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/******************************************************************************* * * * Author : Angus Johnson * * Version : 6.4.0 * * Date : 2 July 2015 * * Website : http://www.angusj.com * * Copyright : Angus Johnson 2010-2015 * * * * License: * * Use, modification & distribution is subject to Boost Software License Ver 1. * * http://www.boost.org/LICENSE_1_0.txt * * * * Attributions: * * The code in this library is an extension of Bala Vatti's clipping algorithm: * * "A generic solution to polygon clipping" * * Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63. * * http://portal.acm.org/citation.cfm?id=129906 * * * * Computer graphics and geometric modeling: implementation and algorithms * * By Max K. Agoston * * Springer; 1 edition (January 4, 2005) * * http://books.google.com/books?q=vatti+clipping+agoston * * * * See also: * * "Polygon Offsetting by Computing Winding Numbers" * * Paper no. DETC2005-85513 pp. 565-575 * * ASME 2005 International Design Engineering Technical Conferences * * and Computers and Information in Engineering Conference (IDETC/CIE2005) * * September 24-28, 2005 , Long Beach, California, USA * * http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf * * * *******************************************************************************/ /******************************************************************************* * * * This is a translation of the Delphi Clipper library and the naming style * * used has retained a Delphi flavour. * * * *******************************************************************************/ #include "clipper.hpp" #include <cmath> #include <vector> #include <algorithm> #include <stdexcept> #include <cstring> #include <cstdlib> #include <ostream> #include <functional> namespace ClipperLib { static double const pi = 3.141592653589793238; static double const two_pi = pi *2; static double const def_arc_tolerance = 0.25; enum Direction { dRightToLeft, dLeftToRight }; static int const Unassigned = -1; //edge not currently 'owning' a solution static int const Skip = -2; //edge that would otherwise close a path #define HORIZONTAL (-1.0E+40) #define TOLERANCE (1.0e-20) #define NEAR_ZERO(val) (((val) > -TOLERANCE) && ((val) < TOLERANCE)) struct TEdge { IntPoint Bot; IntPoint Curr; //current (updated for every new scanbeam) IntPoint Top; double Dx; PolyType PolyTyp; EdgeSide Side; //side only refers to current side of solution poly int WindDelta; //1 or -1 depending on winding direction int WindCnt; int WindCnt2; //winding count of the opposite polytype int OutIdx; TEdge *Next; TEdge *Prev; TEdge *NextInLML; TEdge *NextInAEL; TEdge *PrevInAEL; TEdge *NextInSEL; TEdge *PrevInSEL; }; struct IntersectNode { TEdge *Edge1; TEdge *Edge2; IntPoint Pt; }; struct LocalMinimum { cInt Y; TEdge *LeftBound; TEdge *RightBound; }; struct OutPt; //OutRec: contains a path in the clipping solution. Edges in the AEL will //carry a pointer to an OutRec when they are part of the clipping solution. struct OutRec { int Idx; bool IsHole; bool IsOpen; OutRec *FirstLeft; //see comments in clipper.pas PolyNode *PolyNd; OutPt *Pts; OutPt *BottomPt; }; struct OutPt { int Idx; IntPoint Pt; OutPt *Next; OutPt *Prev; }; struct Join { OutPt *OutPt1; OutPt *OutPt2; IntPoint OffPt; }; struct LocMinSorter { inline bool operator()(const LocalMinimum& locMin1, const LocalMinimum& locMin2) { return locMin2.Y < locMin1.Y; } }; //------------------------------------------------------------------------------ //------------------------------------------------------------------------------ inline cInt Round(double val) { if ((val < 0)) return static_cast<cInt>(val - 0.5); else return static_cast<cInt>(val + 0.5); } //------------------------------------------------------------------------------ inline cInt Abs(cInt val) { return val < 0 ? -val : val; } //------------------------------------------------------------------------------ // PolyTree methods ... //------------------------------------------------------------------------------ void PolyTree::Clear() { for (PolyNodes::size_type i = 0; i < AllNodes.size(); ++i) delete AllNodes[i]; AllNodes.resize(0); Childs.resize(0); } //------------------------------------------------------------------------------ PolyNode* PolyTree::GetFirst() const { if (!Childs.empty()) return Childs[0]; else return 0; } //------------------------------------------------------------------------------ int PolyTree::Total() const { int result = (int)AllNodes.size(); //with negative offsets, ignore the hidden outer polygon ... if (result > 0 && Childs[0] != AllNodes[0]) result--; return result; } //------------------------------------------------------------------------------ // PolyNode methods ... //------------------------------------------------------------------------------ PolyNode::PolyNode(): Childs(), Parent(0), Index(0), m_IsOpen(false) { } //------------------------------------------------------------------------------ int PolyNode::ChildCount() const { return (int)Childs.size(); } //------------------------------------------------------------------------------ void PolyNode::AddChild(PolyNode& child) { unsigned cnt = (unsigned)Childs.size(); Childs.push_back(&child); child.Parent = this; child.Index = cnt; } //------------------------------------------------------------------------------ PolyNode* PolyNode::GetNext() const { if (!Childs.empty()) return Childs[0]; else return GetNextSiblingUp(); } //------------------------------------------------------------------------------ PolyNode* PolyNode::GetNextSiblingUp() const { if (!Parent) //protects against PolyTree.GetNextSiblingUp() return 0; else if (Index == Parent->Childs.size() - 1) return Parent->GetNextSiblingUp(); else return Parent->Childs[Index + 1]; } //------------------------------------------------------------------------------ bool PolyNode::IsHole() const { bool result = true; PolyNode* node = Parent; while (node) { result = !result; node = node->Parent; } return result; } //------------------------------------------------------------------------------ bool PolyNode::IsOpen() const { return m_IsOpen; } //------------------------------------------------------------------------------ #ifndef use_int32 //------------------------------------------------------------------------------ // Int128 class (enables safe math on signed 64bit integers) // eg Int128 val1((long64)9223372036854775807); //ie 2^63 -1 // Int128 val2((long64)9223372036854775807); // Int128 val3 = val1 * val2; // val3.AsString => "85070591730234615847396907784232501249" (8.5e+37) //------------------------------------------------------------------------------ class Int128 { public: ulong64 lo; long64 hi; Int128(long64 _lo = 0) { lo = (ulong64)_lo; if (_lo < 0) hi = -1; else hi = 0; } Int128(const Int128 &val): lo(val.lo), hi(val.hi){} Int128(const long64& _hi, const ulong64& _lo): lo(_lo), hi(_hi){} Int128& operator = (const long64 &val) { lo = (ulong64)val; if (val < 0) hi = -1; else hi = 0; return *this; } bool operator == (const Int128 &val) const {return (hi == val.hi && lo == val.lo);} bool operator != (const Int128 &val) const { return !(*this == val);} bool operator > (const Int128 &val) const { if (hi != val.hi) return hi > val.hi; else return lo > val.lo; } bool operator < (const Int128 &val) const { if (hi != val.hi) return hi < val.hi; else return lo < val.lo; } bool operator >= (const Int128 &val) const { return !(*this < val);} bool operator <= (const Int128 &val) const { return !(*this > val);} Int128& operator += (const Int128 &rhs) { hi += rhs.hi; lo += rhs.lo; if (lo < rhs.lo) hi++; return *this; } Int128 operator + (const Int128 &rhs) const { Int128 result(*this); result+= rhs; return result; } Int128& operator -= (const Int128 &rhs) { *this += -rhs; return *this; } Int128 operator - (const Int128 &rhs) const { Int128 result(*this); result -= rhs; return result; } Int128 operator-() const //unary negation { if (lo == 0) return Int128(-hi, 0); else return Int128(~hi, ~lo + 1); } operator double() const { const double shift64 = 18446744073709551616.0; //2^64 if (hi < 0) { if (lo == 0) return (double)hi * shift64; else return -(double)(~lo + ~hi * shift64); } else return (double)(lo + hi * shift64); } }; //------------------------------------------------------------------------------ Int128 Int128Mul (long64 lhs, long64 rhs) { bool negate = (lhs < 0) != (rhs < 0); if (lhs < 0) lhs = -lhs; ulong64 int1Hi = ulong64(lhs) >> 32; ulong64 int1Lo = ulong64(lhs & 0xFFFFFFFF); if (rhs < 0) rhs = -rhs; ulong64 int2Hi = ulong64(rhs) >> 32; ulong64 int2Lo = ulong64(rhs & 0xFFFFFFFF); //nb: see comments in clipper.pas ulong64 a = int1Hi * int2Hi; ulong64 b = int1Lo * int2Lo; ulong64 c = int1Hi * int2Lo + int1Lo * int2Hi; Int128 tmp; tmp.hi = long64(a + (c >> 32)); tmp.lo = long64(c << 32); tmp.lo += long64(b); if (tmp.lo < b) tmp.hi++; if (negate) tmp = -tmp; return tmp; }; #endif //------------------------------------------------------------------------------ // Miscellaneous global functions //------------------------------------------------------------------------------ bool Orientation(const Path &poly) { return Area(poly) >= 0; } //------------------------------------------------------------------------------ double Area(const Path &poly) { int size = (int)poly.size(); if (size < 3) return 0; double a = 0; for (int i = 0, j = size -1; i < size; ++i) { a += ((double)poly[j].X + poly[i].X) * ((double)poly[j].Y - poly[i].Y); j = i; } return -a * 0.5; } //------------------------------------------------------------------------------ double Area(const OutPt *op) { const OutPt *startOp = op; if (!op) return 0; double a = 0; do { a += (double)(op->Prev->Pt.X + op->Pt.X) * (double)(op->Prev->Pt.Y - op->Pt.Y); op = op->Next; } while (op != startOp); return a * 0.5; } //------------------------------------------------------------------------------ double Area(const OutRec &outRec) { return Area(outRec.Pts); } //------------------------------------------------------------------------------ bool PointIsVertex(const IntPoint &Pt, OutPt *pp) { OutPt *pp2 = pp; do { if (pp2->Pt == Pt) return true; pp2 = pp2->Next; } while (pp2 != pp); return false; } //------------------------------------------------------------------------------ //See "The Point in Polygon Problem for Arbitrary Polygons" by Hormann & Agathos //http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf int PointInPolygon(const IntPoint &pt, const Path &path) { //returns 0 if false, +1 if true, -1 if pt ON polygon boundary int result = 0; size_t cnt = path.size(); if (cnt < 3) return 0; IntPoint ip = path[0]; for(size_t i = 1; i <= cnt; ++i) { IntPoint ipNext = (i == cnt ? path[0] : path[i]); if (ipNext.Y == pt.Y) { if ((ipNext.X == pt.X) || (ip.Y == pt.Y && ((ipNext.X > pt.X) == (ip.X < pt.X)))) return -1; } if ((ip.Y < pt.Y) != (ipNext.Y < pt.Y)) { if (ip.X >= pt.X) { if (ipNext.X > pt.X) result = 1 - result; else { double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) - (double)(ipNext.X - pt.X) * (ip.Y - pt.Y); if (!d) return -1; if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result; } } else { if (ipNext.X > pt.X) { double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) - (double)(ipNext.X - pt.X) * (ip.Y - pt.Y); if (!d) return -1; if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result; } } } ip = ipNext; } return result; } //------------------------------------------------------------------------------ int PointInPolygon (const IntPoint &pt, OutPt *op) { //returns 0 if false, +1 if true, -1 if pt ON polygon boundary int result = 0; OutPt* startOp = op; for(;;) { if (op->Next->Pt.Y == pt.Y) { if ((op->Next->Pt.X == pt.X) || (op->Pt.Y == pt.Y && ((op->Next->Pt.X > pt.X) == (op->Pt.X < pt.X)))) return -1; } if ((op->Pt.Y < pt.Y) != (op->Next->Pt.Y < pt.Y)) { if (op->Pt.X >= pt.X) { if (op->Next->Pt.X > pt.X) result = 1 - result; else { double d = (double)(op->Pt.X - pt.X) * (op->Next->Pt.Y - pt.Y) - (double)(op->Next->Pt.X - pt.X) * (op->Pt.Y - pt.Y); if (!d) return -1; if ((d > 0) == (op->Next->Pt.Y > op->Pt.Y)) result = 1 - result; } } else { if (op->Next->Pt.X > pt.X) { double d = (double)(op->Pt.X - pt.X) * (op->Next->Pt.Y - pt.Y) - (double)(op->Next->Pt.X - pt.X) * (op->Pt.Y - pt.Y); if (!d) return -1; if ((d > 0) == (op->Next->Pt.Y > op->Pt.Y)) result = 1 - result; } } } op = op->Next; if (startOp == op) break; } return result; } //------------------------------------------------------------------------------ bool Poly2ContainsPoly1(OutPt *OutPt1, OutPt *OutPt2) { OutPt* op = OutPt1; do { //nb: PointInPolygon returns 0 if false, +1 if true, -1 if pt on polygon int res = PointInPolygon(op->Pt, OutPt2); if (res >= 0) return res > 0; op = op->Next; } while (op != OutPt1); return true; } //---------------------------------------------------------------------- bool SlopesEqual(const TEdge &e1, const TEdge &e2, bool UseFullInt64Range) { #ifndef use_int32 if (UseFullInt64Range) return Int128Mul(e1.Top.Y - e1.Bot.Y, e2.Top.X - e2.Bot.X) == Int128Mul(e1.Top.X - e1.Bot.X, e2.Top.Y - e2.Bot.Y); else #endif return (e1.Top.Y - e1.Bot.Y) * (e2.Top.X - e2.Bot.X) == (e1.Top.X - e1.Bot.X) * (e2.Top.Y - e2.Bot.Y); } //------------------------------------------------------------------------------ bool SlopesEqual(const IntPoint pt1, const IntPoint pt2, const IntPoint pt3, bool UseFullInt64Range) { #ifndef use_int32 if (UseFullInt64Range) return Int128Mul(pt1.Y-pt2.Y, pt2.X-pt3.X) == Int128Mul(pt1.X-pt2.X, pt2.Y-pt3.Y); else #endif return (pt1.Y-pt2.Y)*(pt2.X-pt3.X) == (pt1.X-pt2.X)*(pt2.Y-pt3.Y); } //------------------------------------------------------------------------------ bool SlopesEqual(const IntPoint pt1, const IntPoint pt2, const IntPoint pt3, const IntPoint pt4, bool UseFullInt64Range) { #ifndef use_int32 if (UseFullInt64Range) return Int128Mul(pt1.Y-pt2.Y, pt3.X-pt4.X) == Int128Mul(pt1.X-pt2.X, pt3.Y-pt4.Y); else #endif return (pt1.Y-pt2.Y)*(pt3.X-pt4.X) == (pt1.X-pt2.X)*(pt3.Y-pt4.Y); } //------------------------------------------------------------------------------ inline bool IsHorizontal(TEdge &e) { return e.Dx == HORIZONTAL; } //------------------------------------------------------------------------------ inline double GetDx(const IntPoint pt1, const IntPoint pt2) { return (pt1.Y == pt2.Y) ? HORIZONTAL : (double)(pt2.X - pt1.X) / (pt2.Y - pt1.Y); } //--------------------------------------------------------------------------- inline void SetDx(TEdge &e) { cInt dy = (e.Top.Y - e.Bot.Y); if (dy == 0) e.Dx = HORIZONTAL; else e.Dx = (double)(e.Top.X - e.Bot.X) / dy; } //--------------------------------------------------------------------------- inline void SwapSides(TEdge &Edge1, TEdge &Edge2) { EdgeSide Side = Edge1.Side; Edge1.Side = Edge2.Side; Edge2.Side = Side; } //------------------------------------------------------------------------------ inline void SwapPolyIndexes(TEdge &Edge1, TEdge &Edge2) { int OutIdx = Edge1.OutIdx; Edge1.OutIdx = Edge2.OutIdx; Edge2.OutIdx = OutIdx; } //------------------------------------------------------------------------------ inline cInt TopX(TEdge &edge, const cInt currentY) { return ( currentY == edge.Top.Y ) ? edge.Top.X : edge.Bot.X + Round(edge.Dx *(currentY - edge.Bot.Y)); } //------------------------------------------------------------------------------ void IntersectPoint(TEdge &Edge1, TEdge &Edge2, IntPoint &ip) { #ifdef use_xyz ip.Z = 0; #endif double b1, b2; if (Edge1.Dx == Edge2.Dx) { ip.Y = Edge1.Curr.Y; ip.X = TopX(Edge1, ip.Y); return; } else if (Edge1.Dx == 0) { ip.X = Edge1.Bot.X; if (IsHorizontal(Edge2)) ip.Y = Edge2.Bot.Y; else { b2 = Edge2.Bot.Y - (Edge2.Bot.X / Edge2.Dx); ip.Y = Round(ip.X / Edge2.Dx + b2); } } else if (Edge2.Dx == 0) { ip.X = Edge2.Bot.X; if (IsHorizontal(Edge1)) ip.Y = Edge1.Bot.Y; else { b1 = Edge1.Bot.Y - (Edge1.Bot.X / Edge1.Dx); ip.Y = Round(ip.X / Edge1.Dx + b1); } } else { b1 = Edge1.Bot.X - Edge1.Bot.Y * Edge1.Dx; b2 = Edge2.Bot.X - Edge2.Bot.Y * Edge2.Dx; double q = (b2-b1) / (Edge1.Dx - Edge2.Dx); ip.Y = Round(q); if (std::fabs(Edge1.Dx) < std::fabs(Edge2.Dx)) ip.X = Round(Edge1.Dx * q + b1); else ip.X = Round(Edge2.Dx * q + b2); } if (ip.Y < Edge1.Top.Y || ip.Y < Edge2.Top.Y) { if (Edge1.Top.Y > Edge2.Top.Y) ip.Y = Edge1.Top.Y; else ip.Y = Edge2.Top.Y; if (std::fabs(Edge1.Dx) < std::fabs(Edge2.Dx)) ip.X = TopX(Edge1, ip.Y); else ip.X = TopX(Edge2, ip.Y); } //finally, don't allow 'ip' to be BELOW curr.Y (ie bottom of scanbeam) ... if (ip.Y > Edge1.Curr.Y) { ip.Y = Edge1.Curr.Y; //use the more vertical edge to derive X ... if (std::fabs(Edge1.Dx) > std::fabs(Edge2.Dx)) ip.X = TopX(Edge2, ip.Y); else ip.X = TopX(Edge1, ip.Y); } } //------------------------------------------------------------------------------ void ReversePolyPtLinks(OutPt *pp) { if (!pp) return; OutPt *pp1, *pp2; pp1 = pp; do { pp2 = pp1->Next; pp1->Next = pp1->Prev; pp1->Prev = pp2; pp1 = pp2; } while( pp1 != pp ); } //------------------------------------------------------------------------------ void DisposeOutPts(OutPt*& pp) { if (pp == 0) return; pp->Prev->Next = 0; while( pp ) { OutPt *tmpPp = pp; pp = pp->Next; delete tmpPp; } } //------------------------------------------------------------------------------ inline void InitEdge(TEdge* e, TEdge* eNext, TEdge* ePrev, const IntPoint& Pt) { std::memset(e, 0, sizeof(TEdge)); e->Next = eNext; e->Prev = ePrev; e->Curr = Pt; e->OutIdx = Unassigned; } //------------------------------------------------------------------------------ void InitEdge2(TEdge& e, PolyType Pt) { if (e.Curr.Y >= e.Next->Curr.Y) { e.Bot = e.Curr; e.Top = e.Next->Curr; } else { e.Top = e.Curr; e.Bot = e.Next->Curr; } SetDx(e); e.PolyTyp = Pt; } //------------------------------------------------------------------------------ TEdge* RemoveEdge(TEdge* e) { //removes e from double_linked_list (but without removing from memory) e->Prev->Next = e->Next; e->Next->Prev = e->Prev; TEdge* result = e->Next; e->Prev = 0; //flag as removed (see ClipperBase.Clear) return result; } //------------------------------------------------------------------------------ inline void ReverseHorizontal(TEdge &e) { //swap horizontal edges' Top and Bottom x's so they follow the natural //progression of the bounds - ie so their xbots will align with the //adjoining lower edge. [Helpful in the ProcessHorizontal() method.] std::swap(e.Top.X, e.Bot.X); #ifdef use_xyz std::swap(e.Top.Z, e.Bot.Z); #endif } //------------------------------------------------------------------------------ void SwapPoints(IntPoint &pt1, IntPoint &pt2) { IntPoint tmp = pt1; pt1 = pt2; pt2 = tmp; } //------------------------------------------------------------------------------ bool GetOverlapSegment(IntPoint pt1a, IntPoint pt1b, IntPoint pt2a, IntPoint pt2b, IntPoint &pt1, IntPoint &pt2) { //precondition: segments are Collinear. if (Abs(pt1a.X - pt1b.X) > Abs(pt1a.Y - pt1b.Y)) { if (pt1a.X > pt1b.X) SwapPoints(pt1a, pt1b); if (pt2a.X > pt2b.X) SwapPoints(pt2a, pt2b); if (pt1a.X > pt2a.X) pt1 = pt1a; else pt1 = pt2a; if (pt1b.X < pt2b.X) pt2 = pt1b; else pt2 = pt2b; return pt1.X < pt2.X; } else { if (pt1a.Y < pt1b.Y) SwapPoints(pt1a, pt1b); if (pt2a.Y < pt2b.Y) SwapPoints(pt2a, pt2b); if (pt1a.Y < pt2a.Y) pt1 = pt1a; else pt1 = pt2a; if (pt1b.Y > pt2b.Y) pt2 = pt1b; else pt2 = pt2b; return pt1.Y > pt2.Y; } } //------------------------------------------------------------------------------ bool FirstIsBottomPt(const OutPt* btmPt1, const OutPt* btmPt2) { OutPt *p = btmPt1->Prev; while ((p->Pt == btmPt1->Pt) && (p != btmPt1)) p = p->Prev; double dx1p = std::fabs(GetDx(btmPt1->Pt, p->Pt)); p = btmPt1->Next; while ((p->Pt == btmPt1->Pt) && (p != btmPt1)) p = p->Next; double dx1n = std::fabs(GetDx(btmPt1->Pt, p->Pt)); p = btmPt2->Prev; while ((p->Pt == btmPt2->Pt) && (p != btmPt2)) p = p->Prev; double dx2p = std::fabs(GetDx(btmPt2->Pt, p->Pt)); p = btmPt2->Next; while ((p->Pt == btmPt2->Pt) && (p != btmPt2)) p = p->Next; double dx2n = std::fabs(GetDx(btmPt2->Pt, p->Pt)); if (std::max(dx1p, dx1n) == std::max(dx2p, dx2n) && std::min(dx1p, dx1n) == std::min(dx2p, dx2n)) return Area(btmPt1) > 0; //if otherwise identical use orientation else return (dx1p >= dx2p && dx1p >= dx2n) || (dx1n >= dx2p && dx1n >= dx2n); } //------------------------------------------------------------------------------ OutPt* GetBottomPt(OutPt *pp) { OutPt* dups = 0; OutPt* p = pp->Next; while (p != pp) { if (p->Pt.Y > pp->Pt.Y) { pp = p; dups = 0; } else if (p->Pt.Y == pp->Pt.Y && p->Pt.X <= pp->Pt.X) { if (p->Pt.X < pp->Pt.X) { dups = 0; pp = p; } else { if (p->Next != pp && p->Prev != pp) dups = p; } } p = p->Next; } if (dups) { //there appears to be at least 2 vertices at BottomPt so ... while (dups != p) { if (!FirstIsBottomPt(p, dups)) pp = dups; dups = dups->Next; while (dups->Pt != pp->Pt) dups = dups->Next; } } return pp; } //------------------------------------------------------------------------------ bool Pt2IsBetweenPt1AndPt3(const IntPoint pt1, const IntPoint pt2, const IntPoint pt3) { if ((pt1 == pt3) || (pt1 == pt2) || (pt3 == pt2)) return false; else if (pt1.X != pt3.X) return (pt2.X > pt1.X) == (pt2.X < pt3.X); else return (pt2.Y > pt1.Y) == (pt2.Y < pt3.Y); } //------------------------------------------------------------------------------ bool HorzSegmentsOverlap(cInt seg1a, cInt seg1b, cInt seg2a, cInt seg2b) { if (seg1a > seg1b) std::swap(seg1a, seg1b); if (seg2a > seg2b) std::swap(seg2a, seg2b); return (seg1a < seg2b) && (seg2a < seg1b); } //------------------------------------------------------------------------------ // ClipperBase class methods ... //------------------------------------------------------------------------------ ClipperBase::ClipperBase() //constructor { m_CurrentLM = m_MinimaList.begin(); //begin() == end() here m_UseFullRange = false; } //------------------------------------------------------------------------------ ClipperBase::~ClipperBase() //destructor { Clear(); } //------------------------------------------------------------------------------ void RangeTest(const IntPoint& Pt, bool& useFullRange) { if (useFullRange) { if (Pt.X > hiRange || Pt.Y > hiRange || -Pt.X > hiRange || -Pt.Y > hiRange) throw clipperException("Coordinate outside allowed range"); } else if (Pt.X > loRange|| Pt.Y > loRange || -Pt.X > loRange || -Pt.Y > loRange) { useFullRange = true; RangeTest(Pt, useFullRange); } } //------------------------------------------------------------------------------ TEdge* FindNextLocMin(TEdge* E) { for (;;) { while (E->Bot != E->Prev->Bot || E->Curr == E->Top) E = E->Next; if (!IsHorizontal(*E) && !IsHorizontal(*E->Prev)) break; while (IsHorizontal(*E->Prev)) E = E->Prev; TEdge* E2 = E; while (IsHorizontal(*E)) E = E->Next; if (E->Top.Y == E->Prev->Bot.Y) continue; //ie just an intermediate horz. if (E2->Prev->Bot.X < E->Bot.X) E = E2; break; } return E; } //------------------------------------------------------------------------------ TEdge* ClipperBase::ProcessBound(TEdge* E, bool NextIsForward) { TEdge *Result = E; TEdge *Horz = 0; if (E->OutIdx == Skip) { //if edges still remain in the current bound beyond the skip edge then //create another LocMin and call ProcessBound once more if (NextIsForward) { while (E->Top.Y == E->Next->Bot.Y) E = E->Next; //don't include top horizontals when parsing a bound a second time, //they will be contained in the opposite bound ... while (E != Result && IsHorizontal(*E)) E = E->Prev; } else { while (E->Top.Y == E->Prev->Bot.Y) E = E->Prev; while (E != Result && IsHorizontal(*E)) E = E->Next; } if (E == Result) { if (NextIsForward) Result = E->Next; else Result = E->Prev; } else { //there are more edges in the bound beyond result starting with E if (NextIsForward) E = Result->Next; else E = Result->Prev; MinimaList::value_type locMin; locMin.Y = E->Bot.Y; locMin.LeftBound = 0; locMin.RightBound = E; E->WindDelta = 0; Result = ProcessBound(E, NextIsForward); m_MinimaList.push_back(locMin); } return Result; } TEdge *EStart; if (IsHorizontal(*E)) { //We need to be careful with open paths because this may not be a //true local minima (ie E may be following a skip edge). //Also, consecutive horz. edges may start heading left before going right. if (NextIsForward) EStart = E->Prev; else EStart = E->Next; if (IsHorizontal(*EStart)) //ie an adjoining horizontal skip edge { if (EStart->Bot.X != E->Bot.X && EStart->Top.X != E->Bot.X) ReverseHorizontal(*E); } else if (EStart->Bot.X != E->Bot.X) ReverseHorizontal(*E); } EStart = E; if (NextIsForward) { while (Result->Top.Y == Result->Next->Bot.Y && Result->Next->OutIdx != Skip) Result = Result->Next; if (IsHorizontal(*Result) && Result->Next->OutIdx != Skip) { //nb: at the top of a bound, horizontals are added to the bound //only when the preceding edge attaches to the horizontal's left vertex //unless a Skip edge is encountered when that becomes the top divide Horz = Result; while (IsHorizontal(*Horz->Prev)) Horz = Horz->Prev; if (Horz->Prev->Top.X > Result->Next->Top.X) Result = Horz->Prev; } while (E != Result) { E->NextInLML = E->Next; if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E); E = E->Next; } if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E); Result = Result->Next; //move to the edge just beyond current bound } else { while (Result->Top.Y == Result->Prev->Bot.Y && Result->Prev->OutIdx != Skip) Result = Result->Prev; if (IsHorizontal(*Result) && Result->Prev->OutIdx != Skip) { Horz = Result; while (IsHorizontal(*Horz->Next)) Horz = Horz->Next; if (Horz->Next->Top.X == Result->Prev->Top.X || Horz->Next->Top.X > Result->Prev->Top.X) Result = Horz->Next; } while (E != Result) { E->NextInLML = E->Prev; if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Next->Top.X) ReverseHorizontal(*E); E = E->Prev; } if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Next->Top.X) ReverseHorizontal(*E); Result = Result->Prev; //move to the edge just beyond current bound } return Result; } //------------------------------------------------------------------------------ bool ClipperBase::AddPath(const Path &pg, PolyType PolyTyp, bool Closed) { #ifdef use_lines if (!Closed && PolyTyp == ptClip) throw clipperException("AddPath: Open paths must be subject."); #else if (!Closed) throw clipperException("AddPath: Open paths have been disabled."); #endif int highI = (int)pg.size() -1; if (Closed) while (highI > 0 && (pg[highI] == pg[0])) --highI; while (highI > 0 && (pg[highI] == pg[highI -1])) --highI; if ((Closed && highI < 2) || (!Closed && highI < 1)) return false; //create a new edge array ... TEdge *edges = new TEdge [highI +1]; bool IsFlat = true; //1. Basic (first) edge initialization ... try { edges[1].Curr = pg[1]; RangeTest(pg[0], m_UseFullRange); RangeTest(pg[highI], m_UseFullRange); InitEdge(&edges[0], &edges[1], &edges[highI], pg[0]); InitEdge(&edges[highI], &edges[0], &edges[highI-1], pg[highI]); for (int i = highI - 1; i >= 1; --i) { RangeTest(pg[i], m_UseFullRange); InitEdge(&edges[i], &edges[i+1], &edges[i-1], pg[i]); } } catch(...) { delete [] edges; throw; //range test fails } TEdge *eStart = &edges[0]; //2. Remove duplicate vertices, and (when closed) collinear edges ... TEdge *E = eStart, *eLoopStop = eStart; for (;;) { //nb: allows matching start and end points when not Closed ... if (E->Curr == E->Next->Curr && (Closed || E->Next != eStart)) { if (E == E->Next) break; if (E == eStart) eStart = E->Next; E = RemoveEdge(E); eLoopStop = E; continue; } if (E->Prev == E->Next) break; //only two vertices else if (Closed && SlopesEqual(E->Prev->Curr, E->Curr, E->Next->Curr, m_UseFullRange) && (!m_PreserveCollinear || !Pt2IsBetweenPt1AndPt3(E->Prev->Curr, E->Curr, E->Next->Curr))) { //Collinear edges are allowed for open paths but in closed paths //the default is to merge adjacent collinear edges into a single edge. //However, if the PreserveCollinear property is enabled, only overlapping //collinear edges (ie spikes) will be removed from closed paths. if (E == eStart) eStart = E->Next; E = RemoveEdge(E); E = E->Prev; eLoopStop = E; continue; } E = E->Next; if ((E == eLoopStop) || (!Closed && E->Next == eStart)) break; } if ((!Closed && (E == E->Next)) || (Closed && (E->Prev == E->Next))) { delete [] edges; return false; } if (!Closed) { m_HasOpenPaths = true; eStart->Prev->OutIdx = Skip; } //3. Do second stage of edge initialization ... E = eStart; do { InitEdge2(*E, PolyTyp); E = E->Next; if (IsFlat && E->Curr.Y != eStart->Curr.Y) IsFlat = false; } while (E != eStart); //4. Finally, add edge bounds to LocalMinima list ... //Totally flat paths must be handled differently when adding them //to LocalMinima list to avoid endless loops etc ... if (IsFlat) { if (Closed) { delete [] edges; return false; } E->Prev->OutIdx = Skip; MinimaList::value_type locMin; locMin.Y = E->Bot.Y; locMin.LeftBound = 0; locMin.RightBound = E; locMin.RightBound->Side = esRight; locMin.RightBound->WindDelta = 0; for (;;) { if (E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E); if (E->Next->OutIdx == Skip) break; E->NextInLML = E->Next; E = E->Next; } m_MinimaList.push_back(locMin); m_edges.push_back(edges); return true; } m_edges.push_back(edges); bool leftBoundIsForward; TEdge* EMin = 0; //workaround to avoid an endless loop in the while loop below when //open paths have matching start and end points ... if (E->Prev->Bot == E->Prev->Top) E = E->Next; for (;;) { E = FindNextLocMin(E); if (E == EMin) break; else if (!EMin) EMin = E; //E and E.Prev now share a local minima (left aligned if horizontal). //Compare their slopes to find which starts which bound ... MinimaList::value_type locMin; locMin.Y = E->Bot.Y; if (E->Dx < E->Prev->Dx) { locMin.LeftBound = E->Prev; locMin.RightBound = E; leftBoundIsForward = false; //Q.nextInLML = Q.prev } else { locMin.LeftBound = E; locMin.RightBound = E->Prev; leftBoundIsForward = true; //Q.nextInLML = Q.next } if (!Closed) locMin.LeftBound->WindDelta = 0; else if (locMin.LeftBound->Next == locMin.RightBound) locMin.LeftBound->WindDelta = -1; else locMin.LeftBound->WindDelta = 1; locMin.RightBound->WindDelta = -locMin.LeftBound->WindDelta; E = ProcessBound(locMin.LeftBound, leftBoundIsForward); if (E->OutIdx == Skip) E = ProcessBound(E, leftBoundIsForward); TEdge* E2 = ProcessBound(locMin.RightBound, !leftBoundIsForward); if (E2->OutIdx == Skip) E2 = ProcessBound(E2, !leftBoundIsForward); if (locMin.LeftBound->OutIdx == Skip) locMin.LeftBound = 0; else if (locMin.RightBound->OutIdx == Skip) locMin.RightBound = 0; m_MinimaList.push_back(locMin); if (!leftBoundIsForward) E = E2; } return true; } //------------------------------------------------------------------------------ bool ClipperBase::AddPaths(const Paths &ppg, PolyType PolyTyp, bool Closed) { bool result = false; for (Paths::size_type i = 0; i < ppg.size(); ++i) if (AddPath(ppg[i], PolyTyp, Closed)) result = true; return result; } //------------------------------------------------------------------------------ void ClipperBase::Clear() { DisposeLocalMinimaList(); for (EdgeList::size_type i = 0; i < m_edges.size(); ++i) { TEdge* edges = m_edges[i]; delete [] edges; } m_edges.clear(); m_UseFullRange = false; m_HasOpenPaths = false; } //------------------------------------------------------------------------------ void ClipperBase::Reset() { m_CurrentLM = m_MinimaList.begin(); if (m_CurrentLM == m_MinimaList.end()) return; //ie nothing to process std::sort(m_MinimaList.begin(), m_MinimaList.end(), LocMinSorter()); m_Scanbeam = ScanbeamList(); //clears/resets priority_queue //reset all edges ... for (MinimaList::iterator lm = m_MinimaList.begin(); lm != m_MinimaList.end(); ++lm) { InsertScanbeam(lm->Y); TEdge* e = lm->LeftBound; if (e) { e->Curr = e->Bot; e->Side = esLeft; e->OutIdx = Unassigned; } e = lm->RightBound; if (e) { e->Curr = e->Bot; e->Side = esRight; e->OutIdx = Unassigned; } } m_ActiveEdges = 0; m_CurrentLM = m_MinimaList.begin(); } //------------------------------------------------------------------------------ void ClipperBase::DisposeLocalMinimaList() { m_MinimaList.clear(); m_CurrentLM = m_MinimaList.begin(); } //------------------------------------------------------------------------------ bool ClipperBase::PopLocalMinima(cInt Y, const LocalMinimum *&locMin) { if (m_CurrentLM == m_MinimaList.end() || (*m_CurrentLM).Y != Y) return false; locMin = &(*m_CurrentLM); ++m_CurrentLM; return true; } //------------------------------------------------------------------------------ IntRect ClipperBase::GetBounds() { IntRect result; MinimaList::iterator lm = m_MinimaList.begin(); if (lm == m_MinimaList.end()) { result.left = result.top = result.right = result.bottom = 0; return result; } result.left = lm->LeftBound->Bot.X; result.top = lm->LeftBound->Bot.Y; result.right = lm->LeftBound->Bot.X; result.bottom = lm->LeftBound->Bot.Y; while (lm != m_MinimaList.end()) { //todo - needs fixing for open paths result.bottom = std::max(result.bottom, lm->LeftBound->Bot.Y); TEdge* e = lm->LeftBound; for (;;) { TEdge* bottomE = e; while (e->NextInLML) { if (e->Bot.X < result.left) result.left = e->Bot.X; if (e->Bot.X > result.right) result.right = e->Bot.X; e = e->NextInLML; } result.left = std::min(result.left, e->Bot.X); result.right = std::max(result.right, e->Bot.X); result.left = std::min(result.left, e->Top.X); result.right = std::max(result.right, e->Top.X); result.top = std::min(result.top, e->Top.Y); if (bottomE == lm->LeftBound) e = lm->RightBound; else break; } ++lm; } return result; } //------------------------------------------------------------------------------ void ClipperBase::InsertScanbeam(const cInt Y) { m_Scanbeam.push(Y); } //------------------------------------------------------------------------------ bool ClipperBase::PopScanbeam(cInt &Y) { if (m_Scanbeam.empty()) return false; Y = m_Scanbeam.top(); m_Scanbeam.pop(); while (!m_Scanbeam.empty() && Y == m_Scanbeam.top()) { m_Scanbeam.pop(); } // Pop duplicates. return true; } //------------------------------------------------------------------------------ void ClipperBase::DisposeAllOutRecs(){ for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i) DisposeOutRec(i); m_PolyOuts.clear(); } //------------------------------------------------------------------------------ void ClipperBase::DisposeOutRec(PolyOutList::size_type index) { OutRec *outRec = m_PolyOuts[index]; if (outRec->Pts) DisposeOutPts(outRec->Pts); delete outRec; m_PolyOuts[index] = 0; } //------------------------------------------------------------------------------ void ClipperBase::DeleteFromAEL(TEdge *e) { TEdge* AelPrev = e->PrevInAEL; TEdge* AelNext = e->NextInAEL; if (!AelPrev && !AelNext && (e != m_ActiveEdges)) return; //already deleted if (AelPrev) AelPrev->NextInAEL = AelNext; else m_ActiveEdges = AelNext; if (AelNext) AelNext->PrevInAEL = AelPrev; e->NextInAEL = 0; e->PrevInAEL = 0; } //------------------------------------------------------------------------------ OutRec* ClipperBase::CreateOutRec() { OutRec* result = new OutRec; result->IsHole = false; result->IsOpen = false; result->FirstLeft = 0; result->Pts = 0; result->BottomPt = 0; result->PolyNd = 0; m_PolyOuts.push_back(result); result->Idx = (int)m_PolyOuts.size() - 1; return result; } //------------------------------------------------------------------------------ void ClipperBase::SwapPositionsInAEL(TEdge *Edge1, TEdge *Edge2) { //check that one or other edge hasn't already been removed from AEL ... if (Edge1->NextInAEL == Edge1->PrevInAEL || Edge2->NextInAEL == Edge2->PrevInAEL) return; if (Edge1->NextInAEL == Edge2) { TEdge* Next = Edge2->NextInAEL; if (Next) Next->PrevInAEL = Edge1; TEdge* Prev = Edge1->PrevInAEL; if (Prev) Prev->NextInAEL = Edge2; Edge2->PrevInAEL = Prev; Edge2->NextInAEL = Edge1; Edge1->PrevInAEL = Edge2; Edge1->NextInAEL = Next; } else if (Edge2->NextInAEL == Edge1) { TEdge* Next = Edge1->NextInAEL; if (Next) Next->PrevInAEL = Edge2; TEdge* Prev = Edge2->PrevInAEL; if (Prev) Prev->NextInAEL = Edge1; Edge1->PrevInAEL = Prev; Edge1->NextInAEL = Edge2; Edge2->PrevInAEL = Edge1; Edge2->NextInAEL = Next; } else { TEdge* Next = Edge1->NextInAEL; TEdge* Prev = Edge1->PrevInAEL; Edge1->NextInAEL = Edge2->NextInAEL; if (Edge1->NextInAEL) Edge1->NextInAEL->PrevInAEL = Edge1; Edge1->PrevInAEL = Edge2->PrevInAEL; if (Edge1->PrevInAEL) Edge1->PrevInAEL->NextInAEL = Edge1; Edge2->NextInAEL = Next; if (Edge2->NextInAEL) Edge2->NextInAEL->PrevInAEL = Edge2; Edge2->PrevInAEL = Prev; if (Edge2->PrevInAEL) Edge2->PrevInAEL->NextInAEL = Edge2; } if (!Edge1->PrevInAEL) m_ActiveEdges = Edge1; else if (!Edge2->PrevInAEL) m_ActiveEdges = Edge2; } //------------------------------------------------------------------------------ void ClipperBase::UpdateEdgeIntoAEL(TEdge *&e) { if (!e->NextInLML) throw clipperException("UpdateEdgeIntoAEL: invalid call"); e->NextInLML->OutIdx = e->OutIdx; TEdge* AelPrev = e->PrevInAEL; TEdge* AelNext = e->NextInAEL; if (AelPrev) AelPrev->NextInAEL = e->NextInLML; else m_ActiveEdges = e->NextInLML; if (AelNext) AelNext->PrevInAEL = e->NextInLML; e->NextInLML->Side = e->Side; e->NextInLML->WindDelta = e->WindDelta; e->NextInLML->WindCnt = e->WindCnt; e->NextInLML->WindCnt2 = e->WindCnt2; e = e->NextInLML; e->Curr = e->Bot; e->PrevInAEL = AelPrev; e->NextInAEL = AelNext; if (!IsHorizontal(*e)) InsertScanbeam(e->Top.Y); } //------------------------------------------------------------------------------ bool ClipperBase::LocalMinimaPending() { return (m_CurrentLM != m_MinimaList.end()); } //------------------------------------------------------------------------------ // TClipper methods ... //------------------------------------------------------------------------------ Clipper::Clipper(int initOptions) : ClipperBase() //constructor { m_ExecuteLocked = false; m_UseFullRange = false; m_ReverseOutput = ((initOptions & ioReverseSolution) != 0); m_StrictSimple = ((initOptions & ioStrictlySimple) != 0); m_PreserveCollinear = ((initOptions & ioPreserveCollinear) != 0); m_HasOpenPaths = false; #ifdef use_xyz m_ZFill = 0; #endif } //------------------------------------------------------------------------------ #ifdef use_xyz void Clipper::ZFillFunction(ZFillCallback zFillFunc) { m_ZFill = zFillFunc; } //------------------------------------------------------------------------------ #endif bool Clipper::Execute(ClipType clipType, Paths &solution, PolyFillType fillType) { return Execute(clipType, solution, fillType, fillType); } //------------------------------------------------------------------------------ bool Clipper::Execute(ClipType clipType, PolyTree &polytree, PolyFillType fillType) { return Execute(clipType, polytree, fillType, fillType); } //------------------------------------------------------------------------------ bool Clipper::Execute(ClipType clipType, Paths &solution, PolyFillType subjFillType, PolyFillType clipFillType) { if( m_ExecuteLocked ) return false; if (m_HasOpenPaths) throw clipperException("Error: PolyTree struct is needed for open path clipping."); m_ExecuteLocked = true; solution.resize(0); m_SubjFillType = subjFillType; m_ClipFillType = clipFillType; m_ClipType = clipType; m_UsingPolyTree = false; bool succeeded = ExecuteInternal(); if (succeeded) BuildResult(solution); DisposeAllOutRecs(); m_ExecuteLocked = false; return succeeded; } //------------------------------------------------------------------------------ bool Clipper::Execute(ClipType clipType, PolyTree& polytree, PolyFillType subjFillType, PolyFillType clipFillType) { if( m_ExecuteLocked ) return false; m_ExecuteLocked = true; m_SubjFillType = subjFillType; m_ClipFillType = clipFillType; m_ClipType = clipType; m_UsingPolyTree = true; bool succeeded = ExecuteInternal(); if (succeeded) BuildResult2(polytree); DisposeAllOutRecs(); m_ExecuteLocked = false; return succeeded; } //------------------------------------------------------------------------------ void Clipper::FixHoleLinkage(OutRec &outrec) { //skip OutRecs that (a) contain outermost polygons or //(b) already have the correct owner/child linkage ... if (!outrec.FirstLeft || (outrec.IsHole != outrec.FirstLeft->IsHole && outrec.FirstLeft->Pts)) return; OutRec* orfl = outrec.FirstLeft; while (orfl && ((orfl->IsHole == outrec.IsHole) || !orfl->Pts)) orfl = orfl->FirstLeft; outrec.FirstLeft = orfl; } //------------------------------------------------------------------------------ bool Clipper::ExecuteInternal() { bool succeeded = true; try { Reset(); m_Maxima = MaximaList(); m_SortedEdges = 0; succeeded = true; cInt botY, topY; if (!PopScanbeam(botY)) return false; InsertLocalMinimaIntoAEL(botY); while (PopScanbeam(topY) || LocalMinimaPending()) { ProcessHorizontals(); ClearGhostJoins(); if (!ProcessIntersections(topY)) { succeeded = false; break; } ProcessEdgesAtTopOfScanbeam(topY); botY = topY; InsertLocalMinimaIntoAEL(botY); } } catch(...) { succeeded = false; } if (succeeded) { //fix orientations ... for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i) { OutRec *outRec = m_PolyOuts[i]; if (!outRec->Pts || outRec->IsOpen) continue; if ((outRec->IsHole ^ m_ReverseOutput) == (Area(*outRec) > 0)) ReversePolyPtLinks(outRec->Pts); } if (!m_Joins.empty()) JoinCommonEdges(); //unfortunately FixupOutPolygon() must be done after JoinCommonEdges() for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i) { OutRec *outRec = m_PolyOuts[i]; if (!outRec->Pts) continue; if (outRec->IsOpen) FixupOutPolyline(*outRec); else FixupOutPolygon(*outRec); } if (m_StrictSimple) DoSimplePolygons(); } ClearJoins(); ClearGhostJoins(); return succeeded; } //------------------------------------------------------------------------------ void Clipper::SetWindingCount(TEdge &edge) { TEdge *e = edge.PrevInAEL; //find the edge of the same polytype that immediately preceeds 'edge' in AEL while (e && ((e->PolyTyp != edge.PolyTyp) || (e->WindDelta == 0))) e = e->PrevInAEL; if (!e) { if (edge.WindDelta == 0) { PolyFillType pft = (edge.PolyTyp == ptSubject ? m_SubjFillType : m_ClipFillType); edge.WindCnt = (pft == pftNegative ? -1 : 1); } else edge.WindCnt = edge.WindDelta; edge.WindCnt2 = 0; e = m_ActiveEdges; //ie get ready to calc WindCnt2 } else if (edge.WindDelta == 0 && m_ClipType != ctUnion) { edge.WindCnt = 1; edge.WindCnt2 = e->WindCnt2; e = e->NextInAEL; //ie get ready to calc WindCnt2 } else if (IsEvenOddFillType(edge)) { //EvenOdd filling ... if (edge.WindDelta == 0) { //are we inside a subj polygon ... bool Inside = true; TEdge *e2 = e->PrevInAEL; while (e2) { if (e2->PolyTyp == e->PolyTyp && e2->WindDelta != 0) Inside = !Inside; e2 = e2->PrevInAEL; } edge.WindCnt = (Inside ? 0 : 1); } else { edge.WindCnt = edge.WindDelta; } edge.WindCnt2 = e->WindCnt2; e = e->NextInAEL; //ie get ready to calc WindCnt2 } else { //nonZero, Positive or Negative filling ... if (e->WindCnt * e->WindDelta < 0) { //prev edge is 'decreasing' WindCount (WC) toward zero //so we're outside the previous polygon ... if (Abs(e->WindCnt) > 1) { //outside prev poly but still inside another. //when reversing direction of prev poly use the same WC if (e->WindDelta * edge.WindDelta < 0) edge.WindCnt = e->WindCnt; //otherwise continue to 'decrease' WC ... else edge.WindCnt = e->WindCnt + edge.WindDelta; } else //now outside all polys of same polytype so set own WC ... edge.WindCnt = (edge.WindDelta == 0 ? 1 : edge.WindDelta); } else { //prev edge is 'increasing' WindCount (WC) away from zero //so we're inside the previous polygon ... if (edge.WindDelta == 0) edge.WindCnt = (e->WindCnt < 0 ? e->WindCnt - 1 : e->WindCnt + 1); //if wind direction is reversing prev then use same WC else if (e->WindDelta * edge.WindDelta < 0) edge.WindCnt = e->WindCnt; //otherwise add to WC ... else edge.WindCnt = e->WindCnt + edge.WindDelta; } edge.WindCnt2 = e->WindCnt2; e = e->NextInAEL; //ie get ready to calc WindCnt2 } //update WindCnt2 ... if (IsEvenOddAltFillType(edge)) { //EvenOdd filling ... while (e != &edge) { if (e->WindDelta != 0) edge.WindCnt2 = (edge.WindCnt2 == 0 ? 