1;
538 if ((d > 0) == (op->Next->Pt.Y > op->Pt.Y)) result = 1 - result;
539 }
540 } else
541 {
542 if (op->Next->Pt.X > pt.X)
543 {
544 double d = (double)(op->Pt.X - pt.X) * (op->Next->Pt.Y - pt.Y) -
545 (double)(op->Next->Pt.X - pt.X) * (op->Pt.Y - pt.Y);
546 if (!d) return -1;
547 if ((d > 0) == (op->Next->Pt.Y > op->Pt.Y)) result = 1 - result;
548 }
549 }
550 }
551 op = op->Next;
552 if (startOp == op) break;
553 }
554 return result;
555}
556//------------------------------------------------------------------------------
557
558bool Poly2ContainsPoly1(OutPt *OutPt1, OutPt *OutPt2)
559{
560 OutPt* op = OutPt1;
561 do
562 {
563 //nb: PointInPolygon returns 0 if false, +1 if true, -1 if pt on polygon
564 int res = PointInPolygon(op->Pt, OutPt2);
565 if (res >= 0) return res > 0;
566 op = op->Next;
567 }
568 while (op != OutPt1);
569 return true;
570}
571//----------------------------------------------------------------------
572
573bool SlopesEqual(const TEdge &e1, const TEdge &e2, bool UseFullInt64Range)
574{
575#ifndef use_int32
576 if (UseFullInt64Range)
577 return Int128Mul(e1.Top.Y - e1.Bot.Y, e2.Top.X - e2.Bot.X) ==
578 Int128Mul(e1.Top.X - e1.Bot.X, e2.Top.Y - e2.Bot.Y);
579 else
580#endif
581 return (e1.Top.Y - e1.Bot.Y) * (e2.Top.X - e2.Bot.X) ==
582 (e1.Top.X - e1.Bot.X) * (e2.Top.Y - e2.Bot.Y);
583}
584//------------------------------------------------------------------------------
585
586bool SlopesEqual(const IntPoint pt1, const IntPoint pt2,
587 const IntPoint pt3, bool UseFullInt64Range)
588{
589#ifndef use_int32
590 if (UseFullInt64Range)
591 return Int128Mul(pt1.Y-pt2.Y, pt2.X-pt3.X) == Int128Mul(pt1.X-pt2.X, pt2.Y-pt3.Y);
592 else
593#endif
594 return (pt1.Y-pt2.Y)*(pt2.X-pt3.X) == (pt1.X-pt2.X)*(pt2.Y-pt3.Y);
595}
596//------------------------------------------------------------------------------
597
598bool SlopesEqual(const IntPoint pt1, const IntPoint pt2,
599 const IntPoint pt3, const IntPoint pt4, bool UseFullInt64Range)
600{
601#ifndef use_int32
602 if (UseFullInt64Range)
603 return Int128Mul(pt1.Y-pt2.Y, pt3.X-pt4.X) == Int128Mul(pt1.X-pt2.X, pt3.Y-pt4.Y);
604 else
605#endif
606 return (pt1.Y-pt2.Y)*(pt3.X-pt4.X) == (pt1.X-pt2.X)*(pt3.Y-pt4.Y);
607}
608//------------------------------------------------------------------------------
609
610inline bool IsHorizontal(TEdge &e)
611{
612 return e.Dx == HORIZONTAL;
613}
614//------------------------------------------------------------------------------
615
616inline double GetDx(const IntPoint pt1, const IntPoint pt2)
617{
618 return (pt1.Y == pt2.Y) ?
619 HORIZONTAL : (double)(pt2.X - pt1.X) / (pt2.Y - pt1.Y);
620}
621//---------------------------------------------------------------------------
622
623inline void SetDx(TEdge &e)
624{
625 cInt dy = (e.Top.Y - e.Bot.Y);
626 if (dy == 0) e.Dx = HORIZONTAL;
627 else e.Dx = (double)(e.Top.X - e.Bot.X) / dy;
628}
629//---------------------------------------------------------------------------
630
631inline void SwapSides(TEdge &Edge1, TEdge &Edge2)
632{
633 EdgeSide Side = Edge1.Side;
634 Edge1.Side = Edge2.Side;
635 Edge2.Side = Side;
636}
637//------------------------------------------------------------------------------
638
639inline void SwapPolyIndexes(TEdge &Edge1, TEdge &Edge2)
640{
641 int OutIdx = Edge1.OutIdx;
642 Edge1.OutIdx = Edge2.OutIdx;
643 Edge2.OutIdx = OutIdx;
644}
645//------------------------------------------------------------------------------
646
647inline cInt TopX(TEdge &edge, const cInt currentY)
648{
649 return ( currentY == edge.Top.Y ) ?
650 edge.Top.X : edge.Bot.X + Round(edge.Dx *(currentY - edge.Bot.Y));
651}
652//------------------------------------------------------------------------------
653
654void IntersectPoint(TEdge &Edge1, TEdge &Edge2, IntPoint &ip)
655{
656#ifdef use_xyz
657 ip.Z = 0;
658#endif
659
660 double b1, b2;
661 if (Edge1.Dx == Edge2.Dx)
662 {
663 ip.Y = Edge1.Curr.Y;
664 ip.X = TopX(Edge1, ip.Y);
665 return;
666 }
667 else if (Edge1.Dx == 0)
668 {
669 ip.X = Edge1.Bot.X;
670 if (IsHorizontal(Edge2))
671 ip.Y = Edge2.Bot.Y;
672 else
673 {
674 b2 = Edge2.Bot.Y - (Edge2.Bot.X / Edge2.Dx);
675 ip.Y = Round(ip.X / Edge2.Dx + b2);
676 }
677 }
678 else if (Edge2.Dx == 0)
679 {
680 ip.X = Edge2.Bot.X;
681 if (IsHorizontal(Edge1))
682 ip.Y = Edge1.Bot.Y;
683 else
684 {
685 b1 = Edge1.Bot.Y - (Edge1.Bot.X / Edge1.Dx);
686 ip.Y = Round(ip.X / Edge1.Dx + b1);
687 }
688 }
689 else
690 {
691 b1 = Edge1.Bot.X - Edge1.Bot.Y * Edge1.Dx;
692 b2 = Edge2.Bot.X - Edge2.Bot.Y * Edge2.Dx;
693 double q = (b2-b1) / (Edge1.Dx - Edge2.Dx);
694 ip.Y = Round(q);
695 if (std::fabs(Edge1.Dx) < std::fabs(Edge2.Dx))
696 ip.X = Round(Edge1.Dx * q + b1);
697 else
698 ip.X = Round(Edge2.Dx * q + b2);
699 }
700
701 if (ip.Y < Edge1.Top.Y || ip.Y < Edge2.Top.Y)
702 {
703 if (Edge1.Top.Y > Edge2.Top.Y)
704 ip.Y = Edge1.Top.Y;
705 else
706 ip.Y = Edge2.Top.Y;
707 if (std::fabs(Edge1.Dx) < std::fabs(Edge2.Dx))
708 ip.X = TopX(Edge1, ip.Y);
709 else
710 ip.X = TopX(Edge2, ip.Y);
711 }
712 //finally, don't allow 'ip' to be BELOW curr.Y (ie bottom of scanbeam) ...
713 if (ip.Y > Edge1.Curr.Y)
714 {
715 ip.Y = Edge1.Curr.Y;
716 //use the more vertical edge to derive X ...
717 if (std::fabs(Edge1.Dx) > std::fabs(Edge2.Dx))
718 ip.X = TopX(Edge2, ip.Y); else
719 ip.X = TopX(Edge1, ip.Y);
720 }
721}
722//------------------------------------------------------------------------------
723
724void ReversePolyPtLinks(OutPt *pp)
725{
726 if (!pp) return;
727 OutPt *pp1, *pp2;
728 pp1 = pp;
729 do {
730 pp2 = pp1->Next;
731 pp1->Next = pp1->Prev;
732 pp1->Prev = pp2;
733 pp1 = pp2;
734 } while( pp1 != pp );
735}
736//------------------------------------------------------------------------------
737
738void DisposeOutPts(OutPt*& pp)
739{
740 if (pp == 0) return;
741 pp->Prev->Next = 0;
742 while( pp )
743 {
744 OutPt *tmpPp = pp;
745 pp = pp->Next;
746 delete tmpPp;
747 }
748}
749//------------------------------------------------------------------------------
750
751inline void InitEdge(TEdge* e, TEdge* eNext, TEdge* ePrev, const IntPoint& Pt)
752{
753 std::memset(e, 0, sizeof(TEdge));
754 e->Next = eNext;
755 e->Prev = ePrev;
756 e->Curr = Pt;
757 e->OutIdx = Unassigned;
758}
759//------------------------------------------------------------------------------
760
761void InitEdge2(TEdge& e, PolyType Pt)
762{
763 if (e.Curr.Y >= e.Next->Curr.Y)
764 {
765 e.Bot = e.Curr;
766 e.Top = e.Next->Curr;
767 } else
768 {
769 e.Top = e.Curr;
770 e.Bot = e.Next->Curr;
771 }
772 SetDx(e);
773 e.PolyTyp = Pt;
774}
775//------------------------------------------------------------------------------
776
777TEdge* RemoveEdge(TEdge* e)
778{
779 //removes e from double_linked_list (but without removing from memory)
780 e->Prev->Next = e->Next;
781 e->Next->Prev = e->Prev;
782 TEdge* result = e->Next;
783 e->Prev = 0; //flag as removed (see ClipperBase.Clear)
784 return result;
785}
786//------------------------------------------------------------------------------
787
788inline void ReverseHorizontal(TEdge &e)
789{
790 //swap horizontal edges' Top and Bottom x's so they follow the natural
791 //progression of the bounds - ie so their xbots will align with the
792 //adjoining lower edge. [Helpful in the ProcessHorizontal() method.]
793 std::swap(e.Top.X, e.Bot.X);
794#ifdef use_xyz
795 std::swap(e.Top.Z, e.Bot.Z);
796#endif
797}
798//------------------------------------------------------------------------------
799
800void SwapPoints(IntPoint &pt1, IntPoint &pt2)
801{
802 IntPoint tmp = pt1;
803 pt1 = pt2;
804 pt2 = tmp;
805}
806//------------------------------------------------------------------------------
807
808bool GetOverlapSegment(IntPoint pt1a, IntPoint pt1b, IntPoint pt2a,
809 IntPoint pt2b, IntPoint &pt1, IntPoint &pt2)
810{
811 //precondition: segments are Collinear.
812 if (Abs(pt1a.X - pt1b.X) > Abs(pt1a.Y - pt1b.Y))
813 {
814 if (pt1a.X > pt1b.X) SwapPoints(pt1a, pt1b);
815 if (pt2a.X > pt2b.X) SwapPoints(pt2a, pt2b);
816 if (pt1a.X > pt2a.X) pt1 = pt1a; else pt1 = pt2a;
817 if (pt1b.X < pt2b.X) pt2 = pt1b; else pt2 = pt2b;
818 return pt1.X < pt2.X;
819 } else
820 {
821 if (pt1a.Y < pt1b.Y) SwapPoints(pt1a, pt1b);
822 if (pt2a.Y < pt2b.Y) SwapPoints(pt2a, pt2b);
823 if (pt1a.Y < pt2a.Y) pt1 = pt1a; else pt1 = pt2a;
824 if (pt1b.Y > pt2b.Y) pt2 = pt1b; else pt2 = pt2b;
825 return pt1.Y > pt2.Y;
826 }
827}
828//------------------------------------------------------------------------------
829
830bool FirstIsBottomPt(const OutPt* btmPt1, const OutPt* btmPt2)
831{
832 OutPt *p = btmPt1->Prev;
833 while ((p->Pt == btmPt1->Pt) && (p != btmPt1)) p = p->Prev;
834 double dx1p = std::fabs(GetDx(btmPt1->Pt, p->Pt));
835 p = btmPt1->Next;
836 while ((p->Pt == btmPt1->Pt) && (p != btmPt1)) p = p->Next;
837 double dx1n = std::fabs(GetDx(btmPt1->Pt, p->Pt));
838
839 p = btmPt2->Prev;
840 while ((p->Pt == btmPt2->Pt) && (p != btmPt2)) p = p->Prev;
841 double dx2p = std::fabs(GetDx(btmPt2->Pt, p->Pt));
842 p = btmPt2->Next;
843 while ((p->Pt == btmPt2->Pt) && (p != btmPt2)) p = p->Next;
844 double dx2n = std::fabs(GetDx(btmPt2->Pt, p->Pt));
845
846 if (std::max(dx1p, dx1n) == std::max(dx2p, dx2n) &&
847 std::min(dx1p, dx1n) == std::min(dx2p, dx2n))
848 return Area(btmPt1) > 0; //if otherwise identical use orientation
849 else
850 return (dx1p >= dx2p && dx1p >= dx2n) || (dx1n >= dx2p && dx1n >= dx2n);
851}
852//------------------------------------------------------------------------------
853
854OutPt* GetBottomPt(OutPt *pp)
855{
856 OutPt* dups = 0;
857 OutPt* p = pp->Next;
858 while (p != pp)
859 {
860 if (p->Pt.Y > pp->Pt.Y)
861 {
862 pp = p;
863 dups = 0;
864 }
865 else if (p->Pt.Y == pp->Pt.Y && p->Pt.X <= pp->Pt.X)
866 {
867 if (p->Pt.X < pp->Pt.X)
868 {
869 dups = 0;
870 pp = p;
871 } else
872 {
873 if (p->Next != pp && p->Prev != pp) dups = p;
874 }
875 }
876 p = p->Next;
877 }
878 if (dups)
879 {
880 //there appears to be at least 2 vertices at BottomPt so ...
881 while (dups != p)
882 {
883 if (!FirstIsBottomPt(p, dups)) pp = dups;
884 dups = dups->Next;
885 while (dups->Pt != pp->Pt) dups = dups->Next;
886 }
887 }
888 return pp;
889}
890//------------------------------------------------------------------------------
891
892bool Pt2IsBetweenPt1AndPt3(const IntPoint pt1,
893 const IntPoint pt2, const IntPoint pt3)
894{
895 if ((pt1 == pt3) || (pt1 == pt2) || (pt3 == pt2))
896 return false;
897 else if (pt1.X != pt3.X)
898 return (pt2.X > pt1.X) == (pt2.X < pt3.X);
899 else
900 return (pt2.Y > pt1.Y) == (pt2.Y < pt3.Y);
901}
902//------------------------------------------------------------------------------
903
904bool HorzSegmentsOverlap(cInt seg1a, cInt seg1b, cInt seg2a, cInt seg2b)
905{
906 if (seg1a > seg1b) std::swap(seg1a, seg1b);
907 if (seg2a > seg2b) std::swap(seg2a, seg2b);
908 return (seg1a < seg2b) && (seg2a < seg1b);
909}
910
911//------------------------------------------------------------------------------
912// ClipperBase class methods ...
913//------------------------------------------------------------------------------
914
915ClipperBase::ClipperBase() //constructor
916{
917 m_CurrentLM = m_MinimaList.begin(); //begin() == end() here
918 m_UseFullRange = false;
919}
920//------------------------------------------------------------------------------
921
922ClipperBase::~ClipperBase() //destructor
923{
924 Clear();
925}
926//------------------------------------------------------------------------------
927
928void RangeTest(const IntPoint& Pt, bool& useFullRange)
929{
930 if (useFullRange)
931 {
932 if (Pt.X > hiRange || Pt.Y > hiRange || -Pt.X > hiRange || -Pt.Y > hiRange)
933 CLIPPER_THROW(clipperException("Coordinate outside allowed range"));
934 }
935 else if (Pt.X > loRange|| Pt.Y > loRange || -Pt.X > loRange || -Pt.Y > loRange)
936 {
937 useFullRange = true;
938 RangeTest(Pt, useFullRange);
939 }
940}
941//------------------------------------------------------------------------------
942
943TEdge* FindNextLocMin(TEdge* E)
944{
945 for (;;)
946 {
947 while (E->Bot != E->Prev->Bot || E->Curr == E->Top) E = E->Next;
948 if (!IsHorizontal(*E) && !IsHorizontal(*E->Prev)) break;
949 while (IsHorizontal(*E->Prev)) E = E->Prev;
950 TEdge* E2 = E;
951 while (IsHorizontal(*E)) E = E->Next;
952 if (E->Top.Y == E->Prev->Bot.Y) continue; //ie just an intermediate horz.
953 if (E2->Prev->Bot.X < E->Bot.X) E = E2;
954 break;
955 }
956 return E;
957}
958//------------------------------------------------------------------------------
959
960TEdge* ClipperBase::ProcessBound(TEdge* E, bool NextIsForward)
961{
962 TEdge *Result = E;
963 TEdge *Horz = 0;
964
965 if (E->OutIdx == Skip)
966 {
967 //if edges still remain in the current bound beyond the skip edge then
968 //create another LocMin and call ProcessBound once more
969 if (NextIsForward)
970 {
971 while (E->Top.Y == E->Next->Bot.Y) E = E->Next;
972 //don't include top horizontals when parsing a bound a second time,
973 //they will be contained in the opposite bound ...
974 while (E != Result && IsHorizontal(*E)) E = E->Prev;
975 }
976 else
977 {
978 while (E->Top.Y == E->Prev->Bot.Y) E = E->Prev;
979 while (E != Result && IsHorizontal(*E)) E = E->Next;
980 }
981
982 if (E == Result)
983 {
984 if (NextIsForward) Result = E->Next;
985 else Result = E->Prev;
986 }
987 else
988 {
989 //there are more edges in the bound beyond result starting with E
990 if (NextIsForward)
991 E = Result->Next;
992 else
993 E = Result->Prev;
994 MinimaList::value_type locMin;
995 locMin.Y = E->Bot.Y;
996 locMin.LeftBound = 0;
997 locMin.RightBound = E;
998 E->WindDelta = 0;
999 Result = ProcessBound(E, NextIsForward);
1000 m_MinimaList.push_back(locMin);
1001 }
1002 return Result;
1003 }
1004
1005 TEdge *EStart;
1006
1007 if (IsHorizontal(*E))
1008 {
1009 //We need to be careful with open paths because this may not be a
1010 //true local minima (ie E may be following a skip edge).
1011 //Also, consecutive horz. edges may start heading left before going right.
1012 if (NextIsForward)
1013 EStart = E->Prev;
1014 else
1015 EStart = E->Next;
1016 if (IsHorizontal(*EStart)) //ie an adjoining horizontal skip edge
1017 {
1018 if (EStart->Bot.X != E->Bot.X && EStart->Top.X != E->Bot.X)
1019 ReverseHorizontal(*E);
1020 }
1021 else if (EStart->Bot.X != E->Bot.X)
1022 ReverseHorizontal(*E);
1023 }
1024
1025 EStart = E;
1026 if (NextIsForward)
1027 {
1028 while (Result->Top.Y == Result->Next->Bot.Y && Result->Next->OutIdx != Skip)
1029 Result = Result->Next;
1030 if (IsHorizontal(*Result) && Result->Next->OutIdx != Skip)
1031 {
1032 //nb: at the top of a bound, horizontals are added to the bound
1033 //only when the preceding edge attaches to the horizontal's left vertex
1034 //unless a Skip edge is encountered when that becomes the top divide
1035 Horz = Result;
1036 while (IsHorizontal(*Horz->Prev)) Horz = Horz->Prev;
1037 if (Horz->Prev->Top.X > Result->Next->Top.X) Result = Horz->Prev;
1038 }
1039 while (E != Result)
1040 {
1041 E->NextInLML = E->Next;
1042 if (IsHorizontal(*E) && E != EStart &&
1043 E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E);
1044 E = E->Next;
1045 }
1046 if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Prev->Top.X)
1047 ReverseHorizontal(*E);
1048 Result = Result->Next; //move to the edge just beyond current bound
1049 } else
1050 {
1051 while (Result->Top.Y == Result->Prev->Bot.Y && Result->Prev->OutIdx != Skip)
1052 Result = Result->Prev;
1053 if (IsHorizontal(*Result) && Result->Prev->OutIdx != Skip)
1054 {
1055 Horz = Result;
1056 while (IsHorizontal(*Horz->Next)) Horz = Horz->Next;
1057 if (Horz->Next->Top.X == Result->Prev->Top.X ||
1058 Horz->Next->Top.X > Result->Prev->Top.X) Result = Horz->Next;
1059 }
1060
1061 while (E != Result)
1062 {
1063 E->NextInLML = E->Prev;
1064 if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Next->Top.X)
1065 ReverseHorizontal(*E);
1066 E = E->Prev;
1067 }
1068 if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Next->Top.X)
1069 ReverseHorizontal(*E);
1070 Result = Result->Prev; //move to the edge just beyond current bound
1071 }
1072
1073 return Result;
1074}
1075//------------------------------------------------------------------------------
1076
1077bool ClipperBase::AddPath(const Path &pg, PolyType PolyTyp, bool Closed)
1078{
1079#ifdef use_lines
1080 if (!Closed && PolyTyp == ptClip)
1081 CLIPPER_THROW(clipperException("AddPath: Open paths must be subject."));
1082#else
1083 if (!Closed)
1084 CLIPPER_THROW(clipperException("AddPath: Open paths have been disabled."));
1085#endif
1086
1087 int highI = (int)pg.size() -1;
1088 if (Closed) while (highI > 0 && (pg[highI] == pg[0])) --highI;
1089 while (highI > 0 && (pg[highI] == pg[highI -1])) --highI;
1090 if ((Closed && highI < 2) || (!Closed && highI < 1)) return false;
1091
1092 //create a new edge array ...
