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PrusaSlicer-NonPlainar/xs/src/clipper.cpp

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/*******************************************************************************
* *
* Author : Angus Johnson *
* Version : 6.2.9 *
* Date : 16 February 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>
#include <assert.h>
#include <Shiny/Shiny.h>
#include <libslic3r/Int128.hpp>
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))
// Output polygon.
struct OutRec {
int Idx;
bool IsHole;
bool IsOpen;
//The 'FirstLeft' field points to another OutRec that contains or is the
//'parent' of OutRec. It is 'first left' because the ActiveEdgeList (AEL) is
//parsed left from the current edge (owning OutRec) until the owner OutRec
//is found. This field simplifies sorting the polygons into a tree structure
//which reflects the parent/child relationships of all polygons.
//This field should be renamed Parent, and will be later.
OutRec *FirstLeft;
// Used only by void Clipper::BuildResult2(PolyTree& polytree)
PolyNode *PolyNd;
// Linked list of output points, dynamically allocated.
OutPt *Pts;
OutPt *BottomPt;
};
//------------------------------------------------------------------------------
inline cInt Round(double val)
{
return static_cast<cInt>((val < 0) ? (val - 0.5) : (val + 0.5));
}
//------------------------------------------------------------------------------
// PolyTree methods ...
//------------------------------------------------------------------------------
int PolyTree::Total() const
{
int result = (int)AllNodes.size();
//with negative offsets, ignore the hidden outer polygon ...
if (result > 0 && Childs.front() != &AllNodes.front()) result--;
return result;
}
//------------------------------------------------------------------------------
// PolyNode methods ...
//------------------------------------------------------------------------------
void PolyNode::AddChild(PolyNode& child)
{
unsigned cnt = (unsigned)Childs.size();
Childs.push_back(&child);
child.Parent = this;
child.Index = cnt;
}
//------------------------------------------------------------------------------
// Edge delimits a hole if it has an odd number of parent loops.
bool PolyNode::IsHole() const
{
bool result = true;
PolyNode* node = Parent;
while (node)
{
result = !result;
node = node->Parent;
}
return result;
}
//------------------------------------------------------------------------------
// Miscellaneous global functions
//------------------------------------------------------------------------------
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 OutRec &outRec)
{
OutPt *op = outRec.Pts;
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 != outRec.Pts);
return a * 0.5;
}
//------------------------------------------------------------------------------
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 && ((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;
}
//------------------------------------------------------------------------------
// Called by Poly2ContainsPoly1()
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;
do
{
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;
} while (startOp != op);
return result;
}
//------------------------------------------------------------------------------
// This is potentially very expensive! O(n^2)!
bool Poly2ContainsPoly1(OutPt *OutPt1, OutPt *OutPt2)
{
PROFILE_FUNC();
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;
}
//----------------------------------------------------------------------
inline bool SlopesEqual(const cInt dx1, const cInt dy1, const cInt dx2, const cInt dy2, bool UseFullInt64Range) {
return (UseFullInt64Range) ?
// |dx1| < 2^63, |dx2| < 2^63 etc,
Int128::sign_determinant_2x2_filtered(dx1, dy1, dx2, dy2) == 0 :
// Int128::sign_determinant_2x2(dx1, dy1, dx2, dy2) == 0 :
// |dx1| < 2^31, |dx2| < 2^31 etc,
// therefore the following computation could be done with 64bit arithmetics.
dy1 * dx2 == dx1 * dy2;
}
inline bool SlopesEqual(const TEdge &e1, const TEdge &e2, bool UseFullInt64Range)
{ return SlopesEqual(e1.Delta.X, e1.Delta.Y, e2.Delta.X, e2.Delta.Y, UseFullInt64Range); }
inline bool SlopesEqual(const IntPoint &pt1, const IntPoint &pt2, const IntPoint &pt3, bool UseFullInt64Range)
{ return SlopesEqual(pt1.X-pt2.X, pt1.Y-pt2.Y, pt2.X-pt3.X, pt2.Y-pt3.Y, UseFullInt64Range); }
inline bool SlopesEqual(const IntPoint &pt1, const IntPoint &pt2, const IntPoint &pt3, const IntPoint &pt4, bool UseFullInt64Range)
{ return SlopesEqual(pt1.X-pt2.X, pt1.Y-pt2.Y, pt3.X-pt4.X, pt3.Y-pt4.Y, UseFullInt64Range); }
//------------------------------------------------------------------------------
inline bool IsHorizontal(TEdge &e)
{
return e.Delta.Y == 0;
}
//------------------------------------------------------------------------------
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 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.Delta.X == 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.Delta.X == 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);
ip.X = (std::fabs(Edge1.Dx) < std::fabs(Edge2.Dx)) ?