1 : 0); e = e->NextInAEL; } } else { //nonZero, Positive or Negative filling ... while ( e != &edge ) { edge.WindCnt2 += e->WindDelta; e = e->NextInAEL; } } } //------------------------------------------------------------------------------ bool Clipper::IsEvenOddFillType(const TEdge& edge) const { if (edge.PolyTyp == ptSubject) return m_SubjFillType == pftEvenOdd; else return m_ClipFillType == pftEvenOdd; } //------------------------------------------------------------------------------ bool Clipper::IsEvenOddAltFillType(const TEdge& edge) const { if (edge.PolyTyp == ptSubject) return m_ClipFillType == pftEvenOdd; else return m_SubjFillType == pftEvenOdd; } //------------------------------------------------------------------------------ bool Clipper::IsContributing(const TEdge& edge) const { PolyFillType pft, pft2; if (edge.PolyTyp == ptSubject) { pft = m_SubjFillType; pft2 = m_ClipFillType; } else { pft = m_ClipFillType; pft2 = m_SubjFillType; } switch(pft) { case pftEvenOdd: //return false if a subj line has been flagged as inside a subj polygon if (edge.WindDelta == 0 && edge.WindCnt != 1) return false; break; case pftNonZero: if (Abs(edge.WindCnt) != 1) return false; break; case pftPositive: if (edge.WindCnt != 1) return false; break; default: //pftNegative if (edge.WindCnt != -1) return false; } switch(m_ClipType) { case ctIntersection: switch(pft2) { case pftEvenOdd: case pftNonZero: return (edge.WindCnt2 != 0); case pftPositive: return (edge.WindCnt2 > 0); default: return (edge.WindCnt2 < 0); } break; case ctUnion: switch(pft2) { case pftEvenOdd: case pftNonZero: return (edge.WindCnt2 == 0); case pftPositive: return (edge.WindCnt2 <= 0); default: return (edge.WindCnt2 >= 0); } break; case ctDifference: if (edge.PolyTyp == ptSubject) switch(pft2) { case pftEvenOdd: case pftNonZero: return (edge.WindCnt2 == 0); case pftPositive: return (edge.WindCnt2 <= 0); default: return (edge.WindCnt2 >= 0); } else switch(pft2) { case pftEvenOdd: case pftNonZero: return (edge.WindCnt2 != 0); case pftPositive: return (edge.WindCnt2 > 0); default: return (edge.WindCnt2 < 0); } break; case ctXor: if (edge.WindDelta == 0) //XOr always contributing unless open switch(pft2) { case pftEvenOdd: case pftNonZero: return (edge.WindCnt2 == 0); case pftPositive: return (edge.WindCnt2 <= 0); default: return (edge.WindCnt2 >= 0); } else return true; break; default: return true; } } //------------------------------------------------------------------------------ OutPt* Clipper::AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &Pt) { OutPt* result; TEdge *e, *prevE; if (IsHorizontal(*e2) || ( e1->Dx > e2->Dx )) { result = AddOutPt(e1, Pt); e2->OutIdx = e1->OutIdx; e1->Side = esLeft; e2->Side = esRight; e = e1; if (e->PrevInAEL == e2) prevE = e2->PrevInAEL; else prevE = e->PrevInAEL; } else { result = AddOutPt(e2, Pt); e1->OutIdx = e2->OutIdx; e1->Side = esRight; e2->Side = esLeft; e = e2; if (e->PrevInAEL == e1) prevE = e1->PrevInAEL; else prevE = e->PrevInAEL; } if (prevE && prevE->OutIdx >= 0) { cInt xPrev = TopX(*prevE, Pt.Y); cInt xE = TopX(*e, Pt.Y); if (xPrev == xE && (e->WindDelta != 0) && (prevE->WindDelta != 0) && SlopesEqual(IntPoint(xPrev, Pt.Y), prevE->Top, IntPoint(xE, Pt.Y), e->Top, m_UseFullRange)) { OutPt* outPt = AddOutPt(prevE, Pt); AddJoin(result, outPt, e->Top); } } return result; } //------------------------------------------------------------------------------ void Clipper::AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &Pt) { AddOutPt( e1, Pt ); if (e2->WindDelta == 0) AddOutPt(e2, Pt); if( e1->OutIdx == e2->OutIdx ) { e1->OutIdx = Unassigned; e2->OutIdx = Unassigned; } else if (e1->OutIdx < e2->OutIdx) AppendPolygon(e1, e2); else AppendPolygon(e2, e1); } //------------------------------------------------------------------------------ void Clipper::AddEdgeToSEL(TEdge *edge) { //SEL pointers in PEdge are reused to build a list of horizontal edges. //However, we don't need to worry about order with horizontal edge processing. if( !m_SortedEdges ) { m_SortedEdges = edge; edge->PrevInSEL = 0; edge->NextInSEL = 0; } else { edge->NextInSEL = m_SortedEdges; edge->PrevInSEL = 0; m_SortedEdges->PrevInSEL = edge; m_SortedEdges = edge; } } //------------------------------------------------------------------------------ bool Clipper::PopEdgeFromSEL(TEdge *&edge) { if (!m_SortedEdges) return false; edge = m_SortedEdges; DeleteFromSEL(m_SortedEdges); return true; } //------------------------------------------------------------------------------ void Clipper::CopyAELToSEL() { TEdge* e = m_ActiveEdges; m_SortedEdges = e; while ( e ) { e->PrevInSEL = e->PrevInAEL; e->NextInSEL = e->NextInAEL; e = e->NextInAEL; } } //------------------------------------------------------------------------------ void Clipper::AddJoin(OutPt *op1, OutPt *op2, const IntPoint OffPt) { Join* j = new Join; j->OutPt1 = op1; j->OutPt2 = op2; j->OffPt = OffPt; m_Joins.push_back(j); } //------------------------------------------------------------------------------ void Clipper::ClearJoins() { for (JoinList::size_type i = 0; i < m_Joins.size(); i++) delete m_Joins[i]; m_Joins.resize(0); } //------------------------------------------------------------------------------ void Clipper::ClearGhostJoins() { for (JoinList::size_type i = 0; i < m_GhostJoins.size(); i++) delete m_GhostJoins[i]; m_GhostJoins.resize(0); } //------------------------------------------------------------------------------ void Clipper::AddGhostJoin(OutPt *op, const IntPoint OffPt) { Join* j = new Join; j->OutPt1 = op; j->OutPt2 = 0; j->OffPt = OffPt; m_GhostJoins.push_back(j); } //------------------------------------------------------------------------------ void Clipper::InsertLocalMinimaIntoAEL(const cInt botY) { const LocalMinimum *lm; while (PopLocalMinima(botY, lm)) { TEdge* lb = lm->LeftBound; TEdge* rb = lm->RightBound; OutPt *Op1 = 0; if (!lb) { //nb: don't insert LB into either AEL or SEL InsertEdgeIntoAEL(rb, 0); SetWindingCount(*rb); if (IsContributing(*rb)) Op1 = AddOutPt(rb, rb->Bot); } else if (!rb) { InsertEdgeIntoAEL(lb, 0); SetWindingCount(*lb); if (IsContributing(*lb)) Op1 = AddOutPt(lb, lb->Bot); InsertScanbeam(lb->Top.Y); } else { InsertEdgeIntoAEL(lb, 0); InsertEdgeIntoAEL(rb, lb); SetWindingCount( *lb ); rb->WindCnt = lb->WindCnt; rb->WindCnt2 = lb->WindCnt2; if (IsContributing(*lb)) Op1 = AddLocalMinPoly(lb, rb, lb->Bot); InsertScanbeam(lb->Top.Y); } if (rb) { if (IsHorizontal(*rb)) { AddEdgeToSEL(rb); if (rb->NextInLML) InsertScanbeam(rb->NextInLML->Top.Y); } else InsertScanbeam( rb->Top.Y ); } if (!lb || !rb) continue; //if any output polygons share an edge, they'll need joining later ... if (Op1 && IsHorizontal(*rb) && m_GhostJoins.size() > 0 && (rb->WindDelta != 0)) { for (JoinList::size_type i = 0; i < m_GhostJoins.size(); ++i) { Join* jr = m_GhostJoins[i]; //if the horizontal Rb and a 'ghost' horizontal overlap, then convert //the 'ghost' join to a real join ready for later ... if (HorzSegmentsOverlap(jr->OutPt1->Pt.X, jr->OffPt.X, rb->Bot.X, rb->Top.X)) AddJoin(jr->OutPt1, Op1, jr->OffPt); } } if (lb->OutIdx >= 0 && lb->PrevInAEL && lb->PrevInAEL->Curr.X == lb->Bot.X && lb->PrevInAEL->OutIdx >= 0 && SlopesEqual(lb->PrevInAEL->Bot, lb->PrevInAEL->Top, lb->Curr, lb->Top, m_UseFullRange) && (lb->WindDelta != 0) && (lb->PrevInAEL->WindDelta != 0)) { OutPt *Op2 = AddOutPt(lb->PrevInAEL, lb->Bot); AddJoin(Op1, Op2, lb->Top); } if(lb->NextInAEL != rb) { if (rb->OutIdx >= 0 && rb->PrevInAEL->OutIdx >= 0 && SlopesEqual(rb->PrevInAEL->Curr, rb->PrevInAEL->Top, rb->Curr, rb->Top, m_UseFullRange) && (rb->WindDelta != 0) && (rb->PrevInAEL->WindDelta != 0)) { OutPt *Op2 = AddOutPt(rb->PrevInAEL, rb->Bot); AddJoin(Op1, Op2, rb->Top); } TEdge* e = lb->NextInAEL; if (e) { while( e != rb ) { //nb: For calculating winding counts etc, IntersectEdges() assumes //that param1 will be to the Right of param2 ABOVE the intersection ... IntersectEdges(rb , e , lb->Curr); //order important here e = e->NextInAEL; } } } } } //------------------------------------------------------------------------------ void Clipper::DeleteFromSEL(TEdge *e) { TEdge* SelPrev = e->PrevInSEL; TEdge* SelNext = e->NextInSEL; if( !SelPrev && !SelNext && (e != m_SortedEdges) ) return; //already deleted if( SelPrev ) SelPrev->NextInSEL = SelNext; else m_SortedEdges = SelNext; if( SelNext ) SelNext->PrevInSEL = SelPrev; e->NextInSEL = 0; e->PrevInSEL = 0; } //------------------------------------------------------------------------------ #ifdef use_xyz void Clipper::SetZ(IntPoint& pt, TEdge& e1, TEdge& e2) { if (pt.Z != 0 || !m_ZFill) return; else if (pt == e1.Bot) pt.Z = e1.Bot.Z; else if (pt == e1.Top) pt.Z = e1.Top.Z; else if (pt == e2.Bot) pt.Z = e2.Bot.Z; else if (pt == e2.Top) pt.Z = e2.Top.Z; else (*m_ZFill)(e1.Bot, e1.Top, e2.Bot, e2.Top, pt); } //------------------------------------------------------------------------------ #endif void Clipper::IntersectEdges(TEdge *e1, TEdge *e2, IntPoint &Pt) { bool e1Contributing = ( e1->OutIdx >= 0 ); bool e2Contributing = ( e2->OutIdx >= 0 ); #ifdef use_xyz SetZ(Pt, *e1, *e2); #endif #ifdef use_lines //if either edge is on an OPEN path ... if (e1->WindDelta == 0 || e2->WindDelta == 0) { //ignore subject-subject open path intersections UNLESS they //are both open paths, AND they are both 'contributing maximas' ... if (e1->WindDelta == 0 && e2->WindDelta == 0) return; //if intersecting a subj line with a subj poly ... else if (e1->PolyTyp == e2->PolyTyp && e1->WindDelta != e2->WindDelta && m_ClipType == ctUnion) { if (e1->WindDelta == 0) { if (e2Contributing) { AddOutPt(e1, Pt); if (e1Contributing) e1->OutIdx = Unassigned; } } else { if (e1Contributing) { AddOutPt(e2, Pt); if (e2Contributing) e2->OutIdx = Unassigned; } } } else if (e1->PolyTyp != e2->PolyTyp) { //toggle subj open path OutIdx on/off when Abs(clip.WndCnt) == 1 ... if ((e1->WindDelta == 0) && abs(e2->WindCnt) == 1 && (m_ClipType != ctUnion || e2->WindCnt2 == 0)) { AddOutPt(e1, Pt); if (e1Contributing) e1->OutIdx = Unassigned; } else if ((e2->WindDelta == 0) && (abs(e1->WindCnt) == 1) && (m_ClipType != ctUnion || e1->WindCnt2 == 0)) { AddOutPt(e2, Pt); if (e2Contributing) e2->OutIdx = Unassigned; } } return; } #endif //update winding counts... //assumes that e1 will be to the Right of e2 ABOVE the intersection if ( e1->PolyTyp == e2->PolyTyp ) { if ( IsEvenOddFillType( *e1) ) { int oldE1WindCnt = e1->WindCnt; e1->WindCnt = e2->WindCnt; e2->WindCnt = oldE1WindCnt; } else { if (e1->WindCnt + e2->WindDelta == 0 ) e1->WindCnt = -e1->WindCnt; else e1->WindCnt += e2->WindDelta; if ( e2->WindCnt - e1->WindDelta == 0 ) e2->WindCnt = -e2->WindCnt; else e2->WindCnt -= e1->WindDelta; } } else { if (!IsEvenOddFillType(*e2)) e1->WindCnt2 += e2->WindDelta; else e1->WindCnt2 = ( e1->WindCnt2 == 0 ) ? 1 : 0; if (!IsEvenOddFillType(*e1)) e2->WindCnt2 -= e1->WindDelta; else e2->WindCnt2 = ( e2->WindCnt2 == 0 ) ? 1 : 0; } PolyFillType e1FillType, e2FillType, e1FillType2, e2FillType2; if (e1->PolyTyp == ptSubject) { e1FillType = m_SubjFillType; e1FillType2 = m_ClipFillType; } else { e1FillType = m_ClipFillType; e1FillType2 = m_SubjFillType; } if (e2->PolyTyp == ptSubject) { e2FillType = m_SubjFillType; e2FillType2 = m_ClipFillType; } else { e2FillType = m_ClipFillType; e2FillType2 = m_SubjFillType; } cInt e1Wc, e2Wc; switch (e1FillType) { case pftPositive: e1Wc = e1->WindCnt; break; case pftNegative: e1Wc = -e1->WindCnt; break; default: e1Wc = Abs(e1->WindCnt); } switch(e2FillType) { case pftPositive: e2Wc = e2->WindCnt; break; case pftNegative: e2Wc = -e2->WindCnt; break; default: e2Wc = Abs(e2->WindCnt); } if ( e1Contributing && e2Contributing ) { if ((e1Wc != 0 && e1Wc != 1) || (e2Wc != 0 && e2Wc != 1) || (e1->PolyTyp != e2->PolyTyp && m_ClipType != ctXor) ) { AddLocalMaxPoly(e1, e2, Pt); } else { AddOutPt(e1, Pt); AddOutPt(e2, Pt); SwapSides( *e1 , *e2 ); SwapPolyIndexes( *e1 , *e2 ); } } else if ( e1Contributing ) { if (e2Wc == 0 || e2Wc == 1) { AddOutPt(e1, Pt); SwapSides(*e1, *e2); SwapPolyIndexes(*e1, *e2); } } else if ( e2Contributing ) { if (e1Wc == 0 || e1Wc == 1) { AddOutPt(e2, Pt); SwapSides(*e1, *e2); SwapPolyIndexes(*e1, *e2); } } else if ( (e1Wc == 0 || e1Wc == 1) && (e2Wc == 0 || e2Wc == 1)) { //neither edge is currently contributing ... cInt e1Wc2, e2Wc2; switch (e1FillType2) { case pftPositive: e1Wc2 = e1->WindCnt2; break; case pftNegative : e1Wc2 = -e1->WindCnt2; break; default: e1Wc2 = Abs(e1->WindCnt2); } switch (e2FillType2) { case pftPositive: e2Wc2 = e2->WindCnt2; break; case pftNegative: e2Wc2 = -e2->WindCnt2; break; default: e2Wc2 = Abs(e2->WindCnt2); } if (e1->PolyTyp != e2->PolyTyp) { AddLocalMinPoly(e1, e2, Pt); } else if (e1Wc == 1 && e2Wc == 1) switch( m_ClipType ) { case ctIntersection: if (e1Wc2 > 0 && e2Wc2 > 0) AddLocalMinPoly(e1, e2, Pt); break; case ctUnion: if ( e1Wc2 <= 0 && e2Wc2 <= 0 ) AddLocalMinPoly(e1, e2, Pt); break; case ctDifference: if (((e1->PolyTyp == ptClip) && (e1Wc2 > 0) && (e2Wc2 > 0)) || ((e1->PolyTyp == ptSubject) && (e1Wc2 <= 0) && (e2Wc2 <= 0))) AddLocalMinPoly(e1, e2, Pt); break; case ctXor: AddLocalMinPoly(e1, e2, Pt); } else SwapSides( *e1, *e2 ); } } //------------------------------------------------------------------------------ void Clipper::SetHoleState(TEdge *e, OutRec *outrec) { TEdge *e2 = e->PrevInAEL; TEdge *eTmp = 0; while (e2) { if (e2->OutIdx >= 0 && e2->WindDelta != 0) { if (!eTmp) eTmp = e2; else if (eTmp->OutIdx == e2->OutIdx) eTmp = 0; } e2 = e2->PrevInAEL; } if (!eTmp) { outrec->FirstLeft = 0; outrec->IsHole = false; } else { outrec->FirstLeft = m_PolyOuts[eTmp->OutIdx]; outrec->IsHole = !outrec->FirstLeft->IsHole; } } //------------------------------------------------------------------------------ OutRec* GetLowermostRec(OutRec *outRec1, OutRec *outRec2) { //work out which polygon fragment has the correct hole state ... if (!outRec1->BottomPt) outRec1->BottomPt = GetBottomPt(outRec1->Pts); if (!outRec2->BottomPt) outRec2->BottomPt = GetBottomPt(outRec2->Pts); OutPt *OutPt1 = outRec1->BottomPt; OutPt *OutPt2 = outRec2->BottomPt; if (OutPt1->Pt.Y > OutPt2->Pt.Y) return outRec1; else if (OutPt1->Pt.Y < OutPt2->Pt.Y) return outRec2; else if (OutPt1->Pt.X < OutPt2->Pt.X) return outRec1; else if (OutPt1->Pt.X > OutPt2->Pt.X) return outRec2; else if (OutPt1->Next == OutPt1) return outRec2; else if (OutPt2->Next == OutPt2) return outRec1; else if (FirstIsBottomPt(OutPt1, OutPt2)) return outRec1; else return outRec2; } //------------------------------------------------------------------------------ bool OutRec1RightOfOutRec2(OutRec* outRec1, OutRec* outRec2) { do { outRec1 = outRec1->FirstLeft; if (outRec1 == outRec2) return true; } while (outRec1); return false; } //------------------------------------------------------------------------------ OutRec* Clipper::GetOutRec(int Idx) { OutRec* outrec = m_PolyOuts[Idx]; while (outrec != m_PolyOuts[outrec->Idx]) outrec = m_PolyOuts[outrec->Idx]; return outrec; } //------------------------------------------------------------------------------ void Clipper::AppendPolygon(TEdge *e1, TEdge *e2) { //get the start and ends of both output polygons ... OutRec *outRec1 = m_PolyOuts[e1->OutIdx]; OutRec *outRec2 = m_PolyOuts[e2->OutIdx]; OutRec *holeStateRec; if (OutRec1RightOfOutRec2(outRec1, outRec2)) holeStateRec = outRec2; else if (OutRec1RightOfOutRec2(outRec2, outRec1)) holeStateRec = outRec1; else holeStateRec = GetLowermostRec(outRec1, outRec2); //get the start and ends of both output polygons and //join e2 poly onto e1 poly and delete pointers to e2 ... OutPt* p1_lft = outRec1->Pts; OutPt* p1_rt = p1_lft->Prev; OutPt* p2_lft = outRec2->Pts; OutPt* p2_rt = p2_lft->Prev; //join e2 poly onto e1 poly and delete pointers to e2 ... if( e1->Side == esLeft ) { if( e2->Side == esLeft ) { //z y x a b c ReversePolyPtLinks(p2_lft); p2_lft->Next = p1_lft; p1_lft->Prev = p2_lft; p1_rt->Next = p2_rt; p2_rt->Prev = p1_rt; outRec1->Pts = p2_rt; } else { //x y z a b c