1093 TEdge *edges = new TEdge [highI +1];
1094
1095 bool IsFlat = true;
1096 //1. Basic (first) edge initialization ...
1097 CLIPPER_TRY
1098 {
1099 edges[1].Curr = pg[1];
1100 RangeTest(pg[0], m_UseFullRange);
1101 RangeTest(pg[highI], m_UseFullRange);
1102 InitEdge(&edges[0], &edges[1], &edges[highI], pg[0]);
1103 InitEdge(&edges[highI], &edges[0], &edges[highI-1], pg[highI]);
1104 for (int i = highI - 1; i >= 1; --i)
1105 {
1106 RangeTest(pg[i], m_UseFullRange);
1107 InitEdge(&edges[i], &edges[i+1], &edges[i-1], pg[i]);
1108 }
1109 }
1110 CLIPPER_CATCH(...)
1111 {
1112 delete [] edges;
1113 CLIPPER_THROW(); //range test fails
1114 }
1115 TEdge *eStart = &edges[0];
1116
1117 //2. Remove duplicate vertices, and (when closed) collinear edges ...
1118 TEdge *E = eStart, *eLoopStop = eStart;
1119 for (;;)
1120 {
1121 //nb: allows matching start and end points when not Closed ...
1122 if (E->Curr == E->Next->Curr && (Closed || E->Next != eStart))
1123 {
1124 if (E == E->Next) break;
1125 if (E == eStart) eStart = E->Next;
1126 E = RemoveEdge(E);
1127 eLoopStop = E;
1128 continue;
1129 }
1130 if (E->Prev == E->Next)
1131 break; //only two vertices
1132 else if (Closed &&
1133 SlopesEqual(E->Prev->Curr, E->Curr, E->Next->Curr, m_UseFullRange) &&
1134 (!m_PreserveCollinear ||
1135 !Pt2IsBetweenPt1AndPt3(E->Prev->Curr, E->Curr, E->Next->Curr)))
1136 {
1137 //Collinear edges are allowed for open paths but in closed paths
1138 //the default is to merge adjacent collinear edges into a single edge.
1139 //However, if the PreserveCollinear property is enabled, only overlapping
1140 //collinear edges (ie spikes) will be removed from closed paths.
1141 if (E == eStart) eStart = E->Next;
1142 E = RemoveEdge(E);
1143 E = E->Prev;
1144 eLoopStop = E;
1145 continue;
1146 }
1147 E = E->Next;
1148 if ((E == eLoopStop) || (!Closed && E->Next == eStart)) break;
1149 }
1150
1151 if ((!Closed && (E == E->Next)) || (Closed && (E->Prev == E->Next)))
1152 {
1153 delete [] edges;
1154 return false;
1155 }
1156
1157 if (!Closed)
1158 {
1159 m_HasOpenPaths = true;
1160 eStart->Prev->OutIdx = Skip;
1161 }
1162
1163 //3. Do second stage of edge initialization ...
1164 E = eStart;
1165 do
1166 {
1167 InitEdge2(*E, PolyTyp);
1168 E = E->Next;
1169 if (IsFlat && E->Curr.Y != eStart->Curr.Y) IsFlat = false;
1170 }
1171 while (E != eStart);
1172
1173 //4. Finally, add edge bounds to LocalMinima list ...
1174
1175 //Totally flat paths must be handled differently when adding them
1176 //to LocalMinima list to avoid endless loops etc ...
1177 if (IsFlat)
1178 {
1179 if (Closed)
1180 {
1181 delete [] edges;
1182 return false;
1183 }
1184 E->Prev->OutIdx = Skip;
1185 MinimaList::value_type locMin;
1186 locMin.Y = E->Bot.Y;
1187 locMin.LeftBound = 0;
1188 locMin.RightBound = E;
1189 locMin.RightBound->Side = esRight;
1190 locMin.RightBound->WindDelta = 0;
1191 for (;;)
1192 {
1193 if (E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E);
1194 if (E->Next->OutIdx == Skip) break;
1195 E->NextInLML = E->Next;
1196 E = E->Next;
1197 }
1198 m_MinimaList.push_back(locMin);
1199 m_edges.push_back(edges);
1200 return true;
1201 }
1202
1203 m_edges.push_back(edges);
1204 bool leftBoundIsForward;
1205 TEdge* EMin = 0;
1206
1207 //workaround to avoid an endless loop in the while loop below when
1208 //open paths have matching start and end points ...
1209 if (E->Prev->Bot == E->Prev->Top) E = E->Next;
1210
1211 for (;;)
1212 {
1213 E = FindNextLocMin(E);
1214 if (E == EMin) break;
1215 else if (!EMin) EMin = E;
1216
1217 //E and E.Prev now share a local minima (left aligned if horizontal).
1218 //Compare their slopes to find which starts which bound ...
1219 MinimaList::value_type locMin;
1220 locMin.Y = E->Bot.Y;
1221 if (E->Dx < E->Prev->Dx)
1222 {
1223 locMin.LeftBound = E->Prev;
1224 locMin.RightBound = E;
1225 leftBoundIsForward = false; //Q.nextInLML = Q.prev
1226 } else
1227 {
1228 locMin.LeftBound = E;
1229 locMin.RightBound = E->Prev;
1230 leftBoundIsForward = true; //Q.nextInLML = Q.next
1231 }
1232
1233 if (!Closed) locMin.LeftBound->WindDelta = 0;
1234 else if (locMin.LeftBound->Next == locMin.RightBound)
1235 locMin.LeftBound->WindDelta = -1;
1236 else locMin.LeftBound->WindDelta = 1;
1237 locMin.RightBound->WindDelta = -locMin.LeftBound->WindDelta;
1238
1239 E = ProcessBound(locMin.LeftBound, leftBoundIsForward);
1240 if (E->OutIdx == Skip) E = ProcessBound(E, leftBoundIsForward);
1241
1242 TEdge* E2 = ProcessBound(locMin.RightBound, !leftBoundIsForward);
1243 if (E2->OutIdx == Skip) E2 = ProcessBound(E2, !leftBoundIsForward);
1244
1245 if (locMin.LeftBound->OutIdx == Skip)
1246 locMin.LeftBound = 0;
1247 else if (locMin.RightBound->OutIdx == Skip)
1248 locMin.RightBound = 0;
1249 m_MinimaList.push_back(locMin);
1250 if (!leftBoundIsForward) E = E2;
1251 }
1252 return true;
1253}
1254//------------------------------------------------------------------------------
1255
1256bool ClipperBase::AddPaths(const Paths &ppg, PolyType PolyTyp, bool Closed)
1257{
1258 bool result = false;
1259 for (Paths::size_type i = 0; i < ppg.size(); ++i)
1260 if (AddPath(ppg[i], PolyTyp, Closed)) result = true;
1261 return result;
1262}
1263//------------------------------------------------------------------------------
1264
1265void ClipperBase::Clear()
1266{
1267 DisposeLocalMinimaList();
1268 for (EdgeList::size_type i = 0; i < m_edges.size(); ++i)
1269 {
1270 TEdge* edges = m_edges[i];
1271 delete [] edges;
1272 }
1273 m_edges.clear();
1274 m_UseFullRange = false;
1275 m_HasOpenPaths = false;
1276}
1277//------------------------------------------------------------------------------
1278
1279void ClipperBase::Reset()
1280{
1281 m_CurrentLM = m_MinimaList.begin();
1282 if (m_CurrentLM == m_MinimaList.end()) return; //ie nothing to process
1283 std::sort(m_MinimaList.begin(), m_MinimaList.end(), LocMinSorter());
1284
1285 m_Scanbeam = ScanbeamList(); //clears/resets priority_queue
1286 //reset all edges ...
1287 for (MinimaList::iterator lm = m_MinimaList.begin(); lm != m_MinimaList.end(); ++lm)
1288 {
1289 InsertScanbeam(lm->Y);
1290 TEdge* e = lm->LeftBound;
1291 if (e)
1292 {
1293 e->Curr = e->Bot;
1294 e->Side = esLeft;
1295 e->OutIdx = Unassigned;
1296 }
1297
1298 e = lm->RightBound;
1299 if (e)
1300 {
1301 e->Curr = e->Bot;
1302 e->Side = esRight;
1303 e->OutIdx = Unassigned;
1304 }
1305 }
1306 m_ActiveEdges = 0;
1307 m_CurrentLM = m_MinimaList.begin();
1308}
1309//------------------------------------------------------------------------------
1310
1311void ClipperBase::DisposeLocalMinimaList()
1312{
1313 m_MinimaList.clear();
1314 m_CurrentLM = m_MinimaList.begin();
1315}
1316//------------------------------------------------------------------------------
1317
1318bool ClipperBase::PopLocalMinima(cInt Y, const LocalMinimum *&locMin)
1319{
1320 if (m_CurrentLM == m_MinimaList.end() || (*m_CurrentLM).Y != Y) return false;
1321 locMin = &(*m_CurrentLM);
1322 ++m_CurrentLM;
1323 return true;
1324}
1325//------------------------------------------------------------------------------
1326
1327IntRect ClipperBase::GetBounds()
1328{
1329 IntRect result;
1330 MinimaList::iterator lm = m_MinimaList.begin();
1331 if (lm == m_MinimaList.end())
1332 {
1333 result.left = result.top = result.right = result.bottom = 0;
1334 return result;
1335 }
1336 result.left = lm->LeftBound->Bot.X;
1337 result.top = lm->LeftBound->Bot.Y;
1338 result.right = lm->LeftBound->Bot.X;
1339 result.bottom = lm->LeftBound->Bot.Y;
1340 while (lm != m_MinimaList.end())
1341 {
1342 //todo - needs fixing for open paths
1343 result.bottom = std::max(result.bottom, lm->LeftBound->Bot.Y);
1344 TEdge* e = lm->LeftBound;
1345 for (;;) {
1346 TEdge* bottomE = e;
1347 while (e->NextInLML)
1348 {
1349 if (e->Bot.X < result.left) result.left = e->Bot.X;
1350 if (e->Bot.X > result.right) result.right = e->Bot.X;
1351 e = e->NextInLML;
1352 }
1353 result.left = std::min(result.left, e->Bot.X);
1354 result.right = std::max(result.right, e->Bot.X);
1355 result.left = std::min(result.left, e->Top.X);
1356 result.right = std::max(result.right, e->Top.X);
1357 result.top = std::min(result.top, e->Top.Y);
1358 if (bottomE == lm->LeftBound) e = lm->RightBound;
1359 else break;
1360 }
1361 ++lm;
1362 }
1363 return result;
1364}
1365//------------------------------------------------------------------------------
1366
1367void ClipperBase::InsertScanbeam(const cInt Y)
1368{
1369 m_Scanbeam.push(Y);
1370}
1371//------------------------------------------------------------------------------
1372
1373bool ClipperBase::PopScanbeam(cInt &Y)
1374{
1375 if (m_Scanbeam.empty()) return false;
1376 Y = m_Scanbeam.top();
1377 m_Scanbeam.pop();
1378 while (!m_Scanbeam.empty() && Y == m_Scanbeam.top()) { m_Scanbeam.pop(); } // Pop duplicates.
1379 return true;
1380}
1381//------------------------------------------------------------------------------
1382
1383void ClipperBase::DisposeAllOutRecs(){
1384 for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
1385 DisposeOutRec(i);
1386 m_PolyOuts.clear();
1387}
1388//------------------------------------------------------------------------------
1389
1390void ClipperBase::DisposeOutRec(PolyOutList::size_type index)
1391{
1392 OutRec *outRec = m_PolyOuts[index];
1393 if (outRec->Pts) DisposeOutPts(outRec->Pts);
1394 delete outRec;
1395 m_PolyOuts[index] = 0;
1396}
1397//------------------------------------------------------------------------------
1398
1399void ClipperBase::DeleteFromAEL(TEdge *e)
1400{
1401 TEdge* AelPrev = e->PrevInAEL;
1402 TEdge* AelNext = e->NextInAEL;
1403 if (!AelPrev && !AelNext && (e != m_ActiveEdges)) return; //already deleted
1404 if (AelPrev) AelPrev->NextInAEL = AelNext;
1405 else m_ActiveEdges = AelNext;
1406 if (AelNext) AelNext->PrevInAEL = AelPrev;
1407 e->NextInAEL = 0;
1408 e->PrevInAEL = 0;
1409}
1410//------------------------------------------------------------------------------
1411
1412OutRec* ClipperBase::CreateOutRec()
1413{
1414 OutRec* result = new OutRec;
1415 result->IsHole = false;
1416 result->IsOpen = false;
1417 result->FirstLeft = 0;
1418 result->Pts = 0;
1419 result->BottomPt = 0;
1420 result->PolyNd = 0;
1421 m_PolyOuts.push_back(result);
1422 result->Idx = (int)m_PolyOuts.size() - 1;
1423 return result;
1424}
1425//------------------------------------------------------------------------------
1426
1427void ClipperBase::SwapPositionsInAEL(TEdge *Edge1, TEdge *Edge2)
1428{
1429 //check that one or other edge hasn't already been removed from AEL ...
1430 if (Edge1->NextInAEL == Edge1->PrevInAEL ||
1431 Edge2->NextInAEL == Edge2->PrevInAEL) return;
1432
1433 if (Edge1->NextInAEL == Edge2)
1434 {
1435 TEdge* Next = Edge2->NextInAEL;
1436 if (Next) Next->PrevInAEL = Edge1;
1437 TEdge* Prev = Edge1->PrevInAEL;
1438 if (Prev) Prev->NextInAEL = Edge2;
1439 Edge2->PrevInAEL = Prev;
1440 Edge2->NextInAEL = Edge1;
1441 Edge1->PrevInAEL = Edge2;
1442 Edge1->NextInAEL = Next;
1443 }
1444 else if (Edge2->NextInAEL == Edge1)
1445 {
1446 TEdge* Next = Edge1->NextInAEL;
1447 if (Next) Next->PrevInAEL = Edge2;
1448 TEdge* Prev = Edge2->PrevInAEL;
1449 if (Prev) Prev->NextInAEL = Edge1;
1450 Edge1->PrevInAEL = Prev;
1451 Edge1->NextInAEL = Edge2;
1452 Edge2->PrevInAEL = Edge1;
1453 Edge2->NextInAEL = Next;
1454 }
1455 else
1456 {
1457 TEdge* Next = Edge1->NextInAEL;
1458 TEdge* Prev = Edge1->PrevInAEL;
1459 Edge1->NextInAEL = Edge2->NextInAEL;
1460 if (Edge1->NextInAEL) Edge1->NextInAEL->PrevInAEL = Edge1;
1461 Edge1->PrevInAEL = Edge2->PrevInAEL;
1462 if (Edge1->PrevInAEL) Edge1->PrevInAEL->NextInAEL = Edge1;
1463 Edge2->NextInAEL = Next;
1464 if (Edge2->NextInAEL) Edge2->NextInAEL->PrevInAEL = Edge2;
1465 Edge2->PrevInAEL = Prev;
1466 if (Edge2->PrevInAEL) Edge2->PrevInAEL->NextInAEL = Edge2;
1467 }
1468
1469 if (!Edge1->PrevInAEL) m_ActiveEdges = Edge1;
1470 else if (!Edge2->PrevInAEL) m_ActiveEdges = Edge2;
1471}
1472//------------------------------------------------------------------------------
1473
1474void ClipperBase::UpdateEdgeIntoAEL(TEdge *&e)
1475{
1476 if (!e->NextInLML)
1477 CLIPPER_THROW(clipperException("UpdateEdgeIntoAEL: invalid call"));
1478
1479 e->NextInLML->OutIdx = e->OutIdx;
1480 TEdge* AelPrev = e->PrevInAEL;
1481 TEdge* AelNext = e->NextInAEL;
1482 if (AelPrev) AelPrev->NextInAEL = e->NextInLML;
1483 else m_ActiveEdges = e->NextInLML;
1484 if (AelNext) AelNext->PrevInAEL = e->NextInLML;
1485 e->NextInLML->Side = e->Side;
1486 e->NextInLML->WindDelta = e->WindDelta;
1487 e->NextInLML->WindCnt = e->WindCnt;
1488 e->NextInLML->WindCnt2 = e->WindCnt2;
1489 e = e->NextInLML;
1490 e->Curr = e->Bot;
1491 e->PrevInAEL = AelPrev;
1492 e->NextInAEL = AelNext;
1493 if (!IsHorizontal(*e)) InsertScanbeam(e->Top.Y);
1494}
1495//------------------------------------------------------------------------------
1496
1497bool ClipperBase::LocalMinimaPending()
1498{
1499 return (m_CurrentLM != m_MinimaList.end());
1500}
1501
1502//------------------------------------------------------------------------------
1503// TClipper methods ...
1504//------------------------------------------------------------------------------
1505
1506Clipper::Clipper(int initOptions) : ClipperBase() //constructor
1507{
1508 m_ExecuteLocked = false;
1509 m_UseFullRange = false;
1510 m_ReverseOutput = ((initOptions & ioReverseSolution) != 0);
1511 m_StrictSimple = ((initOptions & ioStrictlySimple) != 0);
1512 m_PreserveCollinear = ((initOptions & ioPreserveCollinear) != 0);
1513 m_HasOpenPaths = false;
1514#ifdef use_xyz
1515 m_ZFill = 0;
1516#endif
1517}
1518//------------------------------------------------------------------------------
1519
1520#ifdef use_xyz
1521void Clipper::ZFillFunction(ZFillCallback zFillFunc)
1522{
1523 m_ZFill = zFillFunc;
1524}
1525//------------------------------------------------------------------------------
1526#endif
1527
1528bool Clipper::Execute(ClipType clipType, Paths &solution, PolyFillType fillType)
1529{
1530 return Execute(clipType, solution, fillType, fillType);
1531}
1532//------------------------------------------------------------------------------
1533
1534bool Clipper::Execute(ClipType clipType, PolyTree &polytree, PolyFillType fillType)
1535{
1536 return Execute(clipType, polytree, fillType, fillType);
1537}
1538//------------------------------------------------------------------------------
1539
1540bool Clipper::Execute(ClipType clipType, Paths &solution,
1541 PolyFillType subjFillType, PolyFillType clipFillType)
1542{
1543 if( m_ExecuteLocked ) return false;
1544 if (m_HasOpenPaths)
1545 CLIPPER_THROW(clipperException("Error: PolyTree struct is needed for open path clipping."));
1546 m_ExecuteLocked = true;
1547 solution.resize(0);
1548 m_SubjFillType = subjFillType;
1549 m_ClipFillType = clipFillType;
1550 m_ClipType = clipType;
1551 m_UsingPolyTree = false;
1552 bool succeeded = ExecuteInternal();
1553 if (succeeded) BuildResult(solution);
1554 DisposeAllOutRecs();
1555 m_ExecuteLocked = false;
1556 return succeeded;
1557}
1558//------------------------------------------------------------------------------
1559
1560bool Clipper::Execute(ClipType clipType, PolyTree& polytree,
1561 PolyFillType subjFillType, PolyFillType clipFillType)
1562{
1563 if( m_ExecuteLocked ) return false;
1564 m_ExecuteLocked = true;
1565 m_SubjFillType = subjFillType;
1566 m_ClipFillType = clipFillType;
1567 m_ClipType = clipType;
1568 m_UsingPolyTree = true;
1569 bool succeeded = ExecuteInternal();
1570 if (succeeded) BuildResult2(polytree);
1571 DisposeAllOutRecs();
1572 m_ExecuteLocked = false;
1573 return succeeded;
1574}
1575//------------------------------------------------------------------------------
1576
1577void Clipper::FixHoleLinkage(OutRec &outrec)
1578{
1579 //skip OutRecs that (a) contain outermost polygons or
1580 //(b) already have the correct owner/child linkage ...