Round(Edge1.Dx * q + b1) :
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);
}
}
//------------------------------------------------------------------------------
// Reverse a linked loop of points representing a closed polygon.
// This has a time complexity of O(n)
void ReversePolyPtLinks(OutPt *pp)
{
if (!pp) return;
OutPt *pp1 = pp;
do {
OutPt *pp2 = pp1->Next;
pp1->Next = pp1->Prev;
pp1->Prev = pp2;
pp1 = pp2;
} while( pp1 != pp );
}
//------------------------------------------------------------------------------
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;
}
e.Delta.X = (e.Top.X - e.Bot.X);
e.Delta.Y = (e.Top.Y - e.Bot.Y);
if (e.Delta.Y == 0) e.Dx = HORIZONTAL;
else e.Dx = (double)(e.Delta.X) / e.Delta.Y;
e.PolyTyp = Pt;
}
//------------------------------------------------------------------------------
// Called from ClipperBase::AddPathInternal() to remove collinear and duplicate points.
inline 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
}
//------------------------------------------------------------------------------
bool GetOverlapSegment(IntPoint pt1a, IntPoint pt1b, IntPoint pt2a,
IntPoint pt2b, IntPoint &pt1, IntPoint &pt2)
{
//precondition: segments are Collinear.
if (std::abs(pt1a.X - pt1b.X) > std::abs(pt1a.Y - pt1b.Y))
{
if (pt1a.X > pt1b.X) std::swap(pt1a, pt1b);
if (pt2a.X > pt2b.X) std::swap(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) std::swap(pt1a, pt1b);
if (pt2a.Y < pt2b.Y) std::swap(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));
return (dx1p >= dx2p && dx1p >= dx2n) || (dx1n >= dx2p && dx1n >= dx2n);
}
//------------------------------------------------------------------------------
// Called by GetLowermostRec()
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 ...
//------------------------------------------------------------------------------
// Called from ClipperBase::AddPath() to verify the scale of the input polygon coordinates.
inline 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);
}
}
//------------------------------------------------------------------------------
// Called from ClipperBase::AddPath() to construct the Local Minima List.
// Find a local minimum edge on the path starting with E.
inline 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;
}
//------------------------------------------------------------------------------
// Called from ClipperBase::AddPath().
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;
LocalMinimum 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)
{
PROFILE_FUNC();
// Remove duplicate end point from a closed input path.
// Remove duplicate points from the end of the input path.
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;
// Allocate a new edge array.
std::vector<TEdge> edges(highI + 1);
// Fill in the edge array.
bool result = AddPathInternal(pg, highI, PolyTyp, Closed, edges.data());
if (result)
// Success, remember the edge array.
m_edges.emplace_back(std::move(edges));
return result;
}
bool ClipperBase::AddPaths(const Paths &ppg, PolyType PolyTyp, bool Closed)
{
PROFILE_FUNC();
std::vector<int> num_edges(ppg.size(), 0);
int num_edges_total = 0;
for (size_t i = 0; i < ppg.size(); ++ i) {
const Path &pg = ppg[i];
// Remove duplicate end point from a closed input path.
// Remove duplicate points from the end of the input path.
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))
highI = -1;
num_edges[i] = highI + 1;
num_edges_total += highI + 1;
}
if (num_edges_total == 0)
return false;
// Allocate a new edge array.
std::vector<TEdge> edges(num_edges_total);
// Fill in the edge array.
bool result = false;
TEdge *p_edge = edges.data();
for (Paths::size_type i = 0; i < ppg.size(); ++i)
if (num_edges[i]) {
bool res = AddPathInternal(ppg[i], num_edges[i] - 1, PolyTyp, Closed, p_edge);
if (res) {
p_edge += num_edges[i];
result = true;
}
}
if (result)
// At least some edges were generated. Remember the edge array.
m_edges.emplace_back(std::move(edges));
return result;
}
bool ClipperBase::AddPathInternal(const Path &pg, int highI, PolyType PolyTyp, bool Closed, TEdge* edges)
{
PROFILE_FUNC();
#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
assert(highI >= 0 && highI < pg.size());
//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(...)