p2_rt->Next = p1_lft; p1_lft->Prev = p2_rt; p2_lft->Prev = p1_rt; p1_rt->Next = p2_lft; outRec1->Pts = p2_lft; } } else { if( e2->Side == esRight ) { //a b c z y x ReversePolyPtLinks(p2_lft); p1_rt->Next = p2_rt; p2_rt->Prev = p1_rt; p2_lft->Next = p1_lft; p1_lft->Prev = p2_lft; } else { //a b c x y z p1_rt->Next = p2_lft; p2_lft->Prev = p1_rt; p1_lft->Prev = p2_rt; p2_rt->Next = p1_lft; } } outRec1->BottomPt = 0; if (holeStateRec == outRec2) { if (outRec2->FirstLeft != outRec1) outRec1->FirstLeft = outRec2->FirstLeft; outRec1->IsHole = outRec2->IsHole; } outRec2->Pts = 0; outRec2->BottomPt = 0; outRec2->FirstLeft = outRec1; int OKIdx = e1->OutIdx; int ObsoleteIdx = e2->OutIdx; e1->OutIdx = Unassigned; //nb: safe because we only get here via AddLocalMaxPoly e2->OutIdx = Unassigned; TEdge* e = m_ActiveEdges; while( e ) { if( e->OutIdx == ObsoleteIdx ) { e->OutIdx = OKIdx; e->Side = e1->Side; break; } e = e->NextInAEL; } outRec2->Idx = outRec1->Idx; } //------------------------------------------------------------------------------ OutPt* Clipper::AddOutPt(TEdge *e, const IntPoint &pt) { if( e->OutIdx < 0 ) { OutRec *outRec = CreateOutRec(); outRec->IsOpen = (e->WindDelta == 0); OutPt* newOp = new OutPt; outRec->Pts = newOp; newOp->Idx = outRec->Idx; newOp->Pt = pt; newOp->Next = newOp; newOp->Prev = newOp; if (!outRec->IsOpen) SetHoleState(e, outRec); e->OutIdx = outRec->Idx; return newOp; } else { OutRec *outRec = m_PolyOuts[e->OutIdx]; //OutRec.Pts is the 'Left-most' point & OutRec.Pts.Prev is the 'Right-most' OutPt* op = outRec->Pts; bool ToFront = (e->Side == esLeft); if (ToFront && (pt == op->Pt)) return op; else if (!ToFront && (pt == op->Prev->Pt)) return op->Prev; OutPt* newOp = new OutPt; newOp->Idx = outRec->Idx; newOp->Pt = pt; newOp->Next = op; newOp->Prev = op->Prev; newOp->Prev->Next = newOp; op->Prev = newOp; if (ToFront) outRec->Pts = newOp; return newOp; } } //------------------------------------------------------------------------------ OutPt* Clipper::GetLastOutPt(TEdge *e) { OutRec *outRec = m_PolyOuts[e->OutIdx]; if (e->Side == esLeft) return outRec->Pts; else return outRec->Pts->Prev; } //------------------------------------------------------------------------------ void Clipper::ProcessHorizontals() { TEdge* horzEdge; while (PopEdgeFromSEL(horzEdge)) ProcessHorizontal(horzEdge); } //------------------------------------------------------------------------------ inline bool IsMinima(TEdge *e) { return e && (e->Prev->NextInLML != e) && (e->Next->NextInLML != e); } //------------------------------------------------------------------------------ inline bool IsMaxima(TEdge *e, const cInt Y) { return e && e->Top.Y == Y && !e->NextInLML; } //------------------------------------------------------------------------------ inline bool IsIntermediate(TEdge *e, const cInt Y) { return e->Top.Y == Y && e->NextInLML; } //------------------------------------------------------------------------------ TEdge *GetMaximaPair(TEdge *e) { if ((e->Next->Top == e->Top) && !e->Next->NextInLML) return e->Next; else if ((e->Prev->Top == e->Top) && !e->Prev->NextInLML) return e->Prev; else return 0; } //------------------------------------------------------------------------------ TEdge *GetMaximaPairEx(TEdge *e) { //as GetMaximaPair() but returns 0 if MaxPair isn't in AEL (unless it's horizontal) TEdge* result = GetMaximaPair(e); if (result && (result->OutIdx == Skip || (result->NextInAEL == result->PrevInAEL && !IsHorizontal(*result)))) return 0; return result; } //------------------------------------------------------------------------------ void Clipper::SwapPositionsInSEL(TEdge *Edge1, TEdge *Edge2) { if( !( Edge1->NextInSEL ) && !( Edge1->PrevInSEL ) ) return; if( !( Edge2->NextInSEL ) && !( Edge2->PrevInSEL ) ) return; if( Edge1->NextInSEL == Edge2 ) { TEdge* Next = Edge2->NextInSEL; if( Next ) Next->PrevInSEL = Edge1; TEdge* Prev = Edge1->PrevInSEL; if( Prev ) Prev->NextInSEL = Edge2; Edge2->PrevInSEL = Prev; Edge2->NextInSEL = Edge1; Edge1->PrevInSEL = Edge2; Edge1->NextInSEL = Next; } else if( Edge2->NextInSEL == Edge1 ) { TEdge* Next = Edge1->NextInSEL; if( Next ) Next->PrevInSEL = Edge2; TEdge* Prev = Edge2->PrevInSEL; if( Prev ) Prev->NextInSEL = Edge1; Edge1->PrevInSEL = Prev; Edge1->NextInSEL = Edge2; Edge2->PrevInSEL = Edge1; Edge2->NextInSEL = Next; } else { TEdge* Next = Edge1->NextInSEL; TEdge* Prev = Edge1->PrevInSEL; Edge1->NextInSEL = Edge2->NextInSEL; if( Edge1->NextInSEL ) Edge1->NextInSEL->PrevInSEL = Edge1; Edge1->PrevInSEL = Edge2->PrevInSEL; if( Edge1->PrevInSEL ) Edge1->PrevInSEL->NextInSEL = Edge1; Edge2->NextInSEL = Next; if( Edge2->NextInSEL ) Edge2->NextInSEL->PrevInSEL = Edge2; Edge2->PrevInSEL = Prev; if( Edge2->PrevInSEL ) Edge2->PrevInSEL->NextInSEL = Edge2; } if( !Edge1->PrevInSEL ) m_SortedEdges = Edge1; else if( !Edge2->PrevInSEL ) m_SortedEdges = Edge2; } //------------------------------------------------------------------------------ TEdge* GetNextInAEL(TEdge *e, Direction dir) { return dir == dLeftToRight ? e->NextInAEL : e->PrevInAEL; } //------------------------------------------------------------------------------ void GetHorzDirection(TEdge& HorzEdge, Direction& Dir, cInt& Left, cInt& Right) { if (HorzEdge.Bot.X < HorzEdge.Top.X) { Left = HorzEdge.Bot.X; Right = HorzEdge.Top.X; Dir = dLeftToRight; } else { Left = HorzEdge.Top.X; Right = HorzEdge.Bot.X; Dir = dRightToLeft; } } //------------------------------------------------------------------------ /******************************************************************************* * Notes: Horizontal edges (HEs) at scanline intersections (ie at the Top or * * Bottom of a scanbeam) are processed as if layered. The order in which HEs * * are processed doesn't matter. HEs intersect with other HE Bot.Xs only [#] * * (or they could intersect with Top.Xs only, ie EITHER Bot.Xs OR Top.Xs), * * and with other non-horizontal edges [*]. Once these intersections are * * processed, intermediate HEs then 'promote' the Edge above (NextInLML) into * * the AEL. These 'promoted' edges may in turn intersect [%] with other HEs. * *******************************************************************************/ void Clipper::ProcessHorizontal(TEdge *horzEdge) { Direction dir; cInt horzLeft, horzRight; bool IsOpen = (horzEdge->WindDelta == 0); GetHorzDirection(*horzEdge, dir, horzLeft, horzRight); TEdge* eLastHorz = horzEdge, *eMaxPair = 0; while (eLastHorz->NextInLML && IsHorizontal(*eLastHorz->NextInLML)) eLastHorz = eLastHorz->NextInLML; if (!eLastHorz->NextInLML) eMaxPair = GetMaximaPair(eLastHorz); MaximaList::const_iterator maxIt; MaximaList::const_reverse_iterator maxRit; if (m_Maxima.size() > 0) { //get the first maxima in range (X) ... if (dir == dLeftToRight) { maxIt = m_Maxima.begin(); while (maxIt != m_Maxima.end() && *maxIt <= horzEdge->Bot.X) maxIt++; if (maxIt != m_Maxima.end() && *maxIt >= eLastHorz->Top.X) maxIt = m_Maxima.end(); } else { maxRit = m_Maxima.rbegin(); while (maxRit != m_Maxima.rend() && *maxRit > horzEdge->Bot.X) maxRit++; if (maxRit != m_Maxima.rend() && *maxRit <= eLastHorz->Top.X) maxRit = m_Maxima.rend(); } } OutPt* op1 = 0; for (;;) //loop through consec. horizontal edges { bool IsLastHorz = (horzEdge == eLastHorz); TEdge* e = GetNextInAEL(horzEdge, dir); while(e) { //this code block inserts extra coords into horizontal edges (in output //polygons) whereever maxima touch these horizontal edges. This helps //'simplifying' polygons (ie if the Simplify property is set). if (m_Maxima.size() > 0) { if (dir == dLeftToRight) { while (maxIt != m_Maxima.end() && *maxIt < e->Curr.X) { if (horzEdge->OutIdx >= 0 && !IsOpen) AddOutPt(horzEdge, IntPoint(*maxIt, horzEdge->Bot.Y)); maxIt++; } } else { while (maxRit != m_Maxima.rend() && *maxRit > e->Curr.X) { if (horzEdge->OutIdx >= 0 && !IsOpen) AddOutPt(horzEdge, IntPoint(*maxRit, horzEdge->Bot.Y)); maxRit++; } } }; if ((dir == dLeftToRight && e->Curr.X > horzRight) || (dir == dRightToLeft && e->Curr.X < horzLeft)) break; //Also break if we've got to the end of an intermediate horizontal edge ... //nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal. if (e->Curr.X == horzEdge->Top.X && horzEdge->NextInLML && e->Dx < horzEdge->NextInLML->Dx) break; if (horzEdge->OutIdx >= 0 && !IsOpen) //note: may be done multiple times { op1 = AddOutPt(horzEdge, e->Curr); TEdge* eNextHorz = m_SortedEdges; while (eNextHorz) { if (eNextHorz->OutIdx >= 0 && HorzSegmentsOverlap(horzEdge->Bot.X, horzEdge->Top.X, eNextHorz->Bot.X, eNextHorz->Top.X)) { OutPt* op2 = GetLastOutPt(eNextHorz); AddJoin(op2, op1, eNextHorz->Top); } eNextHorz = eNextHorz->NextInSEL; } AddGhostJoin(op1, horzEdge->Bot); } //OK, so far we're still in range of the horizontal Edge but make sure //we're at the last of consec. horizontals when matching with eMaxPair if(e == eMaxPair && IsLastHorz) { if (horzEdge->OutIdx >= 0) AddLocalMaxPoly(horzEdge, eMaxPair, horzEdge->Top); DeleteFromAEL(horzEdge); DeleteFromAEL(eMaxPair); return; } if(dir == dLeftToRight) { IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y); IntersectEdges(horzEdge, e, Pt); } else { IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y); IntersectEdges( e, horzEdge, Pt); } TEdge* eNext = GetNextInAEL(e, dir); SwapPositionsInAEL( horzEdge, e ); e = eNext; } //end while(e) //Break out of loop if HorzEdge.NextInLML is not also horizontal ... if (!horzEdge->NextInLML || !IsHorizontal(*horzEdge->NextInLML)) break; UpdateEdgeIntoAEL(horzEdge); if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Bot); GetHorzDirection(*horzEdge, dir, horzLeft, horzRight); } //end for (;;) if (horzEdge->OutIdx >= 0 && !op1) { op1 = GetLastOutPt(horzEdge); TEdge* eNextHorz = m_SortedEdges; while (eNextHorz) { if (eNextHorz->OutIdx >= 0 && HorzSegmentsOverlap(horzEdge->Bot.X, horzEdge->Top.X, eNextHorz->Bot.X, eNextHorz->Top.X)) { OutPt* op2 = GetLastOutPt(eNextHorz); AddJoin(op2, op1, eNextHorz->Top); } eNextHorz = eNextHorz->NextInSEL; } AddGhostJoin(op1, horzEdge->Top); } if (horzEdge->NextInLML) { if(horzEdge->OutIdx >= 0) { op1 = AddOutPt( horzEdge, horzEdge->Top); UpdateEdgeIntoAEL(horzEdge); if (horzEdge->WindDelta == 0) return; //nb: HorzEdge is no longer horizontal here TEdge* ePrev = horzEdge->PrevInAEL; TEdge* eNext = horzEdge->NextInAEL; if (ePrev && ePrev->Curr.X == horzEdge->Bot.X && ePrev->Curr.Y == horzEdge->Bot.Y && ePrev->WindDelta != 0 && (ePrev->OutIdx >= 0 && ePrev->Curr.Y > ePrev->Top.Y && SlopesEqual(*horzEdge, *ePrev, m_UseFullRange))) { OutPt* op2 = AddOutPt(ePrev, horzEdge->Bot); AddJoin(op1, op2, horzEdge->Top); } else if (eNext && eNext->Curr.X == horzEdge->Bot.X && eNext->Curr.Y == horzEdge->Bot.Y && eNext->WindDelta != 0 && eNext->OutIdx >= 0 && eNext->Curr.Y > eNext->Top.Y && SlopesEqual(*horzEdge, *eNext, m_UseFullRange)) { OutPt* op2 = AddOutPt(eNext, horzEdge->Bot); AddJoin(op1, op2, horzEdge->Top); } } else UpdateEdgeIntoAEL(horzEdge); } else { if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Top); DeleteFromAEL(horzEdge); } } //------------------------------------------------------------------------------ bool Clipper::ProcessIntersections(const cInt topY) { if( !m_ActiveEdges ) return true; try { BuildIntersectList(topY); size_t IlSize = m_IntersectList.size(); if (IlSize == 0) return true; if (IlSize == 1 || FixupIntersectionOrder()) ProcessIntersectList(); else return false; } catch(...) { m_SortedEdges = 0; DisposeIntersectNodes(); throw clipperException("ProcessIntersections error"); } m_SortedEdges = 0; return true; } //------------------------------------------------------------------------------ void Clipper::DisposeIntersectNodes() { for (size_t i = 0; i < m_IntersectList.size(); ++i ) delete m_IntersectList[i]; m_IntersectList.clear(); } //------------------------------------------------------------------------------ void Clipper::BuildIntersectList(const cInt topY) { if ( !m_ActiveEdges ) return; //prepare for sorting ... TEdge* e = m_ActiveEdges; m_SortedEdges = e; while( e ) { e->PrevInSEL = e->PrevInAEL; e->NextInSEL = e->NextInAEL; e->Curr.X = TopX( *e, topY ); e = e->NextInAEL; } //bubblesort ... bool isModified; do { isModified = false; e = m_SortedEdges; while( e->NextInSEL ) { TEdge *eNext = e->NextInSEL; IntPoint Pt; if(e->Curr.X > eNext->Curr.X) { IntersectPoint(*e, *eNext, Pt); if (Pt.Y < topY) Pt = IntPoint(TopX(*e, topY), topY); IntersectNode * newNode = new IntersectNode; newNode->Edge1 = e; newNode->Edge2 = eNext; newNode->Pt = Pt; m_IntersectList.push_back(newNode); SwapPositionsInSEL(e, eNext); isModified = true; } else e = eNext; } if( e->PrevInSEL ) e->PrevInSEL->NextInSEL = 0; else break; } while ( isModified ); m_SortedEdges = 0; //important } //------------------------------------------------------------------------------ void Clipper::ProcessIntersectList() { for (size_t i = 0; i < m_IntersectList.size(); ++i) { IntersectNode* iNode = m_IntersectList[i]; { IntersectEdges( iNode->Edge1, iNode->Edge2, iNode->Pt); SwapPositionsInAEL( iNode->Edge1 , iNode->Edge2 ); } delete iNode; } m_IntersectList.clear(); } //------------------------------------------------------------------------------ bool IntersectListSort(IntersectNode* node1, IntersectNode* node2) { return node2->Pt.Y < node1->Pt.Y; } //------------------------------------------------------------------------------ inline bool EdgesAdjacent(const IntersectNode &inode) { return (inode.Edge1->NextInSEL == inode.Edge2) || (inode.Edge1->PrevInSEL == inode.Edge2); } //------------------------------------------------------------------------------ bool Clipper::FixupIntersectionOrder() { //pre-condition: intersections are sorted Bottom-most first. //Now it's crucial that intersections are made only between adjacent edges, //so to ensure this the order of intersections may need adjusting ... CopyAELToSEL(); std::sort(m_IntersectList.begin(), m_IntersectList.end(), IntersectListSort); size_t cnt = m_IntersectList.size(); for (size_t i = 0; i < cnt; ++i) { if (!EdgesAdjacent(*m_IntersectList[i])) { size_t j = i + 1; while (j < cnt && !EdgesAdjacent(*m_IntersectList[j])) j++; if (j == cnt) return false; std::swap(m_IntersectList[i], m_IntersectList[j]); } SwapPositionsInSEL(m_IntersectList[i]->Edge1, m_IntersectList[i]->Edge2); } return true; } //------------------------------------------------------------------------------ void Clipper::DoMaxima(TEdge *e) { TEdge* eMaxPair = GetMaximaPairEx(e); if (!eMaxPair) { if (e->OutIdx >= 0) AddOutPt(e, e->Top); DeleteFromAEL(e); return; } TEdge* eNext = e->NextInAEL; while(eNext && eNext != eMaxPair) { IntersectEdges(e, eNext, e->Top); SwapPositionsInAEL(e, eNext); eNext = e->NextInAEL; } if(e->OutIdx == Unassigned && eMaxPair->OutIdx == Unassigned) { DeleteFromAEL(e); DeleteFromAEL(eMaxPair); } else if( e->OutIdx >= 0 && eMaxPair->OutIdx >= 0 ) { if (e->OutIdx >= 0) AddLocalMaxPoly(e, eMaxPair, e->Top); DeleteFromAEL(e); DeleteFromAEL(eMaxPair); } #ifdef use_lines else if (e->WindDelta == 0) { if (e->OutIdx >= 