1581 if (!outrec.FirstLeft ||
1582 (outrec.IsHole != outrec.FirstLeft->IsHole &&
1583 outrec.FirstLeft->Pts)) return;
1584
1585 OutRec* orfl = outrec.FirstLeft;
1586 while (orfl && ((orfl->IsHole == outrec.IsHole) || !orfl->Pts))
1587 orfl = orfl->FirstLeft;
1588 outrec.FirstLeft = orfl;
1589}
1590//------------------------------------------------------------------------------
1591
1592bool Clipper::ExecuteInternal()
1593{
1594 bool succeeded = true;
1595 CLIPPER_TRY {
1596 Reset();
1597 m_Maxima = MaximaList();
1598 m_SortedEdges = 0;
1599
1600 succeeded = true;
1601 cInt botY, topY;
1602 if (!PopScanbeam(botY)) return false;
1603 InsertLocalMinimaIntoAEL(botY);
1604 while (PopScanbeam(topY) || LocalMinimaPending())
1605 {
1606 ProcessHorizontals();
1607 ClearGhostJoins();
1608 if (!ProcessIntersections(topY))
1609 {
1610 succeeded = false;
1611 break;
1612 }
1613 ProcessEdgesAtTopOfScanbeam(topY);
1614 botY = topY;
1615 InsertLocalMinimaIntoAEL(botY);
1616 }
1617 }
1618 CLIPPER_CATCH(...)
1619 {
1620 succeeded = false;
1621 }
1622
1623 if (succeeded)
1624 {
1625 //fix orientations ...
1626 for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
1627 {
1628 OutRec *outRec = m_PolyOuts[i];
1629 if (!outRec->Pts || outRec->IsOpen) continue;
1630 if ((outRec->IsHole ^ m_ReverseOutput) == (Area(*outRec) > 0))
1631 ReversePolyPtLinks(outRec->Pts);
1632 }
1633
1634 if (!m_Joins.empty()) JoinCommonEdges();
1635
1636 //unfortunately FixupOutPolygon() must be done after JoinCommonEdges()
1637 for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
1638 {
1639 OutRec *outRec = m_PolyOuts[i];
1640 if (!outRec->Pts) continue;
1641 if (outRec->IsOpen)
1642 FixupOutPolyline(*outRec);
1643 else
1644 FixupOutPolygon(*outRec);
1645 }
1646
1647 if (m_StrictSimple) DoSimplePolygons();
1648 }
1649
1650 ClearJoins();
1651 ClearGhostJoins();
1652 return succeeded;
1653}
1654//------------------------------------------------------------------------------
1655
1656void Clipper::SetWindingCount(TEdge &edge)
1657{
1658 TEdge *e = edge.PrevInAEL;
1659 //find the edge of the same polytype that immediately preceeds 'edge' in AEL
1660 while (e && ((e->PolyTyp != edge.PolyTyp) || (e->WindDelta == 0))) e = e->PrevInAEL;
1661 if (!e)
1662 {
1663 if (edge.WindDelta == 0)
1664 {
1665 PolyFillType pft = (edge.PolyTyp == ptSubject ? m_SubjFillType : m_ClipFillType);
1666 edge.WindCnt = (pft == pftNegative ? -1 : 1);
1667 }
1668 else
1669 edge.WindCnt = edge.WindDelta;
1670 edge.WindCnt2 = 0;
1671 e = m_ActiveEdges; //ie get ready to calc WindCnt2
1672 }
1673 else if (edge.WindDelta == 0 && m_ClipType != ctUnion)
1674 {
1675 edge.WindCnt = 1;
1676 edge.WindCnt2 = e->WindCnt2;
1677 e = e->NextInAEL; //ie get ready to calc WindCnt2
1678 }
1679 else if (IsEvenOddFillType(edge))
1680 {
1681 //EvenOdd filling ...
1682 if (edge.WindDelta == 0)
1683 {
1684 //are we inside a subj polygon ...
1685 bool Inside = true;
1686 TEdge *e2 = e->PrevInAEL;
1687 while (e2)
1688 {
1689 if (e2->PolyTyp == e->PolyTyp && e2->WindDelta != 0)
1690 Inside = !Inside;
1691 e2 = e2->PrevInAEL;
1692 }
1693 edge.WindCnt = (Inside ? 0 : 1);
1694 }
1695 else
1696 {
1697 edge.WindCnt = edge.WindDelta;
1698 }
1699 edge.WindCnt2 = e->WindCnt2;
1700 e = e->NextInAEL; //ie get ready to calc WindCnt2
1701 }
1702 else
1703 {
1704 //nonZero, Positive or Negative filling ...
1705 if (e->WindCnt * e->WindDelta < 0)
1706 {
1707 //prev edge is 'decreasing' WindCount (WC) toward zero
1708 //so we're outside the previous polygon ...
1709 if (Abs(e->WindCnt) > 1)
1710 {
1711 //outside prev poly but still inside another.
1712 //when reversing direction of prev poly use the same WC
1713 if (e->WindDelta * edge.WindDelta < 0) edge.WindCnt = e->WindCnt;
1714 //otherwise continue to 'decrease' WC ...
1715 else edge.WindCnt = e->WindCnt + edge.WindDelta;
1716 }
1717 else
1718 //now outside all polys of same polytype so set own WC ...
1719 edge.WindCnt = (edge.WindDelta == 0 ? 1 : edge.WindDelta);
1720 } else
1721 {
1722 //prev edge is 'increasing' WindCount (WC) away from zero
1723 //so we're inside the previous polygon ...
1724 if (edge.WindDelta == 0)
1725 edge.WindCnt = (e->WindCnt < 0 ? e->WindCnt - 1 : e->WindCnt + 1);
1726 //if wind direction is reversing prev then use same WC
1727 else if (e->WindDelta * edge.WindDelta < 0) edge.WindCnt = e->WindCnt;
1728 //otherwise add to WC ...
1729 else edge.WindCnt = e->WindCnt + edge.WindDelta;
1730 }
1731 edge.WindCnt2 = e->WindCnt2;
1732 e = e->NextInAEL; //ie get ready to calc WindCnt2
1733 }
1734
1735 //update WindCnt2 ...
1736 if (IsEvenOddAltFillType(edge))
1737 {
1738 //EvenOdd filling ...
1739 while (e != &edge)
1740 {
1741 if (e->WindDelta != 0)
1742 edge.WindCnt2 = (edge.WindCnt2 == 0 ? 1 : 0);
1743 e = e->NextInAEL;
1744 }
1745 } else
1746 {
1747 //nonZero, Positive or Negative filling ...
1748 while ( e != &edge )
1749 {
1750 edge.WindCnt2 += e->WindDelta;
1751 e = e->NextInAEL;
1752 }
1753 }
1754}
1755//------------------------------------------------------------------------------
1756
1757bool Clipper::IsEvenOddFillType(const TEdge& edge) const
1758{
1759 if (edge.PolyTyp == ptSubject)
1760 return m_SubjFillType == pftEvenOdd; else
1761 return m_ClipFillType == pftEvenOdd;
1762}
1763//------------------------------------------------------------------------------
1764
1765bool Clipper::IsEvenOddAltFillType(const TEdge& edge) const
1766{
1767 if (edge.PolyTyp == ptSubject)
1768 return m_ClipFillType == pftEvenOdd; else
1769 return m_SubjFillType == pftEvenOdd;
1770}
1771//------------------------------------------------------------------------------
1772
1773bool Clipper::IsContributing(const TEdge& edge) const
1774{
1775 PolyFillType pft, pft2;
1776 if (edge.PolyTyp == ptSubject)
1777 {
1778 pft = m_SubjFillType;
1779 pft2 = m_ClipFillType;
1780 } else
1781 {
1782 pft = m_ClipFillType;
1783 pft2 = m_SubjFillType;
1784 }
1785
1786 switch(pft)
1787 {
1788 case pftEvenOdd:
1789 //return false if a subj line has been flagged as inside a subj polygon
1790 if (edge.WindDelta == 0 && edge.WindCnt != 1) return false;
1791 break;
1792 case pftNonZero:
1793 if (Abs(edge.WindCnt) != 1) return false;
1794 break;
1795 case pftPositive:
1796 if (edge.WindCnt != 1) return false;
1797 break;
1798 default: //pftNegative
1799 if (edge.WindCnt != -1) return false;
1800 }
1801
1802 switch(m_ClipType)
1803 {
1804 case ctIntersection:
1805 switch(pft2)
1806 {
1807 case pftEvenOdd:
1808 case pftNonZero:
1809 return (edge.WindCnt2 != 0);
1810 case pftPositive:
1811 return (edge.WindCnt2 > 0);
1812 default:
1813 return (edge.WindCnt2 < 0);
1814 }
1815 break;
1816 case ctUnion:
1817 switch(pft2)
1818 {
1819 case pftEvenOdd:
1820 case pftNonZero:
1821 return (edge.WindCnt2 == 0);
1822 case pftPositive:
1823 return (edge.WindCnt2 <= 0);
1824 default:
1825 return (edge.WindCnt2 >= 0);
1826 }
1827 break;
1828 case ctDifference:
1829 if (edge.PolyTyp == ptSubject)
1830 switch(pft2)
1831 {
1832 case pftEvenOdd:
1833 case pftNonZero:
1834 return (edge.WindCnt2 == 0);
1835 case pftPositive:
1836 return (edge.WindCnt2 <= 0);
1837 default:
1838 return (edge.WindCnt2 >= 0);
1839 }
1840 else
1841 switch(pft2)
1842 {
1843 case pftEvenOdd:
1844 case pftNonZero:
1845 return (edge.WindCnt2 != 0);
1846 case pftPositive:
1847 return (edge.WindCnt2 > 0);
1848 default:
1849 return (edge.WindCnt2 < 0);
1850 }
1851 break;
1852 case ctXor:
1853 if (edge.WindDelta == 0) //XOr always contributing unless open
1854 switch(pft2)
1855 {
1856 case pftEvenOdd:
1857 case pftNonZero:
1858 return (edge.WindCnt2 == 0);
1859 case pftPositive:
1860 return (edge.WindCnt2 <= 0);
1861 default:
1862 return (edge.WindCnt2 >= 0);
1863 }
1864 else
1865 return true;
1866 break;
1867 default:
1868 return true;
1869 }
1870}
1871//------------------------------------------------------------------------------
1872
1873OutPt* Clipper::AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &Pt)
1874{
1875 OutPt* result;
1876 TEdge *e, *prevE;
1877 if (IsHorizontal(*e2) || ( e1->Dx > e2->Dx ))
1878 {
1879 result = AddOutPt(e1, Pt);
1880 e2->OutIdx = e1->OutIdx;
1881 e1->Side = esLeft;
1882 e2->Side = esRight;
1883 e = e1;
1884 if (e->PrevInAEL == e2)
1885 prevE = e2->PrevInAEL;
1886 else
1887 prevE = e->PrevInAEL;
1888 } else
1889 {
1890 result = AddOutPt(e2, Pt);
1891 e1->OutIdx = e2->OutIdx;
1892 e1->Side = esRight;
1893 e2->Side = esLeft;
1894 e = e2;
1895 if (e->PrevInAEL == e1)
1896 prevE = e1->PrevInAEL;
1897 else
1898 prevE = e->PrevInAEL;
1899 }
1900
1901 if (prevE && prevE->OutIdx >= 0 && prevE->Top.Y < Pt.Y && e->Top.Y < Pt.Y)
1902 {
1903 cInt xPrev = TopX(*prevE, Pt.Y);
1904 cInt xE = TopX(*e, Pt.Y);
1905 if (xPrev == xE && (e->WindDelta != 0) && (prevE->WindDelta != 0) &&
1906 SlopesEqual(IntPoint(xPrev, Pt.Y), prevE->Top, IntPoint(xE, Pt.Y), e->Top, m_UseFullRange))
1907 {
1908 OutPt* outPt = AddOutPt(prevE, Pt);
1909 AddJoin(result, outPt, e->Top);
1910 }
1911 }
1912 return result;
1913}
1914//------------------------------------------------------------------------------
1915
1916void Clipper::AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &Pt)
1917{
1918 AddOutPt( e1, Pt );
1919 if (e2->WindDelta == 0) AddOutPt(e2, Pt);
1920 if( e1->OutIdx == e2->OutIdx )
1921 {
1922 e1->OutIdx = Unassigned;
1923 e2->OutIdx = Unassigned;
1924 }
1925 else if (e1->OutIdx < e2->OutIdx)
1926 AppendPolygon(e1, e2);
1927 else
1928 AppendPolygon(e2, e1);
1929}
1930//------------------------------------------------------------------------------
1931
1932void Clipper::AddEdgeToSEL(TEdge *edge)
1933{
1934 //SEL pointers in PEdge are reused to build a list of horizontal edges.
1935 //However, we don't need to worry about order with horizontal edge processing.
1936 if( !m_SortedEdges )
1937 {
1938 m_SortedEdges = edge;
1939 edge->PrevInSEL = 0;
1940 edge->NextInSEL = 0;
1941 }
1942 else
1943 {
1944 edge->NextInSEL = m_SortedEdges;
1945 edge->PrevInSEL = 0;
1946 m_SortedEdges->PrevInSEL = edge;
1947 m_SortedEdges = edge;
1948 }
1949}
1950//------------------------------------------------------------------------------
1951
1952bool Clipper::PopEdgeFromSEL(TEdge *&edge)
1953{
1954 if (!m_SortedEdges) return false;
1955 edge = m_SortedEdges;
1956 DeleteFromSEL(m_SortedEdges);
1957 return true;
1958}
1959//------------------------------------------------------------------------------
1960
1961void Clipper::CopyAELToSEL()
1962{
1963 TEdge* e = m_ActiveEdges;
1964 m_SortedEdges = e;
1965 while ( e )
1966 {
1967 e->PrevInSEL = e->PrevInAEL;
1968 e->NextInSEL = e->NextInAEL;
1969 e = e->NextInAEL;
1970 }
1971}
1972//------------------------------------------------------------------------------
1973
1974void Clipper::AddJoin(OutPt *op1, OutPt *op2, const IntPoint OffPt)
1975{
1976 Join* j = new Join;
1977 j->OutPt1 = op1;
1978 j->OutPt2 = op2;
1979 j->OffPt = OffPt;
1980 m_Joins.push_back(j);
1981}
1982//------------------------------------------------------------------------------
1983
1984void Clipper::ClearJoins()
1985{
1986 for (JoinList::size_type i = 0; i < m_Joins.size(); i++)
1987 delete m_Joins[i];
1988 m_Joins.resize(0);
1989}
1990//------------------------------------------------------------------------------
1991
1992void Clipper::ClearGhostJoins()
1993{
1994 for (JoinList::size_type i = 0; i < m_GhostJoins.size(); i++)
1995 delete m_GhostJoins[i];
1996 m_GhostJoins.resize(0);
1997}
1998//------------------------------------------------------------------------------
1999
2000void Clipper::AddGhostJoin(OutPt *op, const IntPoint OffPt)
2001{
2002 Join* j = new Join;
2003 j->OutPt1 = op;
2004 j->OutPt2 = 0;
2005 j->OffPt = OffPt;
2006 m_GhostJoins.push_back(j);
2007}
2008//------------------------------------------------------------------------------
2009
2010void Clipper::InsertLocalMinimaIntoAEL(const cInt botY)
2011{
2012 const LocalMinimum *lm;
2013 while (PopLocalMinima(botY, lm))
2014 {
2015 TEdge* lb = lm->LeftBound;
2016 TEdge* rb = lm->RightBound;
2017
2018 OutPt *Op1 = 0;
2019 if (!lb)
2020 {
2021 //nb: don't insert LB into either AEL or SEL
2022 InsertEdgeIntoAEL(rb, 0);
2023 SetWindingCount(*rb);
2024 if (IsContributing(*rb))
2025 Op1 = AddOutPt(rb, rb->Bot);
2026 }
2027 else if (!rb)
2028 {
2029 InsertEdgeIntoAEL(lb, 0);
2030 SetWindingCount(*lb);
2031 if (IsContributing(*lb))
2032 Op1 = AddOutPt(lb, lb->Bot);
2033 InsertScanbeam(lb->Top.Y);
2034 }
2035 else
2036 {
2037 InsertEdgeIntoAEL(lb, 0);
2038 InsertEdgeIntoAEL(rb, lb);
2039 SetWindingCount( *lb );
2040 rb->WindCnt = lb->WindCnt;
2041 rb->WindCnt2 = lb->WindCnt2;
2042 if (IsContributing(*lb))
2043 Op1 = AddLocalMinPoly(lb, rb, lb->Bot);
2044 InsertScanbeam(lb->Top.Y);
2045 }
2046
2047 if (rb)
2048 {
2049 if (IsHorizontal(*rb))
2050 {
2051 AddEdgeToSEL(rb);
2052 if (rb->NextInLML)
2053 InsertScanbeam(rb->NextInLML->Top.Y);
2054 }
2055 else InsertScanbeam( rb->Top.Y );
2056 }
2057
2058 if (!lb || !rb) continue;
2059
2060 //if any output polygons share an edge, they'll need joining later ...
2061 if (Op1 && IsHorizontal(*rb) &&
2062 m_GhostJoins.size() > 0 && (rb->WindDelta != 0))
2063 {
2064 for (JoinList::size_type i = 0; i < m_GhostJoins.size(); ++i)
2065 {
2066 Join* jr = m_GhostJoins[i];
2067 //if the horizontal Rb and a 'ghost' horizontal overlap, then convert
2068 //the 'ghost' join to a real join ready for later ...
2069 if (HorzSegmentsOverlap(jr->OutPt1->Pt.X, jr->OffPt.X, rb->Bot.X, rb->Top.X))
2070 AddJoin(jr->OutPt1, Op1, jr->OffPt);
2071 }
2072 }
2073
2074 if (lb->OutIdx >= 0 && lb->PrevInAEL &&
2075 lb->PrevInAEL->Curr.X == lb->Bot.X &&
2076 lb->PrevInAEL->OutIdx >= 0 &&
2077 SlopesEqual(lb->PrevInAEL->Bot, lb->PrevInAEL->Top, lb->Curr, lb->Top, m_UseFullRange) &&
2078 (lb->WindDelta != 0) && (lb->PrevInAEL->WindDelta != 0))
2079 {
2080 OutPt *Op2 = AddOutPt(lb->PrevInAEL, lb->Bot);
2081 AddJoin(Op1, Op2, lb->Top);
2082 }
2083
2084 if(lb->NextInAEL != rb)
2085 {
2086
2087 if (rb->OutIdx >= 0 && rb->PrevInAEL->OutIdx >= 0 &&
2088 SlopesEqual(rb->PrevInAEL->Curr, rb->PrevInAEL->Top, rb->Curr, rb->Top, m_UseFullRange) &&
2089 (rb->WindDelta != 0) && (rb->PrevInAEL->WindDelta != 0))
2090 {
2091 OutPt *Op2 = AddOutPt(rb->PrevInAEL, rb->Bot);
2092 AddJoin(Op1, Op2, rb->Top);
2093 }
2094
2095 TEdge* e = lb->NextInAEL;
2096 if (e)
2097 {
2098 while( e != rb )
2099 {
2100 //nb: For calculating winding counts etc, IntersectEdges() assumes
2101 //that param1 will be to the Right of param2 ABOVE the intersection ...
2102 IntersectEdges(rb , e , lb->Curr); //order important here
2103 e = e->NextInAEL;
2104 }
2105 }
2106 }
2107
2108 }
2109}
2110//------------------------------------------------------------------------------
2111
2112void Clipper::DeleteFromSEL(TEdge *e)
2113{
2114 TEdge* SelPrev = e->PrevInSEL;
2115 TEdge* SelNext = e->NextInSEL;
2116 if( !SelPrev && !SelNext && (e != m_SortedEdges) ) return; //already deleted
2117 if( SelPrev ) SelPrev->NextInSEL = SelNext;
2118 else m_SortedEdges = SelNext;
2119 if( SelNext ) SelNext->PrevInSEL = SelPrev;
2120 e->NextInSEL = 0;
2121 e->PrevInSEL = 0;
2122}
2123//------------------------------------------------------------------------------
2124
2125#ifdef use_xyz
2126void Clipper::SetZ(IntPoint& pt, TEdge& e1, TEdge& e2)
2127{
2128 if (pt.Z != 0 || !m_ZFill) return;
2129 else if (pt == e1.Bot) pt.Z = e1.Bot.Z;
2130 else if (pt == e1.Top) pt.Z = e1.Top.Z;
2131 else if (pt == e2.Bot) pt.Z = e2.Bot.Z;
2132 else if (pt == e2.Top) pt.Z = e2.Top.Z;
2133 else (*m_ZFill)(e1.Bot, e1.Top, e2.Bot, e2.Top, pt);
2134}
2135//------------------------------------------------------------------------------
2136#endif
2137
2138void Clipper::IntersectEdges(TEdge *e1, TEdge *e2, IntPoint &Pt)
2139{
2140 bool e1Contributing = ( e1->OutIdx >= 0 );
2141 bool e2Contributing = ( e2->OutIdx >= 0 );
2142
2143#ifdef use_xyz
2144 SetZ(Pt, *e1, *e2);
2145#endif
2146
2147#ifdef use_lines
2148 //if either edge is on an OPEN path ...
2149 if (e1->WindDelta == 0 || e2->WindDelta == 0)
2150 {
2151 //ignore subject-subject open path intersections UNLESS they
2152 //are both open paths, AND they are both 'contributing maximas' ...
2153 if (e1->WindDelta == 0 && e2->WindDelta == 0) return;
2154
2155 //if intersecting a subj line with a subj poly ...
2156 else if (e1->PolyTyp == e2->PolyTyp &&
2157 e1->WindDelta != e2->WindDelta && m_ClipType == ctUnion)
2158 {
2159 if (e1->WindDelta == 0)
2160 {
2161 if (e2Contributing)
2162 {
2163 AddOutPt(e1, Pt);
2164 if (e1Contributing) e1->OutIdx = Unassigned;
2165 }
2166 }
2167 else
2168 {
2169 if (e1Contributing)
2170 {
2171 AddOutPt(e2, Pt);
2172 if (e2Contributing) e2->OutIdx = Unassigned;
2173 }
2174 }
2175 }
2176 else if (e1->PolyTyp != e2->PolyTyp)
2177 {
2178 //toggle subj open path OutIdx on/off when Abs(clip.WndCnt) == 1 ...
2179 if ((e1->WindDelta == 0) && abs(e2->WindCnt) == 1 &&
2180 (m_ClipType != ctUnion || e2->WindCnt2 == 0))
2181 {
2182 AddOutPt(e1, Pt);
2183 if (e1Contributing) e1->OutIdx = Unassigned;
2184 }
2185 else if ((e2->WindDelta == 0) && (abs(e1->WindCnt) == 1) &&
2186 (m_ClipType != ctUnion || e1->WindCnt2 == 0))
2187 {
2188 AddOutPt(e2, Pt);
2189 if (e2Contributing) e2->OutIdx = Unassigned;
2190 }
2191 }
2192 return;
2193 }
2194#endif
2195
2196 //update winding counts...
2197 //assumes that e1 will be to the Right of e2 ABOVE the intersection
2198 if ( e1->PolyTyp == e2->PolyTyp )
2199 {
2200 if ( IsEvenOddFillType( *e1) )
2201 {
2202 int oldE1WindCnt = e1->WindCnt;
2203 e1->WindCnt = e2->WindCnt;
2204 e2->WindCnt = oldE1WindCnt;
2205 } else
2206 {
2207 if (e1->WindCnt + e2->WindDelta == 0 ) e1->WindCnt = -e1->WindCnt;
2208 else e1->WindCnt += e2->WindDelta;
2209 if ( e2->WindCnt - e1->WindDelta == 0 ) e2->WindCnt = -e2->WindCnt;
2210 else e2->WindCnt -= e1->WindDelta;
2211 }
2212 } else
2213 {
2214 if (!IsEvenOddFillType(*e2)) e1->WindCnt2 += e2->WindDelta;
2215 else e1->WindCnt2 = ( e1->WindCnt2 == 0 ) ? 1 : 0;
2216 if (!IsEvenOddFillType(*e1)) e2->WindCnt2 -= e1->WindDelta;
2217 else e2->WindCnt2 = ( e2->WindCnt2 == 0 ) ? 1 : 0;
2218 }
2219
2220 PolyFillType e1FillType, e2FillType, e1FillType2, e2FillType2;
2221 if (e1->PolyTyp == ptSubject)
2222 {
2223 e1FillType = m_SubjFillType;
2224 e1FillType2 = m_ClipFillType;
2225 } else
2226 {
2227 e1FillType = m_ClipFillType;
2228 e1FillType2 = m_SubjFillType;
2229 }
2230 if (e2->PolyTyp == ptSubject)
2231 {
2232 e2FillType = m_SubjFillType;
2233 e2FillType2 = m_ClipFillType;
2234 } else
2235 {
2236 e2FillType = m_ClipFillType;
2237 e2FillType2 = m_SubjFillType;
2238 }
2239
2240 cInt e1Wc, e2Wc;
2241 switch (e1FillType)
2242 {
2243 case pftPositive: e1Wc = e1->WindCnt; break;
2244 case pftNegative: e1Wc = -e1->WindCnt; break;
2245 default: e1Wc = Abs(e1->WindCnt);
2246 }
2247 switch(e2FillType)
2248 {
2249 case pftPositive: e2Wc = e2->WindCnt; break;
2250 case pftNegative: e2Wc = -e2->WindCnt; break;
2251 default: e2Wc = Abs(e2->WindCnt);
2252 }
2253
2254 if ( e1Contributing && e2Contributing )
2255 {
2256 if ((e1Wc != 0 && e1Wc != 1) || (e2Wc != 0 && e2Wc != 1) ||
2257 (e1->PolyTyp != e2->PolyTyp && m_ClipType != ctXor) )
2258 {
2259 AddLocalMaxPoly(e1, e2, Pt);
2260 }
2261 else
2262 {
2263 AddOutPt(e1, Pt);
2264 AddOutPt(e2, Pt);
2265 SwapSides( *e1 , *e2 );
2266 SwapPolyIndexes( *e1 , *e2 );
2267 }
2268 }
2269 else if ( e1Contributing )
2270 {
2271 if (e2Wc == 0 || e2Wc == 1)
2272 {
2273 AddOutPt(e1, Pt);
2274 SwapSides(*e1, *e2);
2275 SwapPolyIndexes(*e1, *e2);
2276 }
2277 }
2278 else if ( e2Contributing )
2279 {
2280 if (e1Wc == 0 || e1Wc == 1)
2281 {
2282 AddOutPt(e2, Pt);
2283 SwapSides(*e1, *e2);
2284 SwapPolyIndexes(*e1, *e2);
2285 }
2286 }
2287 else if ( (e1Wc == 0 || e1Wc == 1) && (e2Wc == 0 || e2Wc == 1))
2288 {
2289 //neither edge is currently contributing ...
2290
2291 cInt e1Wc2, e2Wc2;
2292 switch (e1FillType2)
2293 {
2294 case pftPositive: e1Wc2 = e1->WindCnt2; break;
2295 case pftNegative : e1Wc2 = -e1->WindCnt2; break;
2296 default: e1Wc2 = Abs(e1->WindCnt2);
2297 }
2298 switch (e2FillType2)
2299 {
2300 case pftPositive: e2Wc2 = e2->WindCnt2; break;
2301 case pftNegative: e2Wc2 = -e2->WindCnt2; break;
2302 default: e2Wc2 = Abs(e2->WindCnt2);
2303 }
2304
2305 if (e1->PolyTyp != e2->PolyTyp)
2306 {
2307 AddLocalMinPoly(e1, e2, Pt);
2308 }
2309 else if (e1Wc == 1 && e2Wc == 1)
2310 switch( m_ClipType ) {
2311 case ctIntersection:
2312 if (e1Wc2 > 0 && e2Wc2 > 0)
2313 AddLocalMinPoly(e1, e2, Pt);
2314 break;
2315 case ctUnion:
2316 if ( e1Wc2 <= 0 && e2Wc2 <= 0 )
2317 AddLocalMinPoly(e1, e2, Pt);
2318 break;
2319 case ctDifference:
2320 if (((e1->PolyTyp == ptClip) && (e1Wc2 > 0) && (e2Wc2 > 0)) ||
2321 ((e1->PolyTyp == ptSubject) && (e1Wc2 <= 0) && (e2Wc2 <= 0)))
2322 AddLocalMinPoly(e1, e2, Pt);
2323 break;
2324 case ctXor:
2325 AddLocalMinPoly(e1, e2, Pt);
2326 }
2327 else
2328 SwapSides( *e1, *e2 );
2329 }
2330}
2331//------------------------------------------------------------------------------
2332
2333void Clipper::SetHoleState(TEdge *e, OutRec *outrec)
2334{
2335 TEdge *e2 = e->PrevInAEL;
2336 TEdge *eTmp = 0;
2337 while (e2)
2338 {
2339 if (e2->OutIdx >= 0 && e2->WindDelta != 0)
2340 {
2341 if (!eTmp) eTmp = e2;
2342 else if (eTmp->OutIdx == e2->OutIdx) eTmp = 0;
2343 }
2344 e2 = e2->PrevInAEL;
2345 }
2346 if (!eTmp)
2347 {
2348 outrec->FirstLeft = 0;
2349 outrec->IsHole = false;
2350 }
2351 else
2352 {
2353 outrec->FirstLeft = m_PolyOuts[eTmp->OutIdx];
2354 outrec->IsHole = !outrec->FirstLeft->IsHole;
2355 }
2356}
2357//------------------------------------------------------------------------------
2358
2359OutRec* GetLowermostRec(OutRec *outRec1, OutRec *outRec2)
2360{
2361 //work out which polygon fragment has the correct hole state ...
2362 if (!outRec1->BottomPt)
2363 outRec1->BottomPt = GetBottomPt(outRec1->Pts);
2364 if (!outRec2->BottomPt)
2365 outRec2->BottomPt = GetBottomPt(outRec2->Pts);
2366 OutPt *OutPt1 = outRec1->BottomPt;
2367 OutPt *OutPt2 = outRec2->BottomPt;
2368 if (OutPt1->Pt.Y > OutPt2->Pt.Y) return outRec1;
2369 else if (OutPt1->Pt.Y < OutPt2->Pt.Y) return outRec2;
2370 else if (OutPt1->Pt.X < OutPt2->Pt.X) return outRec1;
2371 else if (OutPt1->Pt.X > OutPt2->Pt.X) return outRec2;
2372 else if (OutPt1->Next == OutPt1) return outRec2;
2373 else if (OutPt2->Next == OutPt2) return outRec1;
2374 else if (FirstIsBottomPt(OutPt1, OutPt2)) return outRec1;
2375 else return outRec2;
2376}
2377//------------------------------------------------------------------------------
2378
2379bool OutRec1RightOfOutRec2(OutRec* outRec1, OutRec* outRec2)
2380{
2381 do
2382 {
2383 outRec1 = outRec1->FirstLeft;
2384 if (outRec1 == outRec2) return true;
2385 } while (outRec1);
2386 return false;
2387}
2388//------------------------------------------------------------------------------
2389
2390OutRec* Clipper::GetOutRec(int Idx)
2391{
2392 OutRec* outrec = m_PolyOuts[Idx];
2393 while (outrec != m_PolyOuts[outrec->Idx])
2394 outrec = m_PolyOuts[outrec->Idx];
2395 return outrec;
2396}
2397//------------------------------------------------------------------------------
2398
2399void Clipper::AppendPolygon(TEdge *e1, TEdge *e2)
2400{
2401 //get the start and ends of both output polygons ...
2402 OutRec *outRec1 = m_PolyOuts[e1->OutIdx];
2403 OutRec *outRec2 = m_PolyOuts[e2->OutIdx];
2404
2405 OutRec *holeStateRec;
2406 if (OutRec1RightOfOutRec2(outRec1, outRec2))
2407 holeStateRec = outRec2;
2408 else if (OutRec1RightOfOutRec2(outRec2, outRec1))
2409 holeStateRec = outRec1;
2410 else
2411 holeStateRec = GetLowermostRec(outRec1, outRec2);
2412
2413 //get the start and ends of both output polygons and
2414 //join e2 poly onto e1 poly and delete pointers to e2 ...
2415
2416 OutPt* p1_lft = outRec1->Pts;
2417 OutPt* p1_rt = p1_lft->Prev;
2418 OutPt* p2_lft = outRec2->Pts;
2419 OutPt* p2_rt = p2_lft->Prev;
2420
2421 //join e2 poly onto e1 poly and delete pointers to e2 ...
2422 if( e1->Side == esLeft )
2423 {
2424 if( e2->Side == esLeft )
2425 {
2426 //z y x a b c
2427 ReversePolyPtLinks(p2_lft);
2428 p2_lft->Next = p1_lft;
2429 p1_lft->Prev = p2_lft;
2430 p1_rt->Next = p2_rt;
2431 p2_rt->Prev = p1_rt;
2432 outRec1->Pts = p2_rt;
2433 } else
2434 {
2435 //x y z a b c
2436 p2_rt->Next = p1_lft;
2437 p1_lft->Prev = p2_rt;
2438 p2_lft->Prev = p1_rt;
2439 p1_rt->Next = p2_lft;
2440 outRec1->Pts = p2_lft;
2441 }
2442 } else
2443 {
2444 if( e2->Side == esRight )
2445 {
2446 //a b c z y x
2447 ReversePolyPtLinks(p2_lft);
2448 p1_rt->Next = p2_rt;
2449 p2_rt->Prev = p1_rt;
2450 p2_lft->Next = p1_lft;
2451 p1_lft->Prev = p2_lft;
2452 } else
2453 {
2454 //a b c x y z
2455 p1_rt->Next = p2_lft;
2456 p2_lft->Prev = p1_rt;
2457 p1_lft->Prev = p2_rt;
2458 p2_rt->Next = p1_lft;
2459 }
2460 }
2461
2462 outRec1->BottomPt = 0;
2463 if (holeStateRec == outRec2)
2464 {
2465 if (outRec2->FirstLeft != outRec1)
2466 outRec1->FirstLeft = outRec2->FirstLeft;
2467 outRec1->IsHole = outRec2->IsHole;
2468 }
2469 outRec2->Pts = 0;
2470 outRec2->BottomPt = 0;
2471 outRec2->FirstLeft = outRec1;
2472
2473 int OKIdx = e1->OutIdx;
2474 int ObsoleteIdx = e2->OutIdx;
2475
2476 e1->OutIdx = Unassigned; //nb: safe because we only get here via AddLocalMaxPoly
2477 e2->OutIdx = Unassigned;
2478
2479 TEdge* e = m_ActiveEdges;
2480 while( e )
2481 {
2482 if( e->OutIdx == ObsoleteIdx )
2483 {
2484 e->OutIdx = OKIdx;
2485 e->Side = e1->Side;
2486 break;
2487 }
2488 e = e->NextInAEL;
2489 }
2490
2491 outRec2->Idx = outRec1->Idx;
2492}
2493//------------------------------------------------------------------------------
2494
2495OutPt* Clipper::AddOutPt(TEdge *e, const IntPoint &pt)
2496{
2497 if( e->OutIdx < 0 )
2498 {
2499 OutRec *outRec = CreateOutRec();
2500 outRec->IsOpen = (e->WindDelta == 0);
2501 OutPt* newOp = new OutPt;
2502 outRec->Pts = newOp;
2503 newOp->Idx = outRec->Idx;
2504 newOp->Pt = pt;
2505 newOp->Next = newOp;
2506 newOp->Prev = newOp;
2507 if (!outRec->IsOpen)
2508 SetHoleState(e, outRec);
2509 e->OutIdx = outRec->Idx;
2510 return newOp;
2511 } else
2512 {
2513 OutRec *outRec = m_PolyOuts[e->OutIdx];
2514 //OutRec.Pts is the 'Left-most' point & OutRec.Pts.Prev is the 'Right-most'
2515 OutPt* op = outRec->Pts;
2516
2517 bool ToFront = (e->Side == esLeft);
2518 if (ToFront && (pt == op->Pt)) return op;
2519 else if (!ToFront && (pt == op->Prev->Pt)) return op->Prev;
2520
2521 OutPt* newOp = new OutPt;
2522 newOp->Idx = outRec->Idx;
2523 newOp->Pt = pt;
2524 newOp->Next = op;
2525 newOp->Prev = op->Prev;
2526 newOp->Prev->Next = newOp;
2527 op->Prev = newOp;
2528 if (ToFront) outRec->Pts = newOp;
2529 return newOp;
2530 }
2531}
2532//------------------------------------------------------------------------------
2533
2534OutPt* Clipper::GetLastOutPt(TEdge *e)
2535{
2536 OutRec *outRec = m_PolyOuts[e->OutIdx];
2537 if (e->Side == esLeft)
2538 return outRec->Pts;
2539 else
2540 return outRec->Pts->Prev;
2541}
2542//------------------------------------------------------------------------------
2543
2544void Clipper::ProcessHorizontals()
2545{
2546 TEdge* horzEdge;
2547 while (PopEdgeFromSEL(horzEdge))
2548 ProcessHorizontal(horzEdge);
2549}
2550//------------------------------------------------------------------------------
2551
2552inline bool IsMinima(TEdge *e)
2553{
2554 return e && (e->Prev->NextInLML != e) && (e->Next->NextInLML != e);
2555}
2556//------------------------------------------------------------------------------
2557
2558inline bool IsMaxima(TEdge *e, const cInt Y)
2559{
2560 return e && e->Top.Y == Y && !e->NextInLML;
2561}
2562//------------------------------------------------------------------------------
2563
2564inline bool IsIntermediate(TEdge *e, const cInt Y)
2565{
2566 return e->Top.Y == Y && e->NextInLML;
2567}
2568//------------------------------------------------------------------------------
2569
2570TEdge *GetMaximaPair(TEdge *e)
2571{
2572 if ((e->Next->Top == e->Top) && !e->Next->NextInLML)
2573 return e->Next;
2574 else if ((e->Prev->Top == e->Top) && !e->Prev->NextInLML)
2575 return e->Prev;
2576 else return 0;
2577}
2578//------------------------------------------------------------------------------
2579
2580TEdge *GetMaximaPairEx(TEdge *e)
2581{
2582 //as GetMaximaPair() but returns 0 if MaxPair isn't in AEL (unless it's horizontal)
2583 TEdge* result = GetMaximaPair(e);
2584 if (result && (result->OutIdx == Skip ||
2585 (result->NextInAEL == result->PrevInAEL && !IsHorizontal(*result)))) return 0;
2586 return result;
2587}
2588//------------------------------------------------------------------------------
2589
2590void Clipper::SwapPositionsInSEL(TEdge *Edge1, TEdge *Edge2)
2591{
2592 if( !( Edge1->NextInSEL ) && !( Edge1->PrevInSEL ) ) return;
2593 if( !( Edge2->NextInSEL ) && !( Edge2->PrevInSEL ) ) return;
2594
2595 if( Edge1->NextInSEL == Edge2 )
2596 {
2597 TEdge* Next = Edge2->NextInSEL;
2598 if( Next ) Next->PrevInSEL = Edge1;
2599 TEdge* Prev = Edge1->PrevInSEL;
2600 if( Prev ) Prev->NextInSEL = Edge2;
2601 Edge2->PrevInSEL = Prev;
2602 Edge2->NextInSEL = Edge1;
2603 Edge1->PrevInSEL = Edge2;
2604 Edge1->NextInSEL = Next;
2605 }
2606 else if( Edge2->NextInSEL == Edge1 )
2607 {
2608 TEdge* Next = Edge1->NextInSEL;
2609 if( Next ) Next->PrevInSEL = Edge2;
2610 TEdge* Prev = Edge2->PrevInSEL;
2611 if( Prev ) Prev->NextInSEL = Edge1;
2612 Edge1->PrevInSEL = Prev;
2613 Edge1->NextInSEL = Edge2;
2614 Edge2->PrevInSEL = Edge1;
2615 Edge2->NextInSEL = Next;
2616 }
2617 else
2618 {
2619 TEdge* Next = Edge1->NextInSEL;
2620 TEdge* Prev = Edge1->PrevInSEL;
2621 Edge1->NextInSEL = Edge2->NextInSEL;
2622 if( Edge1->NextInSEL ) Edge1->NextInSEL->PrevInSEL = Edge1;
2623 Edge1->PrevInSEL = Edge2->PrevInSEL;
2624 if( Edge1->PrevInSEL ) Edge1->PrevInSEL->NextInSEL = Edge1;
2625 Edge2->NextInSEL = Next;
2626 if( Edge2->NextInSEL ) Edge2->NextInSEL->PrevInSEL = Edge2;
2627 Edge2->PrevInSEL = Prev;
2628 if( Edge2->PrevInSEL ) Edge2->PrevInSEL->NextInSEL = Edge2;
2629 }
2630
2631 if( !Edge1->PrevInSEL ) m_SortedEdges = Edge1;
2632 else if( !Edge2->PrevInSEL ) m_SortedEdges = Edge2;
2633}
2634//------------------------------------------------------------------------------
2635
2636TEdge* GetNextInAEL(TEdge *e, Direction dir)
2637{
2638 return dir == dLeftToRight ? e->NextInAEL : e->PrevInAEL;
2639}
2640//------------------------------------------------------------------------------
2641
2642void GetHorzDirection(TEdge& HorzEdge, Direction& Dir, cInt& Left, cInt& Right)
2643{
2644 if (HorzEdge.Bot.X < HorzEdge.Top.X)
2645 {
2646 Left = HorzEdge.Bot.X;
2647 Right = HorzEdge.Top.X;
2648 Dir = dLeftToRight;
2649 } else
2650 {
2651 Left = HorzEdge.Top.X;
2652 Right = HorzEdge.Bot.X;
2653 Dir = dRightToLeft;
2654 }
2655}
2656//------------------------------------------------------------------------
2657
2658/*******************************************************************************
2659* Notes: Horizontal edges (HEs) at scanline intersections (ie at the Top or *
2660* Bottom of a scanbeam) are processed as if layered. The order in which HEs *
2661* are processed doesn't matter. HEs intersect with other HE Bot.Xs only [#] *
2662* (or they could intersect with Top.Xs only, ie EITHER Bot.Xs OR Top.Xs), *
2663* and with other non-horizontal edges [*]. Once these intersections are *
2664* processed, intermediate HEs then 'promote' the Edge above (NextInLML) into *
2665* the AEL. These 'promoted' edges may in turn intersect [%] with other HEs. *
2666*******************************************************************************/
2667
2668void Clipper::ProcessHorizontal(TEdge *horzEdge)
2669{
2670 Direction dir;
2671 cInt horzLeft, horzRight;
2672 bool IsOpen = (horzEdge->WindDelta == 0);
2673
2674 GetHorzDirection(*horzEdge, dir, horzLeft, horzRight);
2675
2676 TEdge* eLastHorz = horzEdge, *eMaxPair = 0;
2677 while (eLastHorz->NextInLML && IsHorizontal(*eLastHorz->NextInLML))
2678 eLastHorz = eLastHorz->NextInLML;
2679 if (!eLastHorz->NextInLML)
2680 eMaxPair = GetMaximaPair(eLastHorz);
2681
2682 MaximaList::const_iterator maxIt;
2683 MaximaList::const_reverse_iterator maxRit;
2684 if (m_Maxima.size() > 0)
2685 {
2686 //get the first maxima in range (X) ...