0) { AddOutPt(e, e->Top); e->OutIdx = Unassigned; } DeleteFromAEL(e); if (eMaxPair->OutIdx >= 0) { AddOutPt(eMaxPair, e->Top); eMaxPair->OutIdx = Unassigned; } DeleteFromAEL(eMaxPair); } #endif else throw clipperException("DoMaxima error"); } //------------------------------------------------------------------------------ void Clipper::ProcessEdgesAtTopOfScanbeam(const cInt topY) { TEdge* e = m_ActiveEdges; while( e ) { //1. process maxima, treating them as if they're 'bent' horizontal edges, // but exclude maxima with horizontal edges. nb: e can't be a horizontal. bool IsMaximaEdge = IsMaxima(e, topY); if(IsMaximaEdge) { TEdge* eMaxPair = GetMaximaPairEx(e); IsMaximaEdge = (!eMaxPair || !IsHorizontal(*eMaxPair)); } if(IsMaximaEdge) { if (m_StrictSimple) m_Maxima.push_back(e->Top.X); TEdge* ePrev = e->PrevInAEL; DoMaxima(e); if( !ePrev ) e = m_ActiveEdges; else e = ePrev->NextInAEL; } else { //2. promote horizontal edges, otherwise update Curr.X and Curr.Y ... if (IsIntermediate(e, topY) && IsHorizontal(*e->NextInLML)) { UpdateEdgeIntoAEL(e); if (e->OutIdx >= 0) AddOutPt(e, e->Bot); AddEdgeToSEL(e); } else { e->Curr.X = TopX( *e, topY ); e->Curr.Y = topY; } //When StrictlySimple and 'e' is being touched by another edge, then //make sure both edges have a vertex here ... if (m_StrictSimple) { TEdge* ePrev = e->PrevInAEL; if ((e->OutIdx >= 0) && (e->WindDelta != 0) && ePrev && (ePrev->OutIdx >= 0) && (ePrev->Curr.X == e->Curr.X) && (ePrev->WindDelta != 0)) { IntPoint pt = e->Curr; #ifdef use_xyz SetZ(pt, *ePrev, *e); #endif OutPt* op = AddOutPt(ePrev, pt); OutPt* op2 = AddOutPt(e, pt); AddJoin(op, op2, pt); //StrictlySimple (type-3) join } } e = e->NextInAEL; } } //3. Process horizontals at the Top of the scanbeam ... m_Maxima.sort(); ProcessHorizontals(); m_Maxima.clear(); //4. Promote intermediate vertices ... e = m_ActiveEdges; while(e) { if(IsIntermediate(e, topY)) { OutPt* op = 0; if( e->OutIdx >= 0 ) op = AddOutPt(e, e->Top); UpdateEdgeIntoAEL(e); //if output polygons share an edge, they'll need joining later ... TEdge* ePrev = e->PrevInAEL; TEdge* eNext = e->NextInAEL; if (ePrev && ePrev->Curr.X == e->Bot.X && ePrev->Curr.Y == e->Bot.Y && op && ePrev->OutIdx >= 0 && ePrev->Curr.Y > ePrev->Top.Y && SlopesEqual(e->Curr, e->Top, ePrev->Curr, ePrev->Top, m_UseFullRange) && (e->WindDelta != 0) && (ePrev->WindDelta != 0)) { OutPt* op2 = AddOutPt(ePrev, e->Bot); AddJoin(op, op2, e->Top); } else if (eNext && eNext->Curr.X == e->Bot.X && eNext->Curr.Y == e->Bot.Y && op && eNext->OutIdx >= 0 && eNext->Curr.Y > eNext->Top.Y && SlopesEqual(e->Curr, e->Top, eNext->Curr, eNext->Top, m_UseFullRange) && (e->WindDelta != 0) && (eNext->WindDelta != 0)) { OutPt* op2 = AddOutPt(eNext, e->Bot); AddJoin(op, op2, e->Top); } } e = e->NextInAEL; } } //------------------------------------------------------------------------------ void Clipper::FixupOutPolyline(OutRec &outrec) { OutPt *pp = outrec.Pts; OutPt *lastPP = pp->Prev; while (pp != lastPP) { pp = pp->Next; if (pp->Pt == pp->Prev->Pt) { if (pp == lastPP) lastPP = pp->Prev; OutPt *tmpPP = pp->Prev; tmpPP->Next = pp->Next; pp->Next->Prev = tmpPP; delete pp; pp = tmpPP; } } if (pp == pp->Prev) { DisposeOutPts(pp); outrec.Pts = 0; return; } } //------------------------------------------------------------------------------ void Clipper::FixupOutPolygon(OutRec &outrec) { //FixupOutPolygon() - removes duplicate points and simplifies consecutive //parallel edges by removing the middle vertex. OutPt *lastOK = 0; outrec.BottomPt = 0; OutPt *pp = outrec.Pts; bool preserveCol = m_PreserveCollinear || m_StrictSimple; for (;;) { if (pp->Prev == pp || pp->Prev == pp->Next) { DisposeOutPts(pp); outrec.Pts = 0; return; } //test for duplicate points and collinear edges ... if ((pp->Pt == pp->Next->Pt) || (pp->Pt == pp->Prev->Pt) || (SlopesEqual(pp->Prev->Pt, pp->Pt, pp->Next->Pt, m_UseFullRange) && (!preserveCol || !Pt2IsBetweenPt1AndPt3(pp->Prev->Pt, pp->Pt, pp->Next->Pt)))) { lastOK = 0; OutPt *tmp = pp; pp->Prev->Next = pp->Next; pp->Next->Prev = pp->Prev; pp = pp->Prev; delete tmp; } else if (pp == lastOK) break; else { if (!lastOK) lastOK = pp; pp = pp->Next; } } outrec.Pts = pp; } //------------------------------------------------------------------------------ int PointCount(OutPt *Pts) { if (!Pts) return 0; int result = 0; OutPt* p = Pts; do { result++; p = p->Next; } while (p != Pts); return result; } //------------------------------------------------------------------------------ void Clipper::BuildResult(Paths &polys) { polys.reserve(m_PolyOuts.size()); for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i) { if (!m_PolyOuts[i]->Pts) continue; Path pg; OutPt* p = m_PolyOuts[i]->Pts->Prev; int cnt = PointCount(p); if (cnt < 2) continue; pg.reserve(cnt); for (int i = 0; i < cnt; ++i) { pg.push_back(p->Pt); p = p->Prev; } polys.push_back(pg); } } //------------------------------------------------------------------------------ void Clipper::BuildResult2(PolyTree& polytree) { polytree.Clear(); polytree.AllNodes.reserve(m_PolyOuts.size()); //add each output polygon/contour to polytree ... for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); i++) { OutRec* outRec = m_PolyOuts[i]; int cnt = PointCount(outRec->Pts); if ((outRec->IsOpen && cnt < 2) || (!outRec->IsOpen && cnt < 3)) continue; FixHoleLinkage(*outRec); PolyNode* pn = new PolyNode(); //nb: polytree takes ownership of all the PolyNodes polytree.AllNodes.push_back(pn); outRec->PolyNd = pn; pn->Parent = 0; pn->Index = 0; pn->Contour.reserve(cnt); OutPt *op = outRec->Pts->Prev; for (int j = 0; j < cnt; j++) { pn->Contour.push_back(op->Pt); op = op->Prev; } } //fixup PolyNode links etc ... polytree.Childs.reserve(m_PolyOuts.size()); for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); i++) { OutRec* outRec = m_PolyOuts[i]; if (!outRec->PolyNd) continue; if (outRec->IsOpen) { outRec->PolyNd->m_IsOpen = true; polytree.AddChild(*outRec->PolyNd); } else if (outRec->FirstLeft && outRec->FirstLeft->PolyNd) outRec->FirstLeft->PolyNd->AddChild(*outRec->PolyNd); else polytree.AddChild(*outRec->PolyNd); } } //------------------------------------------------------------------------------ void SwapIntersectNodes(IntersectNode &int1, IntersectNode &int2) { //just swap the contents (because fIntersectNodes is a single-linked-list) IntersectNode inode = int1; //gets a copy of Int1 int1.Edge1 = int2.Edge1; int1.Edge2 = int2.Edge2; int1.Pt = int2.Pt; int2.Edge1 = inode.Edge1; int2.Edge2 = inode.Edge2; int2.Pt = inode.Pt; } //------------------------------------------------------------------------------ inline bool E2InsertsBeforeE1(TEdge &e1, TEdge &e2) { if (e2.Curr.X == e1.Curr.X) { if (e2.Top.Y > e1.Top.Y) return e2.Top.X < TopX(e1, e2.Top.Y); else return e1.Top.X > TopX(e2, e1.Top.Y); } else return e2.Curr.X < e1.Curr.X; } //------------------------------------------------------------------------------ bool GetOverlap(const cInt a1, const cInt a2, const cInt b1, const cInt b2, cInt& Left, cInt& Right) { if (a1 < a2) { if (b1 < b2) {Left = std::max(a1,b1); Right = std::min(a2,b2);} else {Left = std::max(a1,b2); Right = std::min(a2,b1);} } else { if (b1 < b2) {Left = std::max(a2,b1); Right = std::min(a1,b2);} else {Left = std::max(a2,b2); Right = std::min(a1,b1);} } return Left < Right; } //------------------------------------------------------------------------------ inline void UpdateOutPtIdxs(OutRec& outrec) { OutPt* op = outrec.Pts; do { op->Idx = outrec.Idx; op = op->Prev; } while(op != outrec.Pts); } //------------------------------------------------------------------------------ void Clipper::InsertEdgeIntoAEL(TEdge *edge, TEdge* startEdge) { if(!m_ActiveEdges) { edge->PrevInAEL = 0; edge->NextInAEL = 0; m_ActiveEdges = edge; } else if(!startEdge && E2InsertsBeforeE1(*m_ActiveEdges, *edge)) { edge->PrevInAEL = 0; edge->NextInAEL = m_ActiveEdges; m_ActiveEdges->PrevInAEL = edge; m_ActiveEdges = edge; } else { if(!startEdge) startEdge = m_ActiveEdges; while(startEdge->NextInAEL && !E2InsertsBeforeE1(*startEdge->NextInAEL , *edge)) startEdge = startEdge->NextInAEL; edge->NextInAEL = startEdge->NextInAEL; if(startEdge->NextInAEL) startEdge->NextInAEL->PrevInAEL = edge; edge->PrevInAEL = startEdge; startEdge->NextInAEL = edge; } } //---------------------------------------------------------------------- OutPt* DupOutPt(OutPt* outPt, bool InsertAfter) { OutPt* result = new OutPt; result->Pt = outPt->Pt; result->Idx = outPt->Idx; if (InsertAfter) { result->Next = outPt->Next; result->Prev = outPt; outPt->Next->Prev = result; outPt->Next = result; } else { result->Prev = outPt->Prev; result->Next = outPt; outPt->Prev->Next = result; outPt->Prev = result; } return result; } //------------------------------------------------------------------------------ bool JoinHorz(OutPt* op1, OutPt* op1b, OutPt* op2, OutPt* op2b, const IntPoint Pt, bool DiscardLeft) { Direction Dir1 = (op1->Pt.X > op1b->Pt.X ? dRightToLeft : dLeftToRight); Direction Dir2 = (op2->Pt.X > op2b->Pt.X ? dRightToLeft : dLeftToRight); if (Dir1 == Dir2) return false; //When DiscardLeft, we want Op1b to be on the Left of Op1, otherwise we //want Op1b to be on the Right. (And likewise with Op2 and Op2b.) //So, to facilitate this while inserting Op1b and Op2b ... //when DiscardLeft, make sure we're AT or RIGHT of Pt before adding Op1b, //otherwise make sure we're AT or LEFT of Pt. (Likewise with Op2b.) if (Dir1 == dLeftToRight) { while (op1->Next->Pt.X <= Pt.X && op1->Next->Pt.X >= op1->Pt.X && op1->Next->Pt.Y == Pt.Y) op1 = op1->Next; if (DiscardLeft && (op1->Pt.X != Pt.X)) op1 = op1->Next; op1b = DupOutPt(op1, !DiscardLeft); if (op1b->Pt != Pt) { op1 = op1b; op1->Pt = Pt; op1b = DupOutPt(op1, !DiscardLeft); } } else { while (op1->Next->Pt.X >= Pt.X && op1->Next->Pt.X <= op1->Pt.X && op1->Next->Pt.Y == Pt.Y) op1 = op1->Next; if (!DiscardLeft && (op1->Pt.X != Pt.X)) op1 = op1->Next; op1b = DupOutPt(op1, DiscardLeft); if (op1b->Pt != Pt) { op1 = op1b; op1->Pt = Pt; op1b = DupOutPt(op1, DiscardLeft); } } if (Dir2 == dLeftToRight) { while (op2->Next->Pt.X <= Pt.X && op2->Next->Pt.X >= op2->Pt.X && op2->Next->Pt.Y == Pt.Y) op2 = op2->Next; if (DiscardLeft && (op2->Pt.X != Pt.X)) op2 = op2->Next; op2b = DupOutPt(op2, !DiscardLeft); if (op2b->Pt != Pt) { op2 = op2b; op2->Pt = Pt; op2b = DupOutPt(op2, !DiscardLeft); }; } else { while (op2->Next->Pt.X >= Pt.X && op2->Next->Pt.X <= op2->Pt.X && op2->Next->Pt.Y == Pt.Y) op2 = op2->Next; if (!DiscardLeft && (op2->Pt.X != Pt.X)) op2 = op2->Next; op2b = DupOutPt(op2, DiscardLeft); if (op2b->Pt != Pt) { op2 = op2b; op2->Pt = Pt; op2b = DupOutPt(op2, DiscardLeft); }; }; if ((Dir1 == dLeftToRight) == DiscardLeft) { op1->Prev = op2; op2->Next = op1; op1b->Next = op2b; op2b->Prev = op1b; } else { op1->Next = op2; op2->Prev = op1; op1b->Prev = op2b; op2b->Next = op1b; } return true; } //------------------------------------------------------------------------------ bool Clipper::JoinPoints(Join *j, OutRec* outRec1, OutRec* outRec2) { OutPt *op1 = j->OutPt1, *op1b; OutPt *op2 = j->OutPt2, *op2b; //There are 3 kinds of joins for output polygons ... //1. Horizontal joins where Join.OutPt1 & Join.OutPt2 are vertices anywhere //along (horizontal) collinear edges (& Join.OffPt is on the same horizontal). //2. Non-horizontal joins where Join.OutPt1 & Join.OutPt2 are at the same //location at the Bottom of the overlapping segment (& Join.OffPt is above). //3. StrictSimple joins where edges touch but are not collinear and where //Join.OutPt1, Join.OutPt2 & Join.OffPt all share the same point. bool isHorizontal = (j->OutPt1->Pt.Y == j->OffPt.Y); if (isHorizontal && (j->OffPt == j->OutPt1->Pt) && (j->OffPt == j->OutPt2->Pt)) { //Strictly Simple join ... if (outRec1 != outRec2) return false; op1b = j->OutPt1->Next; while (op1b != op1 && (op1b->Pt == j->OffPt)) op1b = op1b->Next; bool reverse1 = (op1b->Pt.Y > j->OffPt.Y); op2b = j->OutPt2->Next; while (op2b != op2 && (op2b->Pt == j->OffPt)) op2b = op2b->Next; bool reverse2 = (op2b->Pt.Y > j->OffPt.Y); if (reverse1 == reverse2) return false; if (reverse1) { op1b = DupOutPt(op1, false); op2b = DupOutPt(op2, true); op1->Prev = op2; op2->Next = op1; op1b->Next = op2b; op2b->Prev = op1b; j->OutPt1 = op1; j->OutPt2 = op1b; return true; } else { op1b = DupOutPt(op1, true); op2b = DupOutPt(op2, false); op1->Next = op2; op2->Prev = op1; op1b->Prev = op2b; op2b->Next = op1b; j->OutPt1 = op1; j->OutPt2 = op1b; return true; } } else if (isHorizontal) { //treat horizontal joins differently to non-horizontal joins since with //them we're not yet sure where the overlapping is. OutPt1.Pt & OutPt2.Pt //may be anywhere along the horizontal edge. op1b = op1; while (op1->Prev->Pt.Y == op1->Pt.Y && op1->Prev != op1b && op1->Prev != op2) op1 = op1->Prev; while (op1b->Next->Pt.Y == op1b->Pt.Y && op1b->Next != op1 && op1b->Next != op2) op1b = op1b->Next; if (op1b->Next == op1 || op1b->Next == op2) return false; //a flat 'polygon' op2b = op2; while (op2->Prev->Pt.Y == op2->Pt.Y && op2->Prev != op2b && op2->Prev != op1b) op2 = op2->Prev; while (op2b->Next->Pt.Y == op2b->Pt.Y && op2b->Next != op2 && op2b->Next != op1) op2b = op2b->Next; if (op2b->Next == op2 || op2b->Next == op1) return false; //a flat 'polygon' cInt Left, Right; //Op1 --> Op1b & Op2 --> Op2b are the extremites of the horizontal edges if (!GetOverlap(op1->Pt.X, op1b->Pt.X, op2->Pt.X, op2b->Pt.X, Left, Right)) return false; //DiscardLeftSide: when overlapping edges are joined, a spike will created //which needs to be cleaned up. However, we don't want Op1 or Op2 caught up //on the discard Side as either may still be needed for other joins ... IntPoint Pt; bool DiscardLeftSide; if (op1->Pt.X >= Left && op1->Pt.X <= Right) { Pt = op1->Pt; DiscardLeftSide = (op1->Pt.X > op1b->Pt.X); } else if (op2->Pt.X >= Left&& op2->Pt.X <= Right) { Pt = op2->Pt; DiscardLeftSide = (op2->Pt.X > op2b->Pt.X); } else if (op1b->Pt.X >= Left && op1b->Pt.X <= Right) { Pt = op1b->Pt; DiscardLeftSide = op1b->Pt.X > op1->Pt.X; } else { Pt = op2b->Pt; DiscardLeftSide = (op2b->Pt.X > op2->Pt.X); } j->OutPt1 = op1; j->OutPt2 = op2; return JoinHorz(op1, op1b, op2, op2b, Pt, DiscardLeftSide); } else { //nb: For non-horizontal joins ... // 1. Jr.OutPt1.Pt.Y == Jr.OutPt2.Pt.Y // 2. Jr.OutPt1.Pt > Jr.OffPt.Y //make sure the polygons are correctly oriented ... op1b = op1->Next; while ((op1b->Pt == op1->Pt) && (op1b != op1)) op1b = op1b->Next; bool Reverse1 = ((op1b->Pt.Y > op1->Pt.Y) || !SlopesEqual(op1->Pt, op1b->Pt, j->OffPt, m_UseFullRange)); if (Reverse1) { op1b = op1->Prev; while ((op1b->Pt == op1->Pt) && (op1b != op1)) op1b = op1b->Prev; if ((op1b->Pt.Y > op1->Pt.Y) || !SlopesEqual(op1->Pt, op1b->Pt, j->OffPt, m_UseFullRange)) return false; }; op2b = op2->Next; while ((op2b->Pt == op2->Pt) && (op2b != op2))op2b = op2b->Next; bool Reverse2 = ((op2b->Pt.Y > op2->Pt.Y) || !SlopesEqual(op2->Pt, op2b->Pt, j->OffPt, m_UseFullRange)); if (Reverse2) { op2b = op2->Prev; while ((op2b->Pt == op2->Pt) && (op2b != op2)) op2b = op2b->Prev; if ((op2b->Pt.Y > op2->Pt.Y) || !SlopesEqual(op2->Pt, op2b->Pt, j->OffPt, m_UseFullRange)) return false; } if ((op1b == op1) || (op2b == op2) || (op1b == op2b) || ((outRec1 == outRec2) && (Reverse1 == Reverse2))) return false; if (Reverse1) { op1b = DupOutPt(op1, false); op2b = DupOutPt(op2, true); op1->Prev = op2; op2->Next = op1; op1b->Next = op2b; op2b->Prev = op1b; j->OutPt1 = op1; j->OutPt2 = op1b; return true; } else { op1b = DupOutPt(op1, true); op2b = DupOutPt(op2, false); op1->Next = op2; op2->Prev = op1; op1b->Prev = op2b; op2b->Next = op1b; j->OutPt1 = op1; j->OutPt2 = op1b; return true; } } } //---------------------------------------------------------------------- static OutRec* ParseFirstLeft(OutRec* FirstLeft) { while (FirstLeft && !FirstLeft->Pts) FirstLeft = FirstLeft->FirstLeft; return FirstLeft; } //------------------------------------------------------------------------------ void Clipper::FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec) { //tests if NewOutRec contains the polygon before reassigning FirstLeft for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i) { OutRec* outRec = m_PolyOuts[i]; OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft); if (outRec->Pts && firstLeft == OldOutRec) { if (Poly2ContainsPoly1(outRec->Pts, NewOutRec->Pts)) outRec->FirstLeft = NewOutRec; } } } //---------------------------------------------------------------------- void Clipper::FixupFirstLefts2(OutRec* InnerOutRec, OutRec* OuterOutRec) { //A polygon has split into two such that one is now the inner of the other. //It's possible that these polygons now wrap around other polygons, so check //every polygon that's also contained by OuterOutRec's FirstLeft container //(including 0) to see if they've become inner to the new inner polygon ... OutRec* orfl = OuterOutRec->FirstLeft; for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i) { OutRec* outRec = m_PolyOuts[i]; if (!outRec->Pts || outRec == OuterOutRec || outRec == InnerOutRec) continue; OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft); if (firstLeft != orfl && firstLeft != InnerOutRec && firstLeft != OuterOutRec) continue; if (Poly2ContainsPoly1(outRec->Pts, InnerOutRec->Pts)) outRec->FirstLeft = InnerOutRec; else if (Poly2ContainsPoly1(outRec->Pts, OuterOutRec->Pts)) outRec->FirstLeft = OuterOutRec; else if (outRec->FirstLeft == InnerOutRec || outRec->FirstLeft == OuterOutRec) outRec->FirstLeft = orfl; } } //---------------------------------------------------------------------- void Clipper::FixupFirstLefts3(OutRec* OldOutRec, OutRec* NewOutRec) { //reassigns FirstLeft WITHOUT testing if NewOutRec contains the polygon for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i) { OutRec* outRec = m_PolyOuts[i]; OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft); if (outRec->Pts && outRec->FirstLeft == OldOutRec) outRec->FirstLeft = NewOutRec; } } //---------------------------------------------------------------------- void Clipper::JoinCommonEdges() { for (JoinList::size_type i = 0; i < m_Joins.size(); i++) { Join* join = m_Joins[i]; OutRec *outRec1 = GetOutRec(join->OutPt1->Idx); OutRec *outRec2 = GetOutRec(join->OutPt2->Idx); if (!outRec1->Pts || !outRec2->Pts) continue; if (outRec1->IsOpen || outRec2->IsOpen) continue; //get the polygon fragment with the correct hole state (FirstLeft) //before calling JoinPoints() ... OutRec *holeStateRec; if (outRec1 == outRec2) holeStateRec = outRec1; else if (OutRec1RightOfOutRec2(outRec1, outRec2)) holeStateRec = outRec2; else if (OutRec1RightOfOutRec2(outRec2, outRec1)) holeStateRec = outRec1; else holeStateRec = GetLowermostRec(outRec1, outRec2); if (!JoinPoints(join, outRec1, outRec2)) continue; if (outRec1 == outRec2) { //instead of joining two polygons, we've just created a new one by //splitting one polygon into two. outRec1->Pts = join->OutPt1; outRec1->BottomPt = 0; outRec2 = CreateOutRec(); outRec2->Pts = join->OutPt2; //update all OutRec2.Pts Idx's ... UpdateOutPtIdxs(*outRec2); if (Poly2ContainsPoly1(outRec2->Pts, outRec1->Pts)) { //outRec1 contains outRec2 ... outRec2->IsHole = !outRec1->IsHole; outRec2->FirstLeft = outRec1; if (m_UsingPolyTree) FixupFirstLefts2(outRec2, outRec1); if ((outRec2->IsHole ^ m_ReverseOutput) == (Area(*outRec2) > 0)) ReversePolyPtLinks(outRec2->Pts); } else if (Poly2ContainsPoly1(outRec1->Pts, outRec2->Pts)) { //outRec2 contains outRec1 ... outRec2->IsHole = outRec1->IsHole; outRec1->IsHole = !outRec2->IsHole; outRec2->FirstLeft = outRec1->FirstLeft; outRec1->FirstLeft = outRec2; if (m_UsingPolyTree) FixupFirstLefts2(outRec1, outRec2); if ((outRec1->IsHole ^ m_ReverseOutput) == (Area(*outRec1) > 0)) ReversePolyPtLinks(outRec1->Pts); } else { //the 2 polygons are completely separate ... outRec2->IsHole = outRec1->IsHole; outRec2->FirstLeft = outRec1->FirstLeft; //fixup FirstLeft pointers that may need reassigning to OutRec2 if (m_UsingPolyTree) FixupFirstLefts1(outRec1, outRec2); } } else { //joined 2 polygons together ... outRec2->Pts = 0; outRec2->BottomPt = 0; outRec2->Idx = outRec1->Idx; outRec1->IsHole = holeStateRec->IsHole; if (holeStateRec == outRec2) outRec1->FirstLeft = outRec2->FirstLeft; outRec2->FirstLeft = outRec1; if (m_UsingPolyTree) FixupFirstLefts3(outRec2, outRec1); } } } //------------------------------------------------------------------------------ // ClipperOffset support functions ... //------------------------------------------------------------------------------ DoublePoint GetUnitNormal(const IntPoint &pt1, const IntPoint &pt2) { if(pt2.X == pt1.X && pt2.Y == pt1.Y) return DoublePoint(0, 0); double Dx = (double)(pt2.X - pt1.X); double dy = (double)(pt2.Y - pt1.Y); double f = 1 *1.0/ std::sqrt( Dx*Dx + dy*dy ); Dx *= f; dy *= f; return DoublePoint(dy, -Dx); } //------------------------------------------------------------------------------ // ClipperOffset class //------------------------------------------------------------------------------ ClipperOffset::ClipperOffset(double miterLimit, double arcTolerance) { this->MiterLimit = miterLimit; this->ArcTolerance = arcTolerance; m_lowest.X = -1; } //------------------------------------------------------------------------------ ClipperOffset::~ClipperOffset() { Clear(); } //------------------------------------------------------------------------------ void ClipperOffset::Clear() { for (int i = 0; i < m_polyNodes.ChildCount(); ++i) delete m_polyNodes.Childs[i]; m_polyNodes.Childs.clear(); m_lowest.X = -1; } //------------------------------------------------------------------------------ void ClipperOffset::AddPath(const Path& path, JoinType joinType, EndType endType) { int highI = (int)path.size() - 1; if (highI < 0) return; PolyNode* newNode = new PolyNode(); newNode->m_jointype = joinType; newNode->m_endtype = endType; //strip duplicate points from path and also get index to the lowest point ... if (endType == etClosedLine || endType == etClosedPolygon) while (highI > 0 && path[0] == path[highI]) highI--; newNode->Contour.reserve(highI + 1); newNode->Contour.push_back(path[0]); int j = 0, k = 0; for (int i = 1; i <= highI; i++) if (newNode->Contour[j] != path[i]) { j++; newNode->Contour.push_back(path[i]); if (path[i].Y > newNode->Contour[k].Y || (path[i].Y == newNode->Contour[k].Y && path[i].X < newNode->Contour[k].X)) k = j; } if (endType == etClosedPolygon && j < 2) { delete newNode; return; } m_polyNodes.AddChild(*newNode); //if this path's lowest pt is lower than all the others then update m_lowest if (endType != etClosedPolygon) return; if (m_lowest.X < 0) m_lowest = IntPoint(m_polyNodes.ChildCount() - 1, k); else { IntPoint ip = m_polyNodes.Childs[(int)m_lowest.X]->Contour[(int)m_lowest.Y]; if (newNode->Contour[k].Y > ip.Y || (newNode->Contour[k].Y == ip.Y && newNode->Contour[k].X < ip.X)) m_lowest = IntPoint(m_polyNodes.ChildCount() - 1, k); } } //------------------------------------------------------------------------------ void ClipperOffset::AddPaths(const Paths& paths, JoinType joinType, EndType endType) { for (Paths::size_type i = 0; i < paths.size(); ++i) AddPath(paths[i], joinType, endType); } //------------------------------------------------------------------------------ void ClipperOffset::FixOrientations() { //fixup orientations of all closed paths if the orientation of the //closed path with the lowermost vertex is wrong ... if (m_lowest.X >= 0 && !Orientation(m_polyNodes.Childs[(int)m_lowest.X]->Contour)) { for (int i = 0; i < m_polyNodes.ChildCount(); ++i) { PolyNode& node = *m_polyNodes.Childs[i]; if (node.m_endtype == etClosedPolygon || (node.m_endtype == etClosedLine && Orientation(node.Contour))) ReversePath(node.Contour); } } else { for (int i = 0; i < m_polyNodes.ChildCount(); ++i) { PolyNode& node = *m_polyNodes.Childs[i]; if (node.m_endtype == etClosedLine && !Orientation(node.Contour)) ReversePath(node.Contour); } } } //------------------------------------------------------------------------------ void ClipperOffset::Execute(Paths& solution, double delta) { solution.clear(); FixOrientations(); DoOffset(delta); //now clean up 'corners' ... Clipper clpr; clpr.AddPaths(m_destPolys, ptSubject, true); if (delta > 0) { clpr.Execute(ctUnion, solution, pftPositive, pftPositive); } else { IntRect r = clpr.GetBounds(); Path outer(4); outer[0] = IntPoint(r.left - 10, r.bottom + 10); outer[1] = IntPoint(r.right + 10, r.bottom + 10); outer[2] = IntPoint(r.right + 10, r.top - 10); outer[3] = IntPoint(r.left - 10, r.top - 10); clpr.AddPath(outer, ptSubject, true); clpr.ReverseSolution(true); clpr.Execute(ctUnion, solution, pftNegative, pftNegative); if (solution.size() > 0) solution.erase(solution.begin()); } } //------------------------------------------------------------------------------ void ClipperOffset::Execute(PolyTree& solution, double delta) { solution.Clear(); FixOrientations(); DoOffset(delta); //now clean up 'corners' ... Clipper clpr; clpr.AddPaths(m_destPolys, ptSubject, true); if (delta > 0) { clpr.Execute(ctUnion, solution, pftPositive, pftPositive); } else { IntRect r = clpr.GetBounds(); Path outer(4); outer[0] = IntPoint(r.left - 10, r.bottom + 10); outer[1] = IntPoint(r.right + 10, r.bottom + 10); outer[2] = IntPoint(r.right + 10, r.top - 10); outer[3] = IntPoint(r.left - 10, r.top - 10); clpr.AddPath(outer, ptSubject, true); clpr.ReverseSolution(true); clpr.Execute(ctUnion, solution, pftNegative, pftNegative); //remove the outer PolyNode rectangle ... if (solution.ChildCount() == 1 && solution.Childs[0]->ChildCount() > 0) { PolyNode* outerNode = solution.Childs[0]; solution.Childs.reserve(outerNode->ChildCount()); solution.Childs[0] = outerNode->Childs[0]; solution.Childs[0]->Parent = outerNode->Parent; for (int i = 1; i < outerNode->ChildCount(); ++i) solution.AddChild(*outerNode->Childs[i]); } else solution.Clear(); } } //------------------------------------------------------------------------------ void ClipperOffset::DoOffset(double delta) { m_destPolys.clear(); m_delta = delta; //if Zero offset, just copy any CLOSED polygons to m_p and return ... if (NEAR_ZERO(delta)) { m_destPolys.reserve(m_polyNodes.ChildCount()); for (int i = 0; i < m_polyNodes.ChildCount(); i++) { PolyNode& node = *m_polyNodes.Childs[i]; if (node.m_endtype == etClosedPolygon) m_destPolys.push_back(node.Contour); } return; } //see offset_triginometry3.svg in the documentation folder ... if (MiterLimit > 2) m_miterLim = 2/(MiterLimit * MiterLimit); else m_miterLim = 0.5; double y; if (ArcTolerance <= 0.0) y = def_arc_tolerance; else if (ArcTolerance > std::fabs(delta) * def_arc_tolerance) y = std::fabs(delta) * def_arc_tolerance; else y = ArcTolerance; //see offset_triginometry2.svg in the documentation folder ... double steps = pi / std::acos(1 - y / std::fabs(delta)); if (steps > std::fabs(delta) * pi) steps = std::fabs(delta) * pi; //ie excessive precision check m_sin = std::sin(two_pi / steps); m_cos = std::cos(two_pi / steps); m_StepsPerRad = steps / two_pi; if (delta < 0.0) m_sin = -m_sin; m_destPolys.reserve(m_polyNodes.ChildCount() * 2); for (int i = 0; i < m_polyNodes.ChildCount(); i++) { PolyNode& node = *m_polyNodes.Childs[i]; m_srcPoly = node.Contour; int len = (int)m_srcPoly.size(); if (len == 0 || (delta <= 0 && (len < 3 || node.m_endtype != etClosedPolygon))) continue; m_destPoly.clear(); if (len == 1) { if (node.m_jointype == jtRound) { double X = 1.0, Y = 0.0; for (cInt j = 1; j <= steps; j++) { m_destPoly.push_back(IntPoint( Round(m_srcPoly[0].X + X * delta), Round(m_srcPoly[0].Y + Y * delta))); double X2 = X; X = X * m_cos - m_sin * Y; Y = X2 * m_sin + Y * m_cos; } } else { double X = -1.0, Y = -1.0; for (int j = 0; j < 4; ++j) { m_destPoly.push_back(IntPoint( Round(m_srcPoly[0].X + X * delta), Round(m_srcPoly[0].Y + Y * delta))); if (X < 0) X = 1; else if (Y < 0) Y = 1; else X = -1; } } m_destPolys.push_back(m_destPoly); continue; } //build m_normals ... m_normals.clear(); m_normals.reserve(len); for (int j = 0; j < len - 1; ++j) m_normals.push_back(GetUnitNormal(m_srcPoly[j], m_srcPoly[j + 1])); if (node.m_endtype == etClosedLine || node.m_endtype == etClosedPolygon) m_normals.push_back(GetUnitNormal(m_srcPoly[len - 1], m_srcPoly[0])); else m_normals.push_back(DoublePoint(m_normals[len - 2])); if (node.m_endtype == etClosedPolygon) { int k = len - 1; for (int j = 0; j < len; ++j) OffsetPoint(j, k, node.m_jointype); m_destPolys.push_back(m_destPoly); } else if (node.m_endtype == etClosedLine) { int k = len - 1; for (int j = 0; j < len; ++j) OffsetPoint(j, k, node.m_jointype); m_destPolys.push_back(m_destPoly); m_destPoly.clear(); //re-build m_normals ... DoublePoint n = m_normals[len -1]; for (int j = len - 1; j > 0; j--) m_normals[j] = DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y); m_normals[0] = DoublePoint(-n.X, -n.Y); k = 0; for (int j = len - 1; j >= 0; j--) OffsetPoint(j, k, node.m_jointype); m_destPolys.push_back(m_destPoly); } else { int k = 0; for (int j = 1; j < len - 1; ++j) OffsetPoint(j, k, node.m_jointype); IntPoint pt1; if (node.m_endtype == etOpenButt) { int j = len - 1; pt1 = IntPoint((cInt)Round(m_srcPoly[j].X + m_normals[j].X * delta), (cInt)Round(m_srcPoly[j].Y + m_normals[j].Y * delta)); m_destPoly.push_back(pt1); pt1 = IntPoint((cInt)Round(m_srcPoly[j].X - m_normals[j].X * delta), (cInt)Round(m_srcPoly[j].Y - m_normals[j].Y * delta)); m_destPoly.push_back(pt1); } else { int j = len - 1; k = len - 2; m_sinA = 0; m_normals[j] = DoublePoint(-m_normals[j].X, -m_normals[j].Y); if (node.m_endtype == etOpenSquare) DoSquare(j, k); else DoRound(j, k); } //re-build m_normals ... for (int j = len - 1; j > 0; j--) m_normals[j] = DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y); m_normals[0] = DoublePoint(-m_normals[1].X, -m_normals[1].Y); k = len - 1; for (int j = k - 1; j > 0; --j) OffsetPoint(j, k, node.m_jointype); if (node.m_endtype == etOpenButt) { pt1 = IntPoint((cInt)Round(m_srcPoly[0].X - m_normals[0].X * delta), (cInt)Round(m_srcPoly[0].Y - m_normals[0].Y * delta)); m_destPoly.push_back(pt1); pt1 = IntPoint((cInt)Round(m_srcPoly[0].X + m_normals[0].X * delta), (cInt)Round(m_srcPoly[0].Y + m_normals[0].Y * delta)); m_destPoly.push_back(pt1); } else { k = 1; m_sinA = 0; if (node.m_endtype == etOpenSquare) DoSquare(0, 1); else DoRound(0, 1); } m_destPolys.push_back(m_destPoly); } } } //------------------------------------------------------------------------------ void ClipperOffset::OffsetPoint(int j, int& k, JoinType jointype) { //cross product ... m_sinA = (m_normals[k].X * m_normals[j].Y - m_normals[j].X * m_normals[k].Y); if (std::fabs(m_sinA * m_delta) < 1.0) { //dot product ... double cosA = (m_normals[k].X * m_normals[j].X + m_normals[j].Y * m_normals[k].Y ); if (cosA > 0) // angle => 0 degrees { m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta), Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta))); return; } //else angle => 180 degrees } else if (m_sinA > 1.0) m_sinA = 1.0; else if (m_sinA < -1.0) m_sinA = -1.0; if (m_sinA * m_delta < 0) { m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta), Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta))); m_destPoly.push_back(m_srcPoly[j]); m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[j].X * m_delta), Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta))); } else switch (jointype) { case jtMiter: { double r = 1 + (m_normals[j].X * m_normals[k].X + m_normals[j].Y * m_normals[k].Y); if (r >= m_miterLim) DoMiter(j, k, r); else DoSquare(j, k); break; } case jtSquare: DoSquare(j, k); break; case jtRound: DoRound(j, k); break; } k = j; } //------------------------------------------------------------------------------ void ClipperOffset::DoSquare(int j, int k) { double dx = std::tan(std::atan2(m_sinA, m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y) / 4); m_destPoly.push_back(IntPoint( Round(m_srcPoly[j].X + m_delta * (m_normals[k].X - m_normals[k].Y * dx)), Round(m_srcPoly[j].Y + m_delta * (m_normals[k].Y + m_normals[k].X * dx)))); m_destPoly.push_back(IntPoint( Round(m_srcPoly[j].X + m_delta * (m_normals[j].X + m_normals[j].Y * dx)), Round(m_srcPoly[j].Y + m_delta * (m_normals[j].Y - m_normals[j].X * dx)))); } //------------------------------------------------------------------------------ void ClipperOffset::DoMiter(int j, int k, double r) { double q = m_delta / r; m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + (m_normals[k].X + m_normals[j].X) * q), Round(m_srcPoly[j].Y + (m_normals[k].Y + m_normals[j].Y) * q))); } //------------------------------------------------------------------------------ void ClipperOffset::DoRound(int j, int k) { double a = std::atan2(m_sinA, m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y); int steps = std::max((int)Round(m_StepsPerRad * std::fabs(a)), 1); double X = m_normals[k].X, Y = m_normals[k].Y, X2; for (int i = 0; i < steps; ++i) { m_destPoly.push_back(IntPoint( Round(m_srcPoly[j].X + X * m_delta), Round(m_srcPoly[j].Y + Y * m_delta))); X2 = X; X = X * m_cos - m_sin * Y; Y = X2 * m_sin + Y * m_cos; } m_destPoly.push_back(IntPoint( Round(m_srcPoly[j].X + m_normals[j].X * m_delta), Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta))); } //------------------------------------------------------------------------------ // Miscellaneous public functions //------------------------------------------------------------------------------ void Clipper::DoSimplePolygons() { PolyOutList::size_type i = 0; while (i < m_PolyOuts.size()) { OutRec* outrec = m_PolyOuts[i++]; OutPt* op = outrec->Pts; if (!op || outrec->IsOpen) continue; do //for each Pt in Polygon until duplicate found do ... { OutPt* op2 = op->Next; while (op2 != outrec->Pts) { if ((op->Pt == op2->Pt) && op2->Next != op && op2->Prev != op) { //split the polygon into two ... OutPt* op3 = op->Prev; OutPt* op4 = op2->Prev; op->Prev = op4; op4->Next = op; op2->Prev = op3; op3->Next = op2; outrec->Pts = op; OutRec* outrec2 = CreateOutRec(); outrec2->Pts = op2; UpdateOutPtIdxs(*outrec2); if (Poly2ContainsPoly1(outrec2->Pts, outrec->Pts)) { //OutRec2 is contained by OutRec1 ... outrec2->IsHole = !outrec->IsHole; outrec2->FirstLeft = outrec; if (m_UsingPolyTree) FixupFirstLefts2(outrec2, outrec); } else if (Poly2ContainsPoly1(outrec->Pts, outrec2->Pts)) { //OutRec1 is contained by OutRec2 ... outrec2->IsHole = outrec->IsHole; outrec->IsHole = !outrec2->IsHole; outrec2->FirstLeft = outrec->FirstLeft; outrec->FirstLeft = outrec2; if (m_UsingPolyTree) FixupFirstLefts2(outrec, outrec2); } else { //the 2 polygons are separate ... outrec2->IsHole = outrec->IsHole; outrec2->FirstLeft = outrec->FirstLeft; if (m_UsingPolyTree) FixupFirstLefts1(outrec, outrec2); } op2 = op; //ie get ready for the Next iteration } op2 = op2->Next; } op = op->Next; } while (op != outrec->Pts); } } //------------------------------------------------------------------------------ void ReversePath(Path& p) { std::reverse(p.begin(), p.end()); } //------------------------------------------------------------------------------ void ReversePaths(Paths& p) { for (Paths::size_type i = 0; i < p.size(); ++i) ReversePath(p[i]); } //------------------------------------------------------------------------------ void SimplifyPolygon(const Path &in_poly, Paths &out_polys, PolyFillType fillType) { Clipper c; c.StrictlySimple(true); c.AddPath(in_poly, ptSubject, true); c.Execute(ctUnion, out_polys, fillType, fillType); } //------------------------------------------------------------------------------ void SimplifyPolygons(const Paths &in_polys, Paths &out_polys, PolyFillType fillType) { Clipper c; c.StrictlySimple(true); c.AddPaths(in_polys, ptSubject, true); c.Execute(ctUnion, out_polys, fillType, fillType); } //------------------------------------------------------------------------------ void SimplifyPolygons(Paths &polys, PolyFillType fillType) { SimplifyPolygons(polys, polys, fillType); } //------------------------------------------------------------------------------ inline double DistanceSqrd(const IntPoint& pt1, const IntPoint& pt2) { double Dx = ((double)pt1.X - pt2.X); double dy = ((double)pt1.Y - pt2.Y); return (Dx*Dx + dy*dy); } //------------------------------------------------------------------------------ double DistanceFromLineSqrd( const IntPoint& pt, const IntPoint& ln1, const IntPoint& ln2) { //The equation of a line in general form (Ax + By + C = 0) //given 2 points (x¹,y¹) & (x²,y²) is ... //(y¹ - y²)x + (x² - x¹)y + (y² - y¹)x¹ - (x² - x¹)y¹ = 0 //A = (y¹ - y²); B = (x² - x¹); C = (y² - y¹)x¹ - (x² - x¹)y¹ //perpendicular distance of point (x³,y³) = (Ax³ + By³ + C)/Sqrt(A² + B²) //see http://en.wikipedia.org/wiki/Perpendicular_distance double A = double(ln1.Y - ln2.Y); double B = double(ln2.X - ln1.X); double C = A * ln1.X + B * ln1.Y; C = A * pt.X + B * pt.Y - C; return (C * C) / (A * A + B * B); } //--------------------------------------------------------------------------- bool SlopesNearCollinear(const IntPoint& pt1, const IntPoint& pt2, const IntPoint& pt3, double distSqrd) { //this function is more accurate when the point that's geometrically //between the other 2 points is the one that's tested for distance. //ie makes it more likely to pick up 'spikes' ... if (Abs(pt1.X - pt2.X) > Abs(pt1.Y - pt2.Y)) { if ((pt1.X > pt2.X) == (pt1.X < pt3.X)) return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd; else if ((pt2.X > pt1.X) == (pt2.X < pt3.X)) return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd; else return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd; } else { if ((pt1.Y > pt2.Y) == (pt1.Y < pt3.Y)) return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd; else if ((pt2.Y > pt1.Y) == (pt2.Y < pt3.Y)) return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd; else return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd; } } //------------------------------------------------------------------------------ bool PointsAreClose(IntPoint pt1, IntPoint pt2, double distSqrd) { double Dx = (double)pt1.X - pt2.X; double dy = (double)pt1.Y - pt2.Y; return ((Dx * Dx) + (dy * dy) <= distSqrd); } //------------------------------------------------------------------------------ OutPt* ExcludeOp(OutPt* op) { OutPt* result = op->Prev; result->Next = op->Next; op->Next->Prev = result; result->Idx = 0; return result; } //------------------------------------------------------------------------------ void CleanPolygon(const Path& in_poly, Path& out_poly, double distance) { //distance = proximity in units/pixels below which vertices //will be stripped. Default ~= sqrt(2). size_t size = in_poly.size(); if (size == 0) { out_poly.clear(); return; } OutPt* outPts = new OutPt[size]; for (size_t i = 0; i < size; ++i) { outPts[i].Pt = in_poly[i]; outPts[i].Next = &outPts[(i + 1) % size]; outPts[i].Next->Prev = &outPts[i]; outPts[i].Idx = 0; } double distSqrd = distance * distance; OutPt* op = &outPts[0]; while (op->Idx == 0 && op->Next != op->Prev) { if (PointsAreClose(op->Pt, op->Prev->Pt, distSqrd)) { op = ExcludeOp(op); size--; } else if (PointsAreClose(op->Prev->Pt, op->Next->Pt, distSqrd)) { ExcludeOp(op->Next); op = ExcludeOp(op); size -= 2; } else if (SlopesNearCollinear(op->Prev->Pt, op->Pt, op->Next->Pt, distSqrd)) { op = ExcludeOp(op); size--; } else { op->Idx = 1; op = op->Next; } } if (size < 3) size = 0; out_poly.resize(size); for (size_t i = 0; i < size; ++i) { out_poly[i] = op->Pt; op = op->Next; } delete [] outPts; } //------------------------------------------------------------------------------ void CleanPolygon(Path& poly, double distance) { CleanPolygon(poly, poly, distance); } //------------------------------------------------------------------------------ void CleanPolygons(const Paths& in_polys, Paths& out_polys, double distance) { out_polys.resize(in_polys.size()); for (Paths::size_type i = 0; i < in_polys.size(); ++i) CleanPolygon(in_polys[i], out_polys[i], distance); } //------------------------------------------------------------------------------ void CleanPolygons(Paths& polys, double distance) { CleanPolygons(polys, polys, distance); } //------------------------------------------------------------------------------ void Minkowski(const Path& poly, const Path& path, Paths& solution, bool isSum, bool isClosed) { int delta = (isClosed ? 1 : 0); size_t polyCnt = poly.size(); size_t pathCnt = path.size(); Paths pp; pp.reserve(pathCnt); if (isSum) for (size_t i = 0; i < pathCnt; ++i) { Path p; p.reserve(polyCnt); for (size_t j = 0; j < poly.size(); ++j) p.push_back(IntPoint(path[i].X + poly[j].X, path[i].Y + poly[j].Y)); pp.push_back(p); } else for (size_t i = 0; i < pathCnt; ++i) { Path p; p.reserve(polyCnt); for (size_t j = 0; j < poly.size(); ++j) p.push_back(IntPoint(path[i].X - poly[j].X, path[i].Y - poly[j].Y)); pp.push_back(p); } solution.clear(); solution.reserve((pathCnt + delta) * (polyCnt + 1)); for (size_t i = 0; i < pathCnt - 1 + delta; ++i) for (size_t j = 0; j < polyCnt; ++j) { Path quad; quad.reserve(4); quad.push_back(pp[i % pathCnt][j % polyCnt]); quad.push_back(pp[(i + 1) % pathCnt][j % polyCnt]); quad.push_back(pp[(i + 1) % pathCnt][(j + 1) % polyCnt]); quad.push_back(pp[i % pathCnt][(j + 1) % polyCnt]); if (!Orientation(quad)) ReversePath(quad); solution.push_back(quad); } } //------------------------------------------------------------------------------ void MinkowskiSum(const Path& pattern, const Path& path, Paths& solution, bool pathIsClosed) { Minkowski(pattern, path, solution, true, pathIsClosed); Clipper c; c.AddPaths(solution, ptSubject, true); c.Execute(ctUnion, solution, pftNonZero, pftNonZero); } //------------------------------------------------------------------------------ void TranslatePath(const Path& input, Path& output, const IntPoint delta) { //precondition: input != output output.resize(input.size()); for (size_t i = 0; i < input.size(); ++i) output[i] = IntPoint(input[i].X + delta.X, input[i].Y + delta.Y); } //------------------------------------------------------------------------------ void MinkowskiSum(const Path& pattern, const Paths& paths, Paths& solution, bool pathIsClosed) { Clipper c; for (size_t i = 0; i < paths.size(); ++i) { Paths tmp; Minkowski(pattern, paths[i], tmp, true, pathIsClosed); c.AddPaths(tmp, ptSubject, true); if (pathIsClosed) { Path tmp2; TranslatePath(paths[i], tmp2, pattern[0]); c.AddPath(tmp2, ptClip, true); } } c.Execute(ctUnion, solution, pftNonZero, pftNonZero); } //------------------------------------------------------------------------------ void MinkowskiDiff(const Path& poly1, const Path& poly2, Paths& solution) { Minkowski(poly1, poly2, solution, false, true); Clipper c; c.AddPaths(solution, ptSubject, true); c.Execute(ctUnion, solution, pftNonZero, pftNonZero); } //------------------------------------------------------------------------------ enum NodeType {ntAny, ntOpen, ntClosed}; void AddPolyNodeToPaths(const PolyNode& polynode, NodeType nodetype, Paths& paths) { bool match = true; if (nodetype == ntClosed) match = !polynode.IsOpen(); else if (nodetype == ntOpen) return; if (!polynode.Contour.empty() && match) paths.push_back(polynode.Contour); for (int i = 0; i < polynode.ChildCount(); ++i) AddPolyNodeToPaths(*polynode.Childs[i], nodetype, paths); } //------------------------------------------------------------------------------ void PolyTreeToPaths(const PolyTree& polytree, Paths& paths) { paths.resize(0); paths.reserve(polytree.Total()); AddPolyNodeToPaths(polytree, ntAny, paths); } //------------------------------------------------------------------------------ void ClosedPathsFromPolyTree(const PolyTree& polytree, Paths& paths) { paths.resize(0); paths.reserve(polytree.Total()); AddPolyNodeToPaths(polytree, ntClosed, paths); } //------------------------------------------------------------------------------ void OpenPathsFromPolyTree(PolyTree& polytree, Paths& paths) { paths.resize(0); paths.reserve(polytree.Total()); //Open paths are top level only, so ... for (int i = 0; i < polytree.ChildCount(); ++i) if (polytree.Childs[i]->IsOpen()) paths.push_back(polytree.Childs[i]->Contour); } //------------------------------------------------------------------------------ std::ostream& operator <<(std::ostream &s, const IntPoint &p) { s << "(" << p.X << "," << p.Y << ")"; return s; } //------------------------------------------------------------------------------ std::ostream& operator <<(std::ostream &s, const Path &p) { if (p.empty()) return s; Path::size_type last = p.size() -1; for (Path::size_type i = 0; i < last; i++) s << "(" << p[i].X << "," << p[i].Y << "), "; s << "(" << p[last].X << "," << p[last].Y << ")\n"; return s; } //------------------------------------------------------------------------------ std::ostream& operator <<(std::ostream &s, const Paths &p) { for (Paths::size_type i = 0; i < p.size(); i++) s << p[i]; s << "\n"; return s; } //------------------------------------------------------------------------------ } //ClipperLib namespace

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