2687 if (dir == dLeftToRight)
2688 {
2689 maxIt = m_Maxima.begin();
2690 while (maxIt != m_Maxima.end() && *maxIt <= horzEdge->Bot.X) maxIt++;
2691 if (maxIt != m_Maxima.end() && *maxIt >= eLastHorz->Top.X)
2692 maxIt = m_Maxima.end();
2693 }
2694 else
2695 {
2696 maxRit = m_Maxima.rbegin();
2697 while (maxRit != m_Maxima.rend() && *maxRit > horzEdge->Bot.X) maxRit++;
2698 if (maxRit != m_Maxima.rend() && *maxRit <= eLastHorz->Top.X)
2699 maxRit = m_Maxima.rend();
2700 }
2701 }
2702
2703 OutPt* op1 = 0;
2704
2705 for (;;) //loop through consec. horizontal edges
2706 {
2707
2708 bool IsLastHorz = (horzEdge == eLastHorz);
2709 TEdge* e = GetNextInAEL(horzEdge, dir);
2710 while(e)
2711 {
2712
2713 //this code block inserts extra coords into horizontal edges (in output
2714 //polygons) whereever maxima touch these horizontal edges. This helps
2715 //'simplifying' polygons (ie if the Simplify property is set).
2716 if (m_Maxima.size() > 0)
2717 {
2718 if (dir == dLeftToRight)
2719 {
2720 while (maxIt != m_Maxima.end() && *maxIt < e->Curr.X)
2721 {
2722 if (horzEdge->OutIdx >= 0 && !IsOpen)
2723 AddOutPt(horzEdge, IntPoint(*maxIt, horzEdge->Bot.Y));
2724 maxIt++;
2725 }
2726 }
2727 else
2728 {
2729 while (maxRit != m_Maxima.rend() && *maxRit > e->Curr.X)
2730 {
2731 if (horzEdge->OutIdx >= 0 && !IsOpen)
2732 AddOutPt(horzEdge, IntPoint(*maxRit, horzEdge->Bot.Y));
2733 maxRit++;
2734 }
2735 }
2736 };
2737
2738 if ((dir == dLeftToRight && e->Curr.X > horzRight) ||
2739 (dir == dRightToLeft && e->Curr.X < horzLeft)) break;
2740
2741 //Also break if we've got to the end of an intermediate horizontal edge ...
2742 //nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal.
2743 if (e->Curr.X == horzEdge->Top.X && horzEdge->NextInLML &&
2744 e->Dx < horzEdge->NextInLML->Dx) break;
2745
2746 if (horzEdge->OutIdx >= 0 && !IsOpen) //note: may be done multiple times
2747 {
2748#ifdef use_xyz
2749 if (dir == dLeftToRight) SetZ(e->Curr, *horzEdge, *e);
2750 else SetZ(e->Curr, *e, *horzEdge);
2751#endif
2752 op1 = AddOutPt(horzEdge, e->Curr);
2753 TEdge* eNextHorz = m_SortedEdges;
2754 while (eNextHorz)
2755 {
2756 if (eNextHorz->OutIdx >= 0 &&
2757 HorzSegmentsOverlap(horzEdge->Bot.X,
2758 horzEdge->Top.X, eNextHorz->Bot.X, eNextHorz->Top.X))
2759 {
2760 OutPt* op2 = GetLastOutPt(eNextHorz);
2761 AddJoin(op2, op1, eNextHorz->Top);
2762 }
2763 eNextHorz = eNextHorz->NextInSEL;
2764 }
2765 AddGhostJoin(op1, horzEdge->Bot);
2766 }
2767
2768 //OK, so far we're still in range of the horizontal Edge but make sure
2769 //we're at the last of consec. horizontals when matching with eMaxPair
2770 if(e == eMaxPair && IsLastHorz)
2771 {
2772 if (horzEdge->OutIdx >= 0)
2773 AddLocalMaxPoly(horzEdge, eMaxPair, horzEdge->Top);
2774 DeleteFromAEL(horzEdge);
2775 DeleteFromAEL(eMaxPair);
2776 return;
2777 }
2778
2779 if(dir == dLeftToRight)
2780 {
2781 IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y);
2782 IntersectEdges(horzEdge, e, Pt);
2783 }
2784 else
2785 {
2786 IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y);
2787 IntersectEdges( e, horzEdge, Pt);
2788 }
2789 TEdge* eNext = GetNextInAEL(e, dir);
2790 SwapPositionsInAEL( horzEdge, e );
2791 e = eNext;
2792 } //end while(e)
2793
2794 //Break out of loop if HorzEdge.NextInLML is not also horizontal ...
2795 if (!horzEdge->NextInLML || !IsHorizontal(*horzEdge->NextInLML)) break;
2796
2797 UpdateEdgeIntoAEL(horzEdge);
2798 if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Bot);
2799 GetHorzDirection(*horzEdge, dir, horzLeft, horzRight);
2800
2801 } //end for (;;)
2802
2803 if (horzEdge->OutIdx >= 0 && !op1)
2804 {
2805 op1 = GetLastOutPt(horzEdge);
2806 TEdge* eNextHorz = m_SortedEdges;
2807 while (eNextHorz)
2808 {
2809 if (eNextHorz->OutIdx >= 0 &&
2810 HorzSegmentsOverlap(horzEdge->Bot.X,
2811 horzEdge->Top.X, eNextHorz->Bot.X, eNextHorz->Top.X))
2812 {
2813 OutPt* op2 = GetLastOutPt(eNextHorz);
2814 AddJoin(op2, op1, eNextHorz->Top);
2815 }
2816 eNextHorz = eNextHorz->NextInSEL;
2817 }
2818 AddGhostJoin(op1, horzEdge->Top);
2819 }
2820
2821 if (horzEdge->NextInLML)
2822 {
2823 if(horzEdge->OutIdx >= 0)
2824 {
2825 op1 = AddOutPt( horzEdge, horzEdge->Top);
2826 UpdateEdgeIntoAEL(horzEdge);
2827 if (horzEdge->WindDelta == 0) return;
2828 //nb: HorzEdge is no longer horizontal here
2829 TEdge* ePrev = horzEdge->PrevInAEL;
2830 TEdge* eNext = horzEdge->NextInAEL;
2831 if (ePrev && ePrev->Curr.X == horzEdge->Bot.X &&
2832 ePrev->Curr.Y == horzEdge->Bot.Y && ePrev->WindDelta != 0 &&
2833 (ePrev->OutIdx >= 0 && ePrev->Curr.Y > ePrev->Top.Y &&
2834 SlopesEqual(*horzEdge, *ePrev, m_UseFullRange)))
2835 {
2836 OutPt* op2 = AddOutPt(ePrev, horzEdge->Bot);
2837 AddJoin(op1, op2, horzEdge->Top);
2838 }
2839 else if (eNext && eNext->Curr.X == horzEdge->Bot.X &&
2840 eNext->Curr.Y == horzEdge->Bot.Y && eNext->WindDelta != 0 &&
2841 eNext->OutIdx >= 0 && eNext->Curr.Y > eNext->Top.Y &&
2842 SlopesEqual(*horzEdge, *eNext, m_UseFullRange))
2843 {
2844 OutPt* op2 = AddOutPt(eNext, horzEdge->Bot);
2845 AddJoin(op1, op2, horzEdge->Top);
2846 }
2847 }
2848 else
2849 UpdateEdgeIntoAEL(horzEdge);
2850 }
2851 else
2852 {
2853 if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Top);
2854 DeleteFromAEL(horzEdge);
2855 }
2856}
2857//------------------------------------------------------------------------------
2858
2859bool Clipper::ProcessIntersections(const cInt topY)
2860{
2861 if( !m_ActiveEdges ) return true;
2862 CLIPPER_TRY {
2863 BuildIntersectList(topY);
2864 size_t IlSize = m_IntersectList.size();
2865 if (IlSize == 0) return true;
2866 if (IlSize == 1 || FixupIntersectionOrder()) ProcessIntersectList();
2867 else return false;
2868 }
2869 CLIPPER_CATCH(...)
2870 {
2871 m_SortedEdges = 0;
2872 DisposeIntersectNodes();
2873 CLIPPER_THROW(clipperException("ProcessIntersections error"));
2874 }
2875 m_SortedEdges = 0;
2876 return true;
2877}
2878//------------------------------------------------------------------------------
2879
2880void Clipper::DisposeIntersectNodes()
2881{
2882 for (size_t i = 0; i < m_IntersectList.size(); ++i )
2883 delete m_IntersectList[i];
2884 m_IntersectList.clear();
2885}
2886//------------------------------------------------------------------------------
2887
2888void Clipper::BuildIntersectList(const cInt topY)
2889{
2890 if ( !m_ActiveEdges ) return;
2891
2892 //prepare for sorting ...
2893 TEdge* e = m_ActiveEdges;
2894 m_SortedEdges = e;
2895 while( e )
2896 {
2897 e->PrevInSEL = e->PrevInAEL;
2898 e->NextInSEL = e->NextInAEL;
2899 e->Curr.X = TopX( *e, topY );
2900 e = e->NextInAEL;
2901 }
2902
2903 //bubblesort ...
2904 bool isModified;
2905 do
2906 {
2907 isModified = false;
2908 e = m_SortedEdges;
2909 while( e->NextInSEL )
2910 {
2911 TEdge *eNext = e->NextInSEL;
2912 IntPoint Pt;
2913 if(e->Curr.X > eNext->Curr.X)
2914 {
2915 IntersectPoint(*e, *eNext, Pt);
2916 if (Pt.Y < topY) Pt = IntPoint(TopX(*e, topY), topY);
2917 IntersectNode * newNode = new IntersectNode;
2918 newNode->Edge1 = e;
2919 newNode->Edge2 = eNext;
2920 newNode->Pt = Pt;
2921 m_IntersectList.push_back(newNode);
2922
2923 SwapPositionsInSEL(e, eNext);
2924 isModified = true;
2925 }
2926 else
2927 e = eNext;
2928 }
2929 if( e->PrevInSEL ) e->PrevInSEL->NextInSEL = 0;
2930 else break;
2931 }
2932 while ( isModified );
2933 m_SortedEdges = 0; //important
2934}
2935//------------------------------------------------------------------------------
2936
2937
2938void Clipper::ProcessIntersectList()
2939{
2940 for (size_t i = 0; i < m_IntersectList.size(); ++i)
2941 {
2942 IntersectNode* iNode = m_IntersectList[i];
2943 {
2944 IntersectEdges( iNode->Edge1, iNode->Edge2, iNode->Pt);
2945 SwapPositionsInAEL( iNode->Edge1 , iNode->Edge2 );
2946 }
2947 delete iNode;
2948 }
2949 m_IntersectList.clear();
2950}
2951//------------------------------------------------------------------------------
2952
2953bool IntersectListSort(IntersectNode* node1, IntersectNode* node2)
2954{
2955 return node2->Pt.Y < node1->Pt.Y;
2956}
2957//------------------------------------------------------------------------------
2958
2959inline bool EdgesAdjacent(const IntersectNode &inode)
2960{
2961 return (inode.Edge1->NextInSEL == inode.Edge2) ||
2962 (inode.Edge1->PrevInSEL == inode.Edge2);
2963}
2964//------------------------------------------------------------------------------
2965
2966bool Clipper::FixupIntersectionOrder()
2967{
2968 //pre-condition: intersections are sorted Bottom-most first.
2969 //Now it's crucial that intersections are made only between adjacent edges,
2970 //so to ensure this the order of intersections may need adjusting ...
2971 CopyAELToSEL();
2972 std::sort(m_IntersectList.begin(), m_IntersectList.end(), IntersectListSort);
2973 size_t cnt = m_IntersectList.size();
2974 for (size_t i = 0; i < cnt; ++i)
2975 {
2976 if (!EdgesAdjacent(*m_IntersectList[i]))
2977 {
2978 size_t j = i + 1;
2979 while (j < cnt && !EdgesAdjacent(*m_IntersectList[j])) j++;
2980 if (j == cnt) return false;
2981 std::swap(m_IntersectList[i], m_IntersectList[j]);
2982 }
2983 SwapPositionsInSEL(m_IntersectList[i]->Edge1, m_IntersectList[i]->Edge2);
2984 }
2985 return true;
2986}
2987//------------------------------------------------------------------------------
2988
2989void Clipper::DoMaxima(TEdge *e)
2990{
2991 TEdge* eMaxPair = GetMaximaPairEx(e);
2992 if (!eMaxPair)
2993 {
2994 if (e->OutIdx >= 0)
2995 AddOutPt(e, e->Top);
2996 DeleteFromAEL(e);
2997 return;
2998 }
2999
3000 TEdge* eNext = e->NextInAEL;
3001 while(eNext && eNext != eMaxPair)
3002 {
3003 IntersectEdges(e, eNext, e->Top);
3004 SwapPositionsInAEL(e, eNext);
3005 eNext = e->NextInAEL;
3006 }
3007
3008 if(e->OutIdx == Unassigned && eMaxPair->OutIdx == Unassigned)
3009 {
3010 DeleteFromAEL(e);
3011 DeleteFromAEL(eMaxPair);
3012 }
3013 else if( e->OutIdx >= 0 && eMaxPair->OutIdx >= 0 )
3014 {
3015 if (e->OutIdx >= 0) AddLocalMaxPoly(e, eMaxPair, e->Top);
3016 DeleteFromAEL(e);
3017 DeleteFromAEL(eMaxPair);
3018 }
3019#ifdef use_lines
3020 else if (e->WindDelta == 0)
3021 {
3022 if (e->OutIdx >= 0)
3023 {
3024 AddOutPt(e, e->Top);
3025 e->OutIdx = Unassigned;
3026 }
3027 DeleteFromAEL(e);
3028
3029 if (eMaxPair->OutIdx >= 0)
3030 {
3031 AddOutPt(eMaxPair, e->Top);
3032 eMaxPair->OutIdx = Unassigned;
3033 }
3034 DeleteFromAEL(eMaxPair);
3035 }
3036#endif
3037 else CLIPPER_THROW(clipperException("DoMaxima error"));
3038}
3039//------------------------------------------------------------------------------
3040
3041void Clipper::ProcessEdgesAtTopOfScanbeam(const cInt topY)
3042{
3043 TEdge* e = m_ActiveEdges;
3044 while( e )
3045 {
3046 //1. process maxima, treating them as if they're 'bent' horizontal edges,
3047 // but exclude maxima with horizontal edges. nb: e can't be a horizontal.
3048 bool IsMaximaEdge = IsMaxima(e, topY);
3049
3050 if(IsMaximaEdge)
3051 {
3052 TEdge* eMaxPair = GetMaximaPairEx(e);
3053 IsMaximaEdge = (!eMaxPair || !IsHorizontal(*eMaxPair));
3054 }
3055
3056 if(IsMaximaEdge)
3057 {
3058 if (m_StrictSimple) m_Maxima.push_back(e->Top.X);
3059 TEdge* ePrev = e->PrevInAEL;
3060 DoMaxima(e);
3061 if( !ePrev ) e = m_ActiveEdges;
3062 else e = ePrev->NextInAEL;
3063 }
3064 else
3065 {
3066 //2. promote horizontal edges, otherwise update Curr.X and Curr.Y ...
3067 if (IsIntermediate(e, topY) && IsHorizontal(*e->NextInLML))
3068 {
3069 UpdateEdgeIntoAEL(e);
3070 if (e->OutIdx >= 0)
3071 AddOutPt(e, e->Bot);
3072 AddEdgeToSEL(e);
3073 }
3074 else
3075 {
3076 e->Curr.X = TopX( *e, topY );
3077 e->Curr.Y = topY;
3078#ifdef use_xyz
3079 e->Curr.Z = topY == e->Top.Y ? e->Top.Z : (topY == e->Bot.Y ? e->Bot.Z : 0);
3080#endif
3081 }
3082
3083 //When StrictlySimple and 'e' is being touched by another edge, then
3084 //make sure both edges have a vertex here ...
3085 if (m_StrictSimple)
3086 {
3087 TEdge* ePrev = e->PrevInAEL;
3088 if ((e->OutIdx >= 0) && (e->WindDelta != 0) && ePrev && (ePrev->OutIdx >= 0) &&
3089 (ePrev->Curr.X == e->Curr.X) && (ePrev->WindDelta != 0))
3090 {
3091 IntPoint pt = e->Curr;
3092#ifdef use_xyz
3093 SetZ(pt, *ePrev, *e);
3094#endif
3095 OutPt* op = AddOutPt(ePrev, pt);
3096 OutPt* op2 = AddOutPt(e, pt);
3097 AddJoin(op, op2, pt); //StrictlySimple (type-3) join
3098 }
3099 }
3100
3101 e = e->NextInAEL;
3102 }
3103 }
3104
3105 //3. Process horizontals at the Top of the scanbeam ...
3106 m_Maxima.sort();
3107 ProcessHorizontals();
3108 m_Maxima.clear();
3109
3110 //4. Promote intermediate vertices ...
3111 e = m_ActiveEdges;
3112 while(e)
3113 {
3114 if(IsIntermediate(e, topY))
3115 {
3116 OutPt* op = 0;
3117 if( e->OutIdx >= 0 )
3118 op = AddOutPt(e, e->Top);
3119 UpdateEdgeIntoAEL(e);
3120
3121 //if output polygons share an edge, they'll need joining later ...
3122 TEdge* ePrev = e->PrevInAEL;
3123 TEdge* eNext = e->NextInAEL;
3124 if (ePrev && ePrev->Curr.X == e->Bot.X &&
3125 ePrev->Curr.Y == e->Bot.Y && op &&
3126 ePrev->OutIdx >= 0 && ePrev->Curr.Y > ePrev->Top.Y &&
3127 SlopesEqual(e->Curr, e->Top, ePrev->Curr, ePrev->Top, m_UseFullRange) &&
3128 (e->WindDelta != 0) && (ePrev->WindDelta != 0))
3129 {
3130 OutPt* op2 = AddOutPt(ePrev, e->Bot);
3131 AddJoin(op, op2, e->Top);
3132 }
3133 else if (eNext && eNext->Curr.X == e->Bot.X &&
3134 eNext->Curr.Y == e->Bot.Y && op &&
3135 eNext->OutIdx >= 0 && eNext->Curr.Y > eNext->Top.Y &&
3136 SlopesEqual(e->Curr, e->Top, eNext->Curr, eNext->Top, m_UseFullRange) &&
3137 (e->WindDelta != 0) && (eNext->WindDelta != 0))
3138 {
3139 OutPt* op2 = AddOutPt(eNext, e->Bot);
3140 AddJoin(op, op2, e->Top);
3141 }
3142 }
3143 e = e->NextInAEL;
3144 }
3145}
3146//------------------------------------------------------------------------------
3147
3148void Clipper::FixupOutPolyline(OutRec &outrec)
3149{
3150 OutPt *pp = outrec.Pts;
3151 OutPt *lastPP = pp->Prev;
3152 while (pp != lastPP)
3153 {
3154 pp = pp->Next;
3155 if (pp->Pt == pp->Prev->Pt)
3156 {
3157 if (pp == lastPP) lastPP = pp->Prev;
3158 OutPt *tmpPP = pp->Prev;
3159 tmpPP->Next = pp->Next;
3160 pp->Next->Prev = tmpPP;
3161 delete pp;
3162 pp = tmpPP;
3163 }
3164 }
3165
3166 if (pp == pp->Prev)
3167 {
3168 DisposeOutPts(pp);
3169 outrec.Pts = 0;
3170 return;
3171 }
3172}
3173//------------------------------------------------------------------------------
3174
3175void Clipper::FixupOutPolygon(OutRec &outrec)
3176{
3177 //FixupOutPolygon() - removes duplicate points and simplifies consecutive
3178 //parallel edges by removing the middle vertex.
3179 OutPt *lastOK = 0;
3180 outrec.BottomPt = 0;
3181 OutPt *pp = outrec.Pts;
3182 bool preserveCol = m_PreserveCollinear || m_StrictSimple;
3183
3184 for (;;)
3185 {
3186 if (pp->Prev == pp || pp->Prev == pp->Next)
3187 {
3188 DisposeOutPts(pp);
3189 outrec.Pts = 0;
3190 return;
3191 }
3192
3193 //test for duplicate points and collinear edges ...
3194 if ((pp->Pt == pp->Next->Pt) || (pp->Pt == pp->Prev->Pt) ||
3195 (SlopesEqual(pp->Prev->Pt, pp->Pt, pp->Next->Pt, m_UseFullRange) &&
3196 (!preserveCol || !Pt2IsBetweenPt1AndPt3(pp->Prev->Pt, pp->Pt, pp->Next->Pt))))
3197 {
3198 lastOK = 0;
3199 OutPt *tmp = pp;
3200 pp->Prev->Next = pp->Next;
3201 pp->Next->Prev = pp->Prev;
3202 pp = pp->Prev;
3203 delete tmp;
3204 }
3205 else if (pp == lastOK) break;
3206 else
3207 {
3208 if (!lastOK) lastOK = pp;
3209 pp = pp->Next;
3210 }
3211 }
3212 outrec.Pts = pp;
3213}
3214//------------------------------------------------------------------------------
3215
3216int PointCount(OutPt *Pts)
3217{
3218 if (!Pts) return 0;
3219 int result = 0;
3220 OutPt* p = Pts;
3221 do
3222 {
3223 result++;
3224 p = p->Next;
3225 }
3226 while (p != Pts);
3227 return result;
3228}
3229//------------------------------------------------------------------------------
3230
3231void Clipper::BuildResult(Paths &polys)
3232{
3233 polys.reserve(m_PolyOuts.size());
3234 for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
3235 {
3236 if (!m_PolyOuts[i]->Pts) continue;
3237 Path pg;
3238 OutPt* p = m_PolyOuts[i]->Pts->Prev;
3239 int cnt = PointCount(p);
3240 if (cnt < 2) continue;
3241 pg.reserve(cnt);
3242 for (int i = 0; i < cnt; ++i)
3243 {
3244 pg.push_back(p->Pt);
3245 p = p->Prev;
3246 }
3247 polys.push_back(pg);
3248 }
3249}
3250//------------------------------------------------------------------------------
3251
3252void Clipper::BuildResult2(PolyTree& polytree)
3253{
3254 polytree.Clear();
3255 polytree.AllNodes.reserve(m_PolyOuts.size());
3256 //add each output polygon/contour to polytree ...
3257 for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); i++)
3258 {
3259 OutRec* outRec = m_PolyOuts[i];
3260 int cnt = PointCount(outRec->Pts);
3261 if ((outRec->IsOpen && cnt < 2) || (!outRec->IsOpen && cnt < 3)) continue;
3262 FixHoleLinkage(*outRec);
3263 PolyNode* pn = new PolyNode();
3264 //nb: polytree takes ownership of all the PolyNodes
3265 polytree.AllNodes.push_back(pn);
3266 outRec->PolyNd = pn;
3267 pn->Parent = 0;
3268 pn->Index = 0;
3269 pn->Contour.reserve(cnt);
3270 OutPt *op = outRec->Pts->Prev;
3271 for (int j = 0; j < cnt; j++)
3272 {
3273 pn->Contour.push_back(op->Pt);
3274 op = op->Prev;
3275 }
3276 }
3277
3278 //fixup PolyNode links etc ...
3279 polytree.Childs.reserve(m_PolyOuts.size());
3280 for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); i++)
3281 {
3282 OutRec* outRec = m_PolyOuts[i];
3283 if (!outRec->PolyNd) continue;
3284 if (outRec->IsOpen)
3285 {
3286 outRec->PolyNd->m_IsOpen = true;
3287 polytree.AddChild(*outRec->PolyNd);
3288 }
3289 else if (outRec->FirstLeft && outRec->FirstLeft->PolyNd)
3290 outRec->FirstLeft->PolyNd->AddChild(*outRec->PolyNd);
3291 else
3292 polytree.AddChild(*outRec->PolyNd);
3293 }
3294}
3295//------------------------------------------------------------------------------
3296
3297void SwapIntersectNodes(IntersectNode &int1, IntersectNode &int2)
3298{
3299 //just swap the contents (because fIntersectNodes is a single-linked-list)
3300 IntersectNode inode = int1; //gets a copy of Int1
3301 int1.Edge1 = int2.Edge1;
3302 int1.Edge2 = int2.Edge2;
3303 int1.Pt = int2.Pt;
3304 int2.Edge1 = inode.Edge1;
3305 int2.Edge2 = inode.Edge2;
3306 int2.Pt = inode.Pt;
3307}
3308//------------------------------------------------------------------------------
3309
3310inline bool E2InsertsBeforeE1(TEdge &e1, TEdge &e2)
3311{
3312 if (e2.Curr.X == e1.Curr.X)
3313 {
3314 if (e2.Top.Y > e1.Top.Y)
3315 return e2.Top.X < TopX(e1, e2.Top.Y);
3316 else return e1.Top.X > TopX(e2, e1.Top.Y);
3317 }
3318 else return e2.Curr.X < e1.Curr.X;
3319}
3320//------------------------------------------------------------------------------
3321
3322bool GetOverlap(const cInt a1, const cInt a2, const cInt b1, const cInt b2,
3323 cInt& Left, cInt& Right)
3324{
3325 if (a1 < a2)
3326 {
3327 if (b1 < b2) {Left = std::max(a1,b1); Right = std::min(a2,b2);}
3328 else {Left = std::max(a1,b2); Right = std::min(a2,b1);}
3329 }
3330 else
3331 {
3332 if (b1 < b2) {Left = std::max(a2,b1); Right = std::min(a1,b2);}
3333 else {Left = std::max(a2,b2); Right = std::min(a1,b1);}
3334 }
3335 return Left < Right;
3336}
3337//------------------------------------------------------------------------------
3338
3339inline void UpdateOutPtIdxs(OutRec& outrec)
3340{
3341 OutPt* op = outrec.Pts;
3342 do
3343 {
3344 op->Idx = outrec.Idx;
3345 op = op->Prev;
3346 }
3347 while(op != outrec.Pts);
3348}
3349//------------------------------------------------------------------------------
3350
3351void Clipper::InsertEdgeIntoAEL(TEdge *edge, TEdge* startEdge)
3352{
3353 if(!m_ActiveEdges)
3354 {
3355 edge->PrevInAEL = 0;
3356 edge->NextInAEL = 0;
3357 m_ActiveEdges = edge;
3358 }
3359 else if(!startEdge && E2InsertsBeforeE1(*m_ActiveEdges, *edge))
3360 {
3361 edge->PrevInAEL = 0;
3362 edge->NextInAEL = m_ActiveEdges;
3363 m_ActiveEdges->PrevInAEL = edge;
3364 m_ActiveEdges = edge;
3365 }
3366 else
3367 {
3368 if(!startEdge) startEdge = m_ActiveEdges;
3369 while(startEdge->NextInAEL &&
3370 !E2InsertsBeforeE1(*startEdge->NextInAEL , *edge))
3371 startEdge = startEdge->NextInAEL;
3372 edge->NextInAEL = startEdge->NextInAEL;
3373 if(startEdge->NextInAEL) startEdge->NextInAEL->PrevInAEL = edge;
3374 edge->PrevInAEL = startEdge;
3375 startEdge->NextInAEL = edge;
3376 }
3377}
3378//----------------------------------------------------------------------
3379
3380OutPt* DupOutPt(OutPt* outPt, bool InsertAfter)
3381{
3382 OutPt* result = new OutPt;
3383 result->Pt = outPt->Pt;
3384 result->Idx = outPt->Idx;
3385 if (InsertAfter)
3386 {
3387 result->Next = outPt->Next;
3388 result->Prev = outPt;
3389 outPt->Next->Prev = result;
3390 outPt->Next = result;
3391 }
3392 else
3393 {
3394 result->Prev = outPt->Prev;
3395 result->Next = outPt;
3396 outPt->Prev->Next = result;
3397 outPt->Prev = result;
3398 }
3399 return result;
3400}
3401//------------------------------------------------------------------------------
3402
3403bool JoinHorz(OutPt* op1, OutPt* op1b, OutPt* op2, OutPt* op2b,
3404 const IntPoint Pt, bool DiscardLeft)
3405{
3406 Direction Dir1 = (op1->Pt.X > op1b->Pt.X ? dRightToLeft : dLeftToRight);
3407 Direction Dir2 = (op2->Pt.X > op2b->Pt.X ? dRightToLeft : dLeftToRight);
3408 if (Dir1 == Dir2) return false;
3409
3410 //When DiscardLeft, we want Op1b to be on the Left of Op1, otherwise we
3411 //want Op1b to be on the Right. (And likewise with Op2 and Op2b.)
3412 //So, to facilitate this while inserting Op1b and Op2b ...
3413 //when DiscardLeft, make sure we're AT or RIGHT of Pt before adding Op1b,
3414 //otherwise make sure we're AT or LEFT of Pt. (Likewise with Op2b.)
3415 if (Dir1 == dLeftToRight)
3416 {
3417 while (op1->Next->Pt.X <= Pt.X &&
3418 op1->Next->Pt.X >= op1->Pt.X && op1->Next->Pt.Y == Pt.Y)
3419 op1 = op1->Next;
3420 if (DiscardLeft && (op1->Pt.X != Pt.X)) op1 = op1->Next;
3421 op1b = DupOutPt(op1, !DiscardLeft);
3422 if (op1b->Pt != Pt)
3423 {
3424 op1 = op1b;
3425 op1->Pt = Pt;
3426 op1b = DupOutPt(op1, !DiscardLeft);
3427 }
3428 }
3429 else
3430 {
3431 while (op1->Next->Pt.X >= Pt.X &&
3432 op1->Next->Pt.X <= op1->Pt.X && op1->Next->Pt.Y == Pt.Y)
3433 op1 = op1->Next;
3434 if (!DiscardLeft && (op1->Pt.X != Pt.X)) op1 = op1->Next;
3435 op1b = DupOutPt(op1, DiscardLeft);
3436 if (op1b->Pt != Pt)
3437 {
3438 op1 = op1b;
3439 op1->Pt = Pt;
3440 op1b = DupOutPt(op1, DiscardLeft);
3441 }
3442 }
3443
3444 if (Dir2 == dLeftToRight)
3445 {
3446 while (op2->Next->Pt.X <= Pt.X &&
3447 op2->Next->Pt.X >= op2->Pt.X && op2->Next->Pt.Y == Pt.Y)
3448 op2 = op2->Next;
3449 if (DiscardLeft && (op2->Pt.X != Pt.X)) op2 = op2->Next;
3450 op2b = DupOutPt(op2, !DiscardLeft);
3451 if (op2b->Pt != Pt)
3452 {
3453 op2 = op2b;
3454 op2->Pt = Pt;
3455 op2b = DupOutPt(op2, !DiscardLeft);
3456 };
3457 } else
3458 {
3459 while (op2->Next->Pt.X >= Pt.X &&
3460 op2->Next->Pt.X <= op2->Pt.X && op2->Next->Pt.Y == Pt.Y)
3461 op2 = op2->Next;
3462 if (!DiscardLeft && (op2->Pt.X != Pt.X)) op2 = op2->Next;
3463 op2b = DupOutPt(op2, DiscardLeft);
3464 if (op2b->Pt != Pt)
3465 {
3466 op2 = op2b;
3467 op2->Pt = Pt;
3468 op2b = DupOutPt(op2, DiscardLeft);
3469 };
3470 };
3471
3472 if ((Dir1 == dLeftToRight) == DiscardLeft)
3473 {
3474 op1->Prev = op2;
3475 op2->Next = op1;
3476 op1b->Next = op2b;
3477 op2b->Prev = op1b;
3478 }
3479 else
3480 {
3481 op1->Next = op2;
3482 op2->Prev = op1;
3483 op1b->Prev = op2b;
3484 op2b->Next = op1b;
3485 }
3486 return true;
3487}
3488//------------------------------------------------------------------------------
3489
3490bool Clipper::JoinPoints(Join *j, OutRec* outRec1, OutRec* outRec2)
3491{
3492 OutPt *op1 = j->OutPt1, *op1b;
3493 OutPt *op2 = j->OutPt2, *op2b;
3494
3495 //There are 3 kinds of joins for output polygons ...
3496 //1. Horizontal joins where Join.OutPt1 & Join.OutPt2 are vertices anywhere
3497 //along (horizontal) collinear edges (& Join.OffPt is on the same horizontal).
3498 //2. Non-horizontal joins where Join.OutPt1 & Join.OutPt2 are at the same
3499 //location at the Bottom of the overlapping segment (& Join.OffPt is above).
3500 //3. StrictSimple joins where edges touch but are not collinear and where
3501 //Join.OutPt1, Join.OutPt2 & Join.OffPt all share the same point.
3502 bool isHorizontal = (j->OutPt1->Pt.Y == j->OffPt.Y);
3503
3504 if (isHorizontal && (j->OffPt == j->OutPt1->Pt) &&
3505 (j->OffPt == j->OutPt2->Pt))
3506 {
3507 //Strictly Simple join ...
3508 if (outRec1 != outRec2) return false;
3509 op1b = j->OutPt1->Next;
3510 while (op1b != op1 && (op1b->Pt == j->OffPt))
3511 op1b = op1b->Next;
3512 bool reverse1 = (op1b->Pt.Y > j->OffPt.Y);
3513 op2b = j->OutPt2->Next;
3514 while (op2b != op2 && (op2b->Pt == j->OffPt))
3515 op2b = op2b->Next;
3516 bool reverse2 = (op2b->Pt.Y > j->OffPt.Y);
3517 if (reverse1 == reverse2) return false;
3518 if (reverse1)
3519 {
3520 op1b = DupOutPt(op1, false);
3521 op2b = DupOutPt(op2, true);
3522 op1->Prev = op2;
3523 op2->Next = op1;
3524 op1b->Next = op2b;
3525 op2b->Prev = op1b;
3526 j->OutPt1 = op1;
3527 j->OutPt2 = op1b;
3528 return true;
3529 } else
3530 {
3531 op1b = DupOutPt(op1, true);
3532 op2b = DupOutPt(op2, false);
3533 op1->Next = op2;
3534 op2->Prev = op1;
3535 op1b->Prev = op2b;
3536 op2b->Next = op1b;
3537 j->OutPt1 = op1;
3538 j->OutPt2 = op1b;
3539 return true;
3540 }
3541 }
3542 else if (isHorizontal)
3543 {
3544 //treat horizontal joins differently to non-horizontal joins since with
3545 //them we're not yet sure where the overlapping is. OutPt1.Pt & OutPt2.Pt
3546 //may be anywhere along the horizontal edge.
3547 op1b = op1;
3548 while (op1->Prev->Pt.Y == op1->Pt.Y && op1->Prev != op1b && op1->Prev != op2)
3549 op1 = op1->Prev;
3550 while (op1b->Next->Pt.Y == op1b->Pt.Y && op1b->Next != op1 && op1b->Next != op2)
3551 op1b = op1b->Next;
3552 if (op1b->Next == op1 || op1b->Next == op2) return false; //a flat 'polygon'
3553
3554 op2b = op2;
3555 while (op2->Prev->Pt.Y == op2->Pt.Y && op2->Prev != op2b && op2->Prev != op1b)
3556 op2 = op2->Prev;
3557 while (op2b->Next->Pt.Y == op2b->Pt.Y && op2b->Next != op2 && op2b->Next != op1)
3558 op2b = op2b->Next;
3559 if (op2b->Next == op2 || op2b->Next == op1) return false; //a flat 'polygon'
3560
3561 cInt Left, Right;
3562 //Op1 --> Op1b & Op2 --> Op2b are the extremites of the horizontal edges
3563 if (!GetOverlap(op1->Pt.X, op1b->Pt.X, op2->Pt.X, op2b->Pt.X, Left, Right))
3564 return false;
3565
3566 //DiscardLeftSide: when overlapping edges are joined, a spike will created
3567 //which needs to be cleaned up. However, we don't want Op1 or Op2 caught up
3568 //on the discard Side as either may still be needed for other joins ...
3569 IntPoint Pt;
3570 bool DiscardLeftSide;
3571 if (op1->Pt.X >= Left && op1->Pt.X <= Right)
3572 {
3573 Pt = op1->Pt; DiscardLeftSide = (op1->Pt.X > op1b->Pt.X);
3574 }
3575 else if (op2->Pt.X >= Left&& op2->Pt.X <= Right)
3576 {
3577 Pt = op2->Pt; DiscardLeftSide = (op2->Pt.X > op2b->Pt.X);
3578 }
3579 else if (op1b->Pt.X >= Left && op1b->Pt.X <= Right)
3580 {
3581 Pt = op1b->Pt; DiscardLeftSide = op1b->Pt.X > op1->Pt.X;
3582 }
3583 else
3584 {
3585 Pt = op2b->Pt; DiscardLeftSide = (op2b->Pt.X > op2->Pt.X);
3586 }
3587 j->OutPt1 = op1; j->OutPt2 = op2;
3588 return JoinHorz(op1, op1b, op2, op2b, Pt, DiscardLeftSide);
3589 } else
3590 {
3591 //nb: For non-horizontal joins ...
3592 // 1. Jr.OutPt1.Pt.Y == Jr.OutPt2.Pt.Y
3593 // 2. Jr.OutPt1.Pt > Jr.OffPt.Y
3594
3595 //make sure the polygons are correctly oriented ...
3596 op1b = op1->Next;
3597 while ((op1b->Pt == op1->Pt) && (op1b != op1)) op1b = op1b->Next;
3598 bool Reverse1 = ((op1b->Pt.Y > op1->Pt.Y) ||
3599 !SlopesEqual(op1->Pt, op1b->Pt, j->OffPt, m_UseFullRange));
3600 if (Reverse1)
3601 {
3602 op1b = op1->Prev;
3603 while ((op1b->Pt == op1->Pt) && (op1b != op1)) op1b = op1b->Prev;
3604 if ((op1b->Pt.Y > op1->Pt.Y) ||
3605 !SlopesEqual(op1->Pt, op1b->Pt, j->OffPt, m_UseFullRange)) return false;
3606 };
3607 op2b = op2->Next;
3608 while ((op2b->Pt == op2->Pt) && (op2b != op2))op2b = op2b->Next;
3609 bool Reverse2 = ((op2b->Pt.Y > op2->Pt.Y) ||
3610 !SlopesEqual(op2->Pt, op2b->Pt, j->OffPt, m_UseFullRange));
3611 if (Reverse2)
3612 {
3613 op2b = op2->Prev;
3614 while ((op2b->Pt == op2->Pt) && (op2b != op2)) op2b = op2b->Prev;
3615 if ((op2b->Pt.Y > op2->Pt.Y) ||
3616 !SlopesEqual(op2->Pt, op2b->Pt, j->OffPt, m_UseFullRange)) return false;
3617 }
3618
3619 if ((op1b == op1) || (op2b == op2) || (op1b == op2b) ||
3620 ((outRec1 == outRec2) && (Reverse1 == Reverse2))) return false;
3621
3622 if (Reverse1)
3623 {
3624 op1b = DupOutPt(op1, false);
3625 op2b = DupOutPt(op2, true);
3626 op1->Prev = op2;
3627 op2->Next = op1;
3628 op1b->Next = op2b;
3629 op2b->Prev = op1b;
3630 j->OutPt1 = op1;
3631 j->OutPt2 = op1b;
3632 return true;
3633 } else
3634 {
3635 op1b = DupOutPt(op1, true);
3636 op2b = DupOutPt(op2, false);
3637 op1->Next = op2;
3638 op2->Prev = op1;
3639 op1b->Prev = op2b;
3640 op2b->Next = op1b;
3641 j->OutPt1 = op1;
3642 j->OutPt2 = op1b;
3643 return true;
3644 }
3645 }
3646}
3647//----------------------------------------------------------------------
3648
3649static OutRec* ParseFirstLeft(OutRec* FirstLeft)
3650{
3651 while (FirstLeft && !FirstLeft->Pts)
3652 FirstLeft = FirstLeft->FirstLeft;
3653 return FirstLeft;
3654}
3655//------------------------------------------------------------------------------
3656
3657void Clipper::FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec)
3658{
3659 //tests if NewOutRec contains the polygon before reassigning FirstLeft
3660 for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
3661 {
3662 OutRec* outRec = m_PolyOuts[i];
3663 OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft);
3664 if (outRec->Pts && firstLeft == OldOutRec)
3665 {
3666 if (Poly2ContainsPoly1(outRec->Pts, NewOutRec->Pts))
3667 outRec->FirstLeft = NewOutRec;
3668 }
3669 }
3670}
3671//----------------------------------------------------------------------
3672
3673void Clipper::FixupFirstLefts2(OutRec* InnerOutRec, OutRec* OuterOutRec)
3674{
3675 //A polygon has split into two such that one is now the inner of the other.
3676 //It's possible that these polygons now wrap around other polygons, so check
3677 //every polygon that's also contained by OuterOutRec's FirstLeft container
3678 //(including 0) to see if they've become inner to the new inner polygon ...
3679 OutRec* orfl = OuterOutRec->FirstLeft;
3680 for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
3681 {
3682 OutRec* outRec = m_PolyOuts[i];
3683
3684 if (!outRec->Pts || outRec == OuterOutRec || outRec == InnerOutRec)
3685 continue;
3686 OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft);
3687 if (firstLeft != orfl && firstLeft != InnerOutRec && firstLeft != OuterOutRec)
3688 continue;
3689 if (Poly2ContainsPoly1(outRec->Pts, InnerOutRec->Pts))
3690 outRec->FirstLeft = InnerOutRec;
3691 else if (Poly2ContainsPoly1(outRec->Pts, OuterOutRec->Pts))
3692 outRec->FirstLeft = OuterOutRec;
3693 else if (outRec->FirstLeft == InnerOutRec || outRec->FirstLeft == OuterOutRec)
3694 outRec->FirstLeft = orfl;
3695 }
3696}
3697//----------------------------------------------------------------------
3698void Clipper::FixupFirstLefts3(OutRec* OldOutRec, OutRec* NewOutRec)
3699{
3700 //reassigns FirstLeft WITHOUT testing if NewOutRec contains the polygon
3701 for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
3702 {
3703 OutRec* outRec = m_PolyOuts[i];
3704 OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft);
3705 if (outRec->Pts && firstLeft == OldOutRec)
3706 outRec->FirstLeft = NewOutRec;
3707 }
3708}
3709//----------------------------------------------------------------------
3710
3711void Clipper::JoinCommonEdges()
3712{
3713 for (JoinList::size_type i = 0; i < m_Joins.size(); i++)
3714 {
3715 Join* join = m_Joins[i];
3716
3717 OutRec *outRec1 = GetOutRec(join->OutPt1->Idx);
3718 OutRec *outRec2 = GetOutRec(join->OutPt2->Idx);
3719
3720 if (!outRec1->Pts || !outRec2->Pts) continue;
3721 if (outRec1->IsOpen || outRec2->IsOpen) continue;
3722
3723 //get the polygon fragment with the correct hole state (FirstLeft)
3724 //before calling JoinPoints() ...
3725 OutRec *holeStateRec;
3726 if (outRec1 == outRec2) holeStateRec = outRec1;
3727 else if (OutRec1RightOfOutRec2(outRec1, outRec2)) holeStateRec = outRec2;
3728 else if (OutRec1RightOfOutRec2(outRec2, outRec1)) holeStateRec = outRec1;
3729 else holeStateRec = GetLowermostRec(outRec1, outRec2);
3730
3731 if (!JoinPoints(join, outRec1, outRec2)) continue;
3732
3733 if (outRec1 == outRec2)
3734 {
3735 //instead of joining two polygons, we've just created a new one by
3736 //splitting one polygon into two.
3737 outRec1->Pts = join->OutPt1;
3738 outRec1->BottomPt = 0;
3739 outRec2 = CreateOutRec();
3740 outRec2->Pts = join->OutPt2;
3741
3742 //update all OutRec2.Pts Idx's ...
3743 UpdateOutPtIdxs(*outRec2);
3744
3745 if (Poly2ContainsPoly1(outRec2->Pts, outRec1->Pts))
3746 {
3747 //outRec1 contains outRec2 ...
3748 outRec2->IsHole = !outRec1->IsHole;
3749 outRec2->FirstLeft = outRec1;
3750
3751 if (m_UsingPolyTree) FixupFirstLefts2(outRec2, outRec1);
3752
3753 if ((outRec2->IsHole ^ m_ReverseOutput) == (Area(*outRec2) > 0))
3754 ReversePolyPtLinks(outRec2->Pts);
3755
3756 } else if (Poly2ContainsPoly1(outRec1->Pts, outRec2->Pts))
3757 {
3758 //outRec2 contains outRec1 ...
3759 outRec2->IsHole = outRec1->IsHole;
3760 outRec1->IsHole = !outRec2->IsHole;
3761 outRec2->FirstLeft = outRec1->FirstLeft;
3762 outRec1->FirstLeft = outRec2;
3763
3764 if (m_UsingPolyTree) FixupFirstLefts2(outRec1, outRec2);
3765
3766 if ((outRec1->IsHole ^ m_ReverseOutput) == (Area(*outRec1) > 0))
3767 ReversePolyPtLinks(outRec1->Pts);
3768 }
3769 else
3770 {
3771 //the 2 polygons are completely separate ...
3772 outRec2->IsHole = outRec1->IsHole;
3773 outRec2->FirstLeft = outRec1->FirstLeft;
3774
3775 //fixup FirstLeft pointers that may need reassigning to OutRec2
3776 if (m_UsingPolyTree) FixupFirstLefts1(outRec1, outRec2);
3777 }
3778
3779 } else
3780 {
3781 //joined 2 polygons together ...
3782
3783 outRec2->Pts = 0;
3784 outRec2->BottomPt = 0;
3785 outRec2->Idx = outRec1->Idx;
3786
3787 outRec1->IsHole = holeStateRec->IsHole;
3788 if (holeStateRec == outRec2)
3789 outRec1->FirstLeft = outRec2->FirstLeft;
3790 outRec2->FirstLeft = outRec1;
3791
3792 if (m_UsingPolyTree) FixupFirstLefts3(outRec2, outRec1);
3793 }
3794 }
3795}
3796
3797//------------------------------------------------------------------------------
3798// ClipperOffset support functions ...
3799//------------------------------------------------------------------------------
3800
3801DoublePoint GetUnitNormal(const IntPoint &pt1, const IntPoint &pt2)
3802{
3803 if(pt2.X == pt1.X && pt2.Y == pt1.Y)
3804 return DoublePoint(0, 0);
3805
3806 double Dx = (double)(pt2.X - pt1.X);
3807 double dy = (double)(pt2.Y - pt1.Y);
3808 double f = 1 *1.0/ std::sqrt( Dx*Dx + dy*dy );
3809 Dx *= f;
3810 dy *= f;
3811 return DoublePoint(dy, -Dx);
3812}
3813
3814//------------------------------------------------------------------------------
3815// ClipperOffset class
3816//------------------------------------------------------------------------------
3817
3818ClipperOffset::ClipperOffset(double miterLimit, double arcTolerance)
3819{
3820 this->MiterLimit = miterLimit;
3821 this->ArcTolerance = arcTolerance;
3822 m_lowest.X = -1;
3823}
3824//------------------------------------------------------------------------------
3825
3826ClipperOffset::~ClipperOffset()
3827{
3828 Clear();
3829}
3830//------------------------------------------------------------------------------
3831
3832void ClipperOffset::Clear()
3833{
3834 for (int i = 0; i < m_polyNodes.ChildCount(); ++i)
3835 delete m_polyNodes.Childs[i];
3836 m_polyNodes.Childs.clear();
3837 m_lowest.X = -1;
3838}
3839//------------------------------------------------------------------------------
3840
3841void ClipperOffset::AddPath(const Path& path, JoinType joinType, EndType endType)
3842{
3843 int highI = (int)path.size() - 1;
3844 if (highI < 0) return;
3845 PolyNode* newNode = new PolyNode();
3846 newNode->m_jointype = joinType;
3847 newNode->m_endtype = endType;
3848
3849 //strip duplicate points from path and also get index to the lowest point ...
3850 if (endType == etClosedLine || endType == etClosedPolygon)
3851 while (highI > 0 && path[0] == path[highI]) highI--;
3852 newNode->Contour.reserve(highI + 1);
3853 newNode->Contour.push_back(path[0]);
3854 int j = 0, k = 0;
3855 for (int i = 1; i <= highI; i++)
3856 if (newNode->Contour[j] != path[i])
3857 {
3858 j++;
3859 newNode->Contour.push_back(path[i]);
3860 if (path[i].Y > newNode->Contour[k].Y ||
3861 (path[i].Y == newNode->Contour[k].Y &&
3862 path[i].X < newNode->Contour[k].X)) k = j;
3863 }
3864 if (endType == etClosedPolygon && j < 2)
3865 {
3866 delete newNode;
3867 return;
3868 }
3869 m_polyNodes.AddChild(*newNode);
3870
3871 //if this path's lowest pt is lower than all the others then update m_lowest
3872 if (endType != etClosedPolygon) return;
3873 if (m_lowest.X < 0)
3874 m_lowest = IntPoint(m_polyNodes.ChildCount() - 1, k);
3875 else
3876 {
3877 IntPoint ip = m_polyNodes.Childs[(int)m_lowest.X]->Contour[(int)m_lowest.Y];
3878 if (newNode->Contour[k].Y > ip.Y ||
3879 (newNode->Contour[k].Y == ip.Y &&
3880 newNode->Contour[k].X < ip.X))
3881 m_lowest = IntPoint(m_polyNodes.ChildCount() - 1, k);
3882 }
3883}
3884//------------------------------------------------------------------------------
3885
3886void ClipperOffset::AddPaths(const Paths& paths, JoinType joinType, EndType endType)
3887{
3888 for (Paths::size_type i = 0; i < paths.size(); ++i)
3889 AddPath(paths[i], joinType, endType);
3890}
3891//------------------------------------------------------------------------------
3892
3893void ClipperOffset::FixOrientations()
3894{
3895 //fixup orientations of all closed paths if the orientation of the
3896 //closed path with the lowermost vertex is wrong ...
3897 if (m_lowest.X >= 0 &&
3898 !Orientation(m_polyNodes.Childs[(int)m_lowest.X]->Contour))
3899 {
3900 for (int i = 0; i < m_polyNodes.ChildCount(); ++i)
3901 {
3902 PolyNode& node = *m_polyNodes.Childs[i];
3903 if (node.m_endtype == etClosedPolygon ||
3904 (node.m_endtype == etClosedLine && Orientation(node.Contour)))
3905 ReversePath(node.Contour);
3906 }
3907 } else
3908 {
3909 for (int i = 0; i < m_polyNodes.ChildCount(); ++i)
3910 {
3911 PolyNode& node = *m_polyNodes.Childs[i];
3912 if (node.m_endtype == etClosedLine && !Orientation(node.Contour))
3913 ReversePath(node.Contour);
3914 }
3915 }
3916}
3917//------------------------------------------------------------------------------
3918
3919void ClipperOffset::Execute(Paths& solution, double delta)
3920{
3921 solution.clear();
3922 FixOrientations();
3923 DoOffset(delta);
3924
3925 //now clean up 'corners' ...
3926 Clipper clpr;
3927 clpr.AddPaths(m_destPolys, ptSubject, true);
3928 if (delta > 0)
3929 {
3930 clpr.Execute(ctUnion, solution, pftPositive, pftPositive);
3931 }
3932 else
3933 {
3934 IntRect r = clpr.GetBounds();
3935 Path outer(4);
3936 outer[0] = IntPoint(r.left - 10, r.bottom + 10);
3937 outer[1] = IntPoint(r.right + 10, r.bottom + 10);
3938 outer[2] = IntPoint(r.right + 10, r.top - 10);
3939 outer[3] = IntPoint(r.left - 10, r.top - 10);
3940
3941 clpr.AddPath(outer, ptSubject, true);
3942 clpr.ReverseSolution(true);
3943 clpr.Execute(ctUnion, solution, pftNegative, pftNegative);
3944 if (solution.size() > 0) solution.erase(solution.begin());
3945 }
3946}
3947//------------------------------------------------------------------------------
3948
3949void ClipperOffset::Execute(PolyTree& solution, double delta)
3950{
3951 solution.Clear();
3952 FixOrientations();
3953 DoOffset(delta);
3954
3955 //now clean up 'corners' ...
3956 Clipper clpr;
3957 clpr.AddPaths(m_destPolys, ptSubject, true);
3958 if (delta > 0)
3959 {
3960 clpr.Execute(ctUnion, solution, pftPositive, pftPositive);
3961 }
3962 else
3963 {
3964 IntRect r = clpr.GetBounds();
3965 Path outer(4);
3966 outer[0] = IntPoint(r.left - 10, r.bottom + 10);
3967 outer[1] = IntPoint(r.right + 10, r.bottom + 10);
3968 outer[2] = IntPoint(r.right + 10, r.top - 10);
3969 outer[3] = IntPoint(r.left - 10, r.top - 10);
3970
3971 clpr.AddPath(outer, ptSubject, true);
3972 clpr.ReverseSolution(true);
3973 clpr.Execute(ctUnion, solution, pftNegative, pftNegative);
3974 //remove the outer PolyNode rectangle ...
3975 if (solution.ChildCount() == 1 && solution.Childs[0]->ChildCount() > 0)
3976 {
3977 PolyNode* outerNode = solution.Childs[0];
3978 solution.Childs.reserve(outerNode->ChildCount());
3979 solution.Childs[0] = outerNode->Childs[0];
3980 solution.Childs[0]->Parent = outerNode->Parent;
3981 for (int i = 1; i < outerNode->ChildCount(); ++i)
3982 solution.AddChild(*outerNode->Childs[i]);
3983 }
3984 else
3985 solution.Clear();
3986 }
3987}
3988//------------------------------------------------------------------------------
3989
3990void ClipperOffset::DoOffset(double delta)
3991{
3992 m_destPolys.clear();
3993 m_delta = delta;
3994
3995 //if Zero offset, just copy any CLOSED polygons to m_p and return ...
3996 if (NEAR_ZERO(delta))
3997 {
3998 m_destPolys.reserve(m_polyNodes.ChildCount());
3999 for (int i = 0; i < m_polyNodes.ChildCount(); i++)
4000 {
4001 PolyNode& node = *m_polyNodes.Childs[i];
4002 if (node.m_endtype == etClosedPolygon)
4003 m_destPolys.push_back(node.Contour);
4004 }
4005 return;
4006 }
4007
4008 //see offset_triginometry3.svg in the documentation folder ...
4009 if (MiterLimit > 2) m_miterLim = 2/(MiterLimit * MiterLimit);
4010 else m_miterLim = 0.5;
4011
4012 double y;
4013 if (ArcTolerance <= 0.0) y = def_arc_tolerance;
4014 else if (ArcTolerance > std::fabs(delta) * def_arc_tolerance)
4015 y = std::fabs(delta) * def_arc_tolerance;
4016 else y = ArcTolerance;
4017 //see offset_triginometry2.svg in the documentation folder ...
4018 double steps = pi / std::acos(1 - y / std::fabs(delta));
4019 if (steps > std::fabs(delta) * pi)
4020 steps = std::fabs(delta) * pi; //ie excessive precision check
4021 m_sin = std::sin(two_pi / steps);
4022 m_cos = std::cos(two_pi / steps);
4023 m_StepsPerRad = steps / two_pi;
4024 if (delta < 0.0) m_sin = -m_sin;
4025
4026 m_destPolys.reserve(m_polyNodes.ChildCount() * 2);
4027 for (int i = 0; i < m_polyNodes.ChildCount(); i++)
4028 {
4029 PolyNode& node = *m_polyNodes.Childs[i];
4030 m_srcPoly = node.Contour;
4031
4032 int len = (int)m_srcPoly.size();
4033 if (len == 0 || (delta <= 0 && (len < 3 || node.m_endtype != etClosedPolygon)))
4034 continue;
4035
4036 m_destPoly.clear();
4037 if (len == 1)
4038 {
4039 if (node.m_jointype == jtRound)
4040 {
4041 double X = 1.0, Y = 0.0;
4042 for (cInt j = 1; j <= steps; j++)
4043 {
4044 m_destPoly.push_back(IntPoint(
4045 Round(m_srcPoly[0].X + X * delta),
4046 Round(m_srcPoly[0].Y + Y * delta)));
4047 double X2 = X;
4048 X = X * m_cos - m_sin * Y;
4049 Y = X2 * m_sin + Y * m_cos;
4050 }
4051 }
4052 else
4053 {
4054 double X = -1.0, Y = -1.0;
4055 for (int j = 0; j < 4; ++j)
4056 {
4057 m_destPoly.push_back(IntPoint(
4058 Round(m_srcPoly[0].X + X * delta),
4059 Round(m_srcPoly[0].Y + Y * delta)));
4060 if (X < 0) X = 1;
4061 else if (Y < 0) Y = 1;
4062 else X = -1;
4063 }
4064 }
4065 m_destPolys.push_back(m_destPoly);
4066 continue;
4067 }
4068 //build m_normals ...
4069 m_normals.clear();
4070 m_normals.reserve(len);
4071 for (int j = 0; j < len - 1; ++j)
4072 m_normals.push_back(GetUnitNormal(m_srcPoly[j], m_srcPoly[j + 1]));
4073 if (node.m_endtype == etClosedLine || node.m_endtype == etClosedPolygon)
4074 m_normals.push_back(GetUnitNormal(m_srcPoly[len - 1], m_srcPoly[0]));
4075 else
4076 m_normals.push_back(DoublePoint(m_normals[len - 2]));
4077
4078 if (node.m_endtype == etClosedPolygon)
4079 {
4080 int k = len - 1;
4081 for (int j = 0; j < len; ++j)
4082 OffsetPoint(j, k, node.m_jointype);
4083 m_destPolys.push_back(m_destPoly);
4084 }
4085 else if (node.m_endtype == etClosedLine)
4086 {
4087 int k = len - 1;
4088 for (int j = 0; j < len; ++j)
4089 OffsetPoint(j, k, node.m_jointype);
4090 m_destPolys.push_back(m_destPoly);
4091 m_destPoly.clear();
4092 //re-build m_normals ...
4093 DoublePoint n = m_normals[len -1];
4094 for (int j = len - 1; j > 0; j--)
4095 m_normals[j] = DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y);
4096 m_normals[0] = DoublePoint(-n.X, -n.Y);
4097 k = 0;
4098 for (int j = len - 1; j >= 0; j--)
4099 OffsetPoint(j, k, node.m_jointype);
4100 m_destPolys.push_back(m_destPoly);
4101 }
4102 else
4103 {
4104 int k = 0;
4105 for (int j = 1; j < len - 1; ++j)
4106 OffsetPoint(j, k, node.m_jointype);
4107
4108 IntPoint pt1;
4109 if (node.m_endtype == etOpenButt)
4110 {
4111 int j = len - 1;
4112 pt1 = IntPoint((cInt)Round(m_srcPoly[j].X + m_normals[j].X *
4113 delta), (cInt)Round(m_srcPoly[j].Y + m_normals[j].Y * delta));
4114 m_destPoly.push_back(pt1);
4115 pt1 = IntPoint((cInt)Round(m_srcPoly[j].X - m_normals[j].X *
4116 delta), (cInt)Round(m_srcPoly[j].Y - m_normals[j].Y * delta));
4117 m_destPoly.push_back(pt1);
4118 }
4119 else
4120 {
4121 int j = len - 1;
4122 k = len - 2;
4123 m_sinA = 0;
4124 m_normals[j] = DoublePoint(-m_normals[j].X, -m_normals[j].Y);
4125 if (node.m_endtype == etOpenSquare)
4126 DoSquare(j, k);
4127 else
4128 DoRound(j, k);
4129 }
4130
4131 //re-build m_normals ...
4132 for (int j = len - 1; j > 0; j--)
4133 m_normals[j] = DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y);
4134 m_normals[0] = DoublePoint(-m_normals[1].X, -m_normals[1].Y);
4135
4136 k = len - 1;
4137 for (int j = k - 1; j > 0; --j) OffsetPoint(j, k, node.m_jointype);
4138
4139 if (node.m_endtype == etOpenButt)
4140 {
4141 pt1 = IntPoint((cInt)Round(m_srcPoly[0].X - m_normals[0].X * delta),
4142 (cInt)Round(m_srcPoly[0].Y - m_normals[0].Y * delta));
4143 m_destPoly.push_back(pt1);
4144 pt1 = IntPoint((cInt)Round(m_srcPoly[0].X + m_normals[0].X * delta),
4145 (cInt)Round(m_srcPoly[0].Y + m_normals[0].Y * delta));
4146 m_destPoly.push_back(pt1);
4147 }
4148 else
4149 {
4150 k = 1;
4151 m_sinA = 0;
4152 if (node.m_endtype == etOpenSquare)
4153 DoSquare(0, 1);
4154 else
4155 DoRound(0, 1);
4156 }
4157 m_destPolys.push_back(m_destPoly);
4158 }
4159 }
4160}
4161//------------------------------------------------------------------------------
4162
4163void ClipperOffset::OffsetPoint(int j, int& k, JoinType jointype)
4164{
4165 //cross product ...
4166 m_sinA = (m_normals[k].X * m_normals[j].Y - m_normals[j].X * m_normals[k].Y);
4167 if (std::fabs(m_sinA * m_delta) < 1.0)
4168 {
4169 //dot product ...
4170 double cosA = (m_normals[k].X * m_normals[j].X + m_normals[j].Y * m_normals[k].Y );
4171 if (cosA > 0) // angle => 0 degrees
4172 {
4173 m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
4174 Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta)));
4175 return;
4176 }
4177 //else angle => 180 degrees
4178 }
4179 else if (m_sinA > 1.0) m_sinA = 1.0;
4180 else if (m_sinA < -1.0) m_sinA = -1.0;
4181
4182 if (m_sinA * m_delta < 0)
4183 {
4184 m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
4185 Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta)));
4186 m_destPoly.push_back(m_srcPoly[j]);
4187 m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
4188 Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta)));
4189 }
4190 else
4191 switch (jointype)
4192 {
4193 case jtMiter:
4194 {
4195 double r = 1 + (m_normals[j].X * m_normals[k].X +
4196 m_normals[j].Y * m_normals[k].Y);
4197 if (r >= m_miterLim) DoMiter(j, k, r); else DoSquare(j, k);
4198 break;
4199 }
4200 case jtSquare: DoSquare(j, k); break;
4201 case jtRound: DoRound(j, k); break;
4202 }
4203 k = j;
4204}
4205//------------------------------------------------------------------------------
4206
4207void ClipperOffset::DoSquare(int j, int k)
4208{
4209 double dx = std::tan(std::atan2(m_sinA,
4210 m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y) / 4);
4211 m_destPoly.push_back(IntPoint(
4212 Round(m_srcPoly[j].X + m_delta * (m_normals[k].X - m_normals[k].Y * dx)),
4213 Round(m_srcPoly[j].Y + m_delta * (m_normals[k].Y + m_normals[k].X * dx))));
4214 m_destPoly.push_back(IntPoint(
4215 Round(m_srcPoly[j].X + m_delta * (m_normals[j].X + m_normals[j].Y * dx)),
4216 Round(m_srcPoly[j].Y + m_delta * (m_normals[j].Y - m_normals[j].X * dx))));
4217}
4218//------------------------------------------------------------------------------
4219
4220void ClipperOffset::DoMiter(int j, int k, double r)
4221{
4222 double q = m_delta / r;
4223 m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + (m_normals[k].X + m_normals[j].X) * q),
4224 Round(m_srcPoly[j].Y + (m_normals[k].Y + m_normals[j].Y) * q)));
4225}
4226//------------------------------------------------------------------------------
4227
4228void ClipperOffset::DoRound(int j, int k)
4229{
4230 double a = std::atan2(m_sinA,
4231 m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y);
4232 int steps = std::max((int)Round(m_StepsPerRad * std::fabs(a)), 1);
4233
4234 double X = m_normals[k].X, Y = m_normals[k].Y, X2;
4235 for (int i = 0; i < steps; ++i)
4236 {
4237 m_destPoly.push_back(IntPoint(
4238 Round(m_srcPoly[j].X + X * m_delta),
4239 Round(m_srcPoly[j].Y + Y * m_delta)));
4240 X2 = X;
4241 X = X * m_cos - m_sin * Y;
4242 Y = X2 * m_sin + Y * m_cos;
4243 }
4244 m_destPoly.push_back(IntPoint(
4245 Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
4246 Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta)));
4247}
4248
4249//------------------------------------------------------------------------------
4250// Miscellaneous public functions
4251//------------------------------------------------------------------------------
4252
4253void Clipper::DoSimplePolygons()
4254{
4255 PolyOutList::size_type i = 0;
4256 while (i < m_PolyOuts.size())
4257 {
4258 OutRec* outrec = m_PolyOuts[i++];
4259 OutPt* op = outrec->Pts;
4260 if (!op || outrec->IsOpen) continue;
4261 do //for each Pt in Polygon until duplicate found do ...
4262 {
4263 OutPt* op2 = op->Next;
4264 while (op2 != outrec->Pts)
4265 {
4266 if ((op->Pt == op2->Pt) && op2->Next != op && op2->Prev != op)
4267 {
4268 //split the polygon into two ...
4269 OutPt* op3 = op->Prev;
4270 OutPt* op4 = op2->Prev;
4271 op->Prev = op4;
4272 op4->Next = op;
4273 op2->Prev = op3;
4274 op3->Next = op2;
4275
4276 outrec->Pts = op;
4277 OutRec* outrec2 = CreateOutRec();
4278 outrec2->Pts = op2;
4279 UpdateOutPtIdxs(*outrec2);
4280 if (Poly2ContainsPoly1(outrec2->Pts, outrec->Pts))
4281 {
4282 //OutRec2 is contained by OutRec1 ...
4283 outrec2->IsHole = !outrec->IsHole;
4284 outrec2->FirstLeft = outrec;
4285 if (m_UsingPolyTree) FixupFirstLefts2(outrec2, outrec);
4286 }
4287 else
4288 if (Poly2ContainsPoly1(outrec->Pts, outrec2->Pts))
4289 {
4290 //OutRec1 is contained by OutRec2 ...
4291 outrec2->IsHole = outrec->IsHole;
4292 outrec->IsHole = !outrec2->IsHole;
4293 outrec2->FirstLeft = outrec->FirstLeft;
4294 outrec->FirstLeft = outrec2;
4295 if (m_UsingPolyTree) FixupFirstLefts2(outrec, outrec2);
4296 }
4297 else
4298 {
4299 //the 2 polygons are separate ...
4300 outrec2->IsHole = outrec->IsHole;
4301 outrec2->FirstLeft = outrec->FirstLeft;
4302 if (m_UsingPolyTree) FixupFirstLefts1(outrec, outrec2);
4303 }
4304 op2 = op; //ie get ready for the Next iteration
4305 }
4306 op2 = op2->Next;
4307 }
4308 op = op->Next;
4309 }
4310 while (op != outrec->Pts);
4311 }
4312}
4313//------------------------------------------------------------------------------
4314
4315void ReversePath(Path& p)
4316{
4317 std::reverse(p.begin(), p.end());
4318}
4319//------------------------------------------------------------------------------
4320
4321void ReversePaths(Paths& p)
4322{
4323 for (Paths::size_type i = 0; i < p.size(); ++i)
4324 ReversePath(p[i]);
4325}
4326//------------------------------------------------------------------------------
4327
4328void SimplifyPolygon(const Path &in_poly, Paths &out_polys, PolyFillType fillType)
4329{
4330 Clipper c;
4331 c.StrictlySimple(true);
4332 c.AddPath(in_poly, ptSubject, true);
4333 c.Execute(ctUnion, out_polys, fillType, fillType);
4334}
4335//------------------------------------------------------------------------------
4336
4337void SimplifyPolygons(const Paths &in_polys, Paths &out_polys, PolyFillType fillType)
4338{
4339 Clipper c;
4340 c.StrictlySimple(true);
4341 c.AddPaths(in_polys, ptSubject, true);
4342 c.Execute(ctUnion, out_polys, fillType, fillType);
4343}
4344//------------------------------------------------------------------------------
4345
4346void SimplifyPolygons(Paths &polys, PolyFillType fillType)
4347{
4348 SimplifyPolygons(polys, polys, fillType);
4349}
4350//------------------------------------------------------------------------------
4351
4352inline double DistanceSqrd(const IntPoint& pt1, const IntPoint& pt2)
4353{
4354 double Dx = ((double)pt1.X - pt2.X);
4355 double dy = ((double)pt1.Y - pt2.Y);
4356 return (Dx*Dx + dy*dy);
4357}
4358//------------------------------------------------------------------------------
4359
4360double DistanceFromLineSqrd(
4361 const IntPoint& pt, const IntPoint& ln1, const IntPoint& ln2)
4362{
4363 //The equation of a line in general form (Ax + By + C = 0)
4364 //given 2 points (x¹,y¹) & (x²,y²) is ...
4365 //(y¹ - y²)x + (x² - x¹)y + (y² - y¹)x¹ - (x² - x¹)y¹ = 0
4366 //A = (y¹ - y²); B = (x² - x¹); C = (y² - y¹)x¹ - (x² - x¹)y¹
4367 //perpendicular distance of point (x³,y³) = (Ax³ + By³ + C)/Sqrt(A² + B²)
4368 //see http://en.wikipedia.org/wiki/Perpendicular_distance
4369 double A = double(ln1.Y - ln2.Y);
4370 double B = double(ln2.X - ln1.X);
4371 double C = A * ln1.X + B * ln1.Y;
4372 C = A * pt.X + B * pt.Y - C;
4373 return (C * C) / (A * A + B * B);
4374}
4375//---------------------------------------------------------------------------
4376
4377bool SlopesNearCollinear(const IntPoint& pt1,
4378 const IntPoint& pt2, const IntPoint& pt3, double distSqrd)
4379{
4380 //this function is more accurate when the point that's geometrically
4381 //between the other 2 points is the one that's tested for distance.
4382 //ie makes it more likely to pick up 'spikes' ...
4383 if (Abs(pt1.X - pt2.X) > Abs(pt1.Y - pt2.Y))
4384 {
4385 if ((pt1.X > pt2.X) == (pt1.X < pt3.X))
4386 return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
4387 else if ((pt2.X > pt1.X) == (pt2.X < pt3.X))
4388 return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
4389 else
4390 return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
4391 }
4392 else
4393 {
4394 if ((pt1.Y > pt2.Y) == (pt1.Y < pt3.Y))
4395 return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
4396 else if ((pt2.Y > pt1.Y) == (pt2.Y < pt3.Y))
4397 return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
4398 else
4399 return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
4400 }
4401}
4402//------------------------------------------------------------------------------
4403
4404bool PointsAreClose(IntPoint pt1, IntPoint pt2, double distSqrd)
4405{
4406 double Dx = (double)pt1.X - pt2.X;
4407 double dy = (double)pt1.Y - pt2.Y;
4408 return ((Dx * Dx) + (dy * dy) <= distSqrd);
4409}
4410//------------------------------------------------------------------------------
4411
4412OutPt* ExcludeOp(OutPt* op)
4413{
4414 OutPt* result = op->Prev;
4415 result->Next = op->Next;
4416 op->Next->Prev = result;
4417 result->Idx = 0;
4418 return result;
4419}
4420//------------------------------------------------------------------------------
4421
4422void CleanPolygon(const Path& in_poly, Path& out_poly, double distance)
4423{
4424 //distance = proximity in units/pixels below which vertices
4425 //will be stripped. Default ~= sqrt(2).
4426
4427 size_t size = in_poly.size();
4428
4429 if (size == 0)
4430 {
4431 out_poly.clear();
4432 return;
4433 }
4434
4435 OutPt* outPts = new OutPt[size];
4436 for (size_t i = 0; i < size; ++i)
4437 {
4438 outPts[i].Pt = in_poly[i];
4439 outPts[i].Next = &outPts[(i + 1) % size];
4440 outPts[i].Next->Prev = &outPts[i];
4441 outPts[i].Idx = 0;
4442 }
4443
4444 double distSqrd = distance * distance;
4445 OutPt* op = &outPts[0];
4446 while (op->Idx == 0 && op->Next != op->Prev)
4447 {
4448 if (PointsAreClose(op->Pt, op->Prev->Pt, distSqrd))
4449 {
4450 op = ExcludeOp(op);
4451 size--;
4452 }
4453 else if (PointsAreClose(op->Prev->Pt, op->Next->Pt, distSqrd))
4454 {
4455 ExcludeOp(op->Next);
4456 op = ExcludeOp(op);
4457 size -= 2;
4458 }
4459 else if (SlopesNearCollinear(op->Prev->Pt, op->Pt, op->Next->Pt, distSqrd))
4460 {
4461 op = ExcludeOp(op);
4462 size--;
4463 }
4464 else
4465 {
4466 op->Idx = 1;
4467 op = op->Next;
4468 }
4469 }
4470
4471 if (size < 3) size = 0;
4472 out_poly.resize(size);
4473 for (size_t i = 0; i < size; ++i)
4474 {
4475 out_poly[i] = op->Pt;
4476 op = op->Next;
4477 }
4478 delete [] outPts;
4479}
4480//------------------------------------------------------------------------------
4481
4482void CleanPolygon(Path& poly, double distance)
4483{
4484 CleanPolygon(poly, poly, distance);
4485}
4486//------------------------------------------------------------------------------
4487
4488void CleanPolygons(const Paths& in_polys, Paths& out_polys, double distance)
4489{
4490 out_polys.resize(in_polys.size());
4491 for (Paths::size_type i = 0; i < in_polys.size(); ++i)
4492 CleanPolygon(in_polys[i], out_polys[i], distance);
4493}
4494//------------------------------------------------------------------------------
4495
4496void CleanPolygons(Paths& polys, double distance)
4497{
4498 CleanPolygons(polys, polys, distance);
4499}
4500//------------------------------------------------------------------------------
4501
4502void Minkowski(const Path& poly, const Path& path,
4503 Paths& solution, bool isSum, bool isClosed)
4504{
4505 int delta = (isClosed ? 1 : 0);
4506 size_t polyCnt = poly.size();
4507 size_t pathCnt = path.size();
4508 Paths pp;
4509 pp.reserve(pathCnt);
4510 if (isSum)
4511 for (size_t i = 0; i < pathCnt; ++i)
4512 {
4513 Path p;
4514 p.reserve(polyCnt);
4515 for (size_t j = 0; j < poly.size(); ++j)
4516 p.push_back(IntPoint(path[i].X + poly[j].X, path[i].Y + poly[j].Y));
4517 pp.push_back(p);
4518 }
4519 else
4520 for (size_t i = 0; i < pathCnt; ++i)
4521 {
4522 Path p;
4523 p.reserve(polyCnt);
4524 for (size_t j = 0; j < poly.size(); ++j)
4525 p.push_back(IntPoint(path[i].X - poly[j].X, path[i].Y - poly[j].Y));
4526 pp.push_back(p);
4527 }
4528
4529 solution.clear();
4530 solution.reserve((pathCnt + delta) * (polyCnt + 1));
4531 for (size_t i = 0; i < pathCnt - 1 + delta; ++i)
4532 for (size_t j = 0; j < polyCnt; ++j)
4533 {
4534 Path quad;
4535 quad.reserve(4);
4536 quad.push_back(pp[i % pathCnt][j % polyCnt]);
4537 quad.push_back(pp[(i + 1) % pathCnt][j % polyCnt]);
4538 quad.push_back(pp[(i + 1) % pathCnt][(j + 1) % polyCnt]);
4539 quad.push_back(pp[i % pathCnt][(j + 1) % polyCnt]);
4540 if (!Orientation(quad)) ReversePath(quad);
4541 solution.push_back(quad);
4542 }
4543}
4544//------------------------------------------------------------------------------
4545
4546void MinkowskiSum(const Path& pattern, const Path& path, Paths& solution, bool pathIsClosed)
4547{
4548 Minkowski(pattern, path, solution, true, pathIsClosed);
4549 Clipper c;
4550 c.AddPaths(solution, ptSubject, true);
4551 c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
4552}
4553//------------------------------------------------------------------------------
4554
4555void TranslatePath(const Path& input, Path& output, const IntPoint delta)
4556{
4557 //precondition: input != output
4558 output.resize(input.size());
4559 for (size_t i = 0; i < input.size(); ++i)
4560 output[i] = IntPoint(input[i].X + delta.X, input[i].Y + delta.Y);
4561}
4562//------------------------------------------------------------------------------
4563
4564void MinkowskiSum(const Path& pattern, const Paths& paths, Paths& solution, bool pathIsClosed)
4565{
4566 Clipper c;
4567 for (size_t i = 0; i < paths.size(); ++i)
4568 {
4569 Paths tmp;
4570 Minkowski(pattern, paths[i], tmp, true, pathIsClosed);
4571 c.AddPaths(tmp, ptSubject, true);
4572 if (pathIsClosed)
4573 {
4574 Path tmp2;
4575 TranslatePath(paths[i], tmp2, pattern[0]);
4576 c.AddPath(tmp2, ptClip, true);
4577 }
4578 }
4579 c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
4580}
4581//------------------------------------------------------------------------------
4582
4583void MinkowskiDiff(const Path& poly1, const Path& poly2, Paths& solution)
4584{
4585 Minkowski(poly1, poly2, solution, false, true);
4586 Clipper c;
4587 c.AddPaths(solution, ptSubject, true);
4588 c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
4589}
4590//------------------------------------------------------------------------------
4591
4592enum NodeType {ntAny, ntOpen, ntClosed};
4593
4594void AddPolyNodeToPaths(const PolyNode& polynode, NodeType nodetype, Paths& paths)
4595{
4596 bool match = true;
4597 if (nodetype == ntClosed) match = !polynode.IsOpen();
4598 else if (nodetype == ntOpen) return;
4599
4600 if (!polynode.Contour.empty() && match)
4601 paths.push_back(polynode.Contour);
4602 for (int i = 0; i < polynode.ChildCount(); ++i)
4603 AddPolyNodeToPaths(*polynode.Childs[i], nodetype, paths);
4604}
4605//------------------------------------------------------------------------------
4606
4607void PolyTreeToPaths(const PolyTree& polytree, Paths& paths)
4608{
4609 paths.resize(0);
4610 paths.reserve(polytree.Total());
4611 AddPolyNodeToPaths(polytree, ntAny, paths);
4612}
4613//------------------------------------------------------------------------------
4614
4615void ClosedPathsFromPolyTree(const PolyTree& polytree, Paths& paths)
4616{
4617 paths.resize(0);
4618 paths.reserve(polytree.Total());
4619 AddPolyNodeToPaths(polytree, ntClosed, paths);
4620}
4621//------------------------------------------------------------------------------
4622
4623void OpenPathsFromPolyTree(PolyTree& polytree, Paths& paths)
4624{
4625 paths.resize(0);
4626 paths.reserve(polytree.Total());
4627 //Open paths are top level only, so ...
4628 for (int i = 0; i < polytree.ChildCount(); ++i)
4629 if (polytree.Childs[i]->IsOpen())
4630 paths.push_back(polytree.Childs[i]->Contour);
4631}
4632//------------------------------------------------------------------------------
4633
4634std::ostream& operator <<(std::ostream &s, const IntPoint &p)
4635{
4636 s << "(" << p.X << "," << p.Y << ")";
4637 return s;
4638}
4639//------------------------------------------------------------------------------
4640
4641std::ostream& operator <<(std::ostream &s, const Path &p)
4642{
4643 if (p.empty()) return s;
4644 Path::size_type last = p.size() -1;
4645 for (Path::size_type i = 0; i < last; i++)
4646 s << "(" << p[i].X << "," << p[i].Y << "), ";
4647 s << "(" << p[last].X << "," << p[last].Y << ")\n";
4648 return s;
4649}
4650//------------------------------------------------------------------------------
4651
4652std::ostream& operator <<(std::ostream &s, const Paths &p)
4653{
4654 for (Paths::size_type i = 0; i < p.size(); i++)
4655 s << p[i];
4656 s << "\n";
4657 return s;
4658}
4659//------------------------------------------------------------------------------
4660
4661} //ClipperLib namespace
4662