{
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)))
{
return false;
}
if (!Closed)
{
m_HasOpenPaths = true;
eStart->Prev->OutIdx = Skip;
}
//3. Do second stage of edge initialization ...
// IsFlat means all vertices have the same Y coordinate.
bool IsFlat = true;
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)
{
return false;
}
E->Prev->OutIdx = Skip;
LocalMinimum 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);
return true;
}
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;
// Find local minima and store them into a Local Minima List.
// Multiple Local Minima could be created for a single path.
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 ...
LocalMinimum 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
}
locMin.LeftBound->Side = esLeft;
locMin.RightBound->Side = esRight;
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;
}
//------------------------------------------------------------------------------
void ClipperBase::Clear()
{
PROFILE_FUNC();
m_MinimaList.clear();
m_edges.clear();
m_UseFullRange = false;
m_HasOpenPaths = false;
}
//------------------------------------------------------------------------------
// Initialize the Local Minima List:
// Sort the LML entries, initialize the left / right bound edges of each Local Minima.
void ClipperBase::Reset()
{
PROFILE_FUNC();
if (m_MinimaList.empty()) return; //ie nothing to process
std::sort(m_MinimaList.begin(), m_MinimaList.end(), [](const LocalMinimum& lm1, const LocalMinimum& lm2){ return lm1.Y < lm2.Y; });
//reset all edges ...
for (LocalMinimum &lm : m_MinimaList) {
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;
}
}
}
//------------------------------------------------------------------------------
// Get bounds of the edges referenced by the Local Minima List.
// Returns (0,0,0,0) for an empty rectangle.
IntRect ClipperBase::GetBounds()
{
PROFILE_FUNC();
IntRect result;
auto 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())
{
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;
}
//------------------------------------------------------------------------------
// TClipper methods ...
//------------------------------------------------------------------------------
Clipper::Clipper(int initOptions) :
ClipperBase(),
m_OutPtsFree(nullptr),
m_OutPtsChunkSize(32),
m_OutPtsChunkLast(32),
m_ActiveEdges(nullptr),
m_SortedEdges(nullptr)
{
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
}
//------------------------------------------------------------------------------
void Clipper::Reset()
{
PROFILE_FUNC();
ClipperBase::Reset();
m_Scanbeam = std::priority_queue<cInt>();
m_Maxima.clear();
m_ActiveEdges = 0;
m_SortedEdges = 0;
for (auto lm = m_MinimaList.rbegin(); lm != m_MinimaList.rend(); ++lm)
m_Scanbeam.push(lm->Y);
}
//------------------------------------------------------------------------------
bool Clipper::Execute(ClipType clipType, Paths &solution,
PolyFillType subjFillType, PolyFillType clipFillType)
{
PROFILE_FUNC();
if (m_HasOpenPaths)
throw clipperException("Error: PolyTree struct is needed for open path clipping.");
solution.resize(0);
m_SubjFillType = subjFillType;
m_ClipFillType = clipFillType;
m_ClipType = clipType;
m_UsingPolyTree = false;
bool succeeded = ExecuteInternal();
if (succeeded) BuildResult(solution);
DisposeAllOutRecs();
return succeeded;
}
//------------------------------------------------------------------------------
bool Clipper::Execute(ClipType clipType, PolyTree& polytree,
PolyFillType subjFillType, PolyFillType clipFillType)
{
PROFILE_FUNC();
m_SubjFillType = subjFillType;
m_ClipFillType = clipFillType;
m_ClipType = clipType;
m_UsingPolyTree = true;
bool succeeded = ExecuteInternal();
if (succeeded) BuildResult2(polytree);
DisposeAllOutRecs();
return succeeded;
}
//------------------------------------------------------------------------------
bool Clipper::ExecuteInternal()
{
PROFILE_FUNC();
bool succeeded = true;
try {
PROFILE_BLOCK(Clipper_ExecuteInternal_Process);
Reset();
if (m_MinimaList.empty()) return true;
cInt botY = m_Scanbeam.top();
do { m_Scanbeam.pop(); } while (! m_Scanbeam.empty() && botY == m_Scanbeam.top());
do {
InsertLocalMinimaIntoAEL(botY);
ProcessHorizontals();
m_GhostJoins.clear();
if (m_Scanbeam.empty()) break;
cInt topY = m_Scanbeam.top();
do { m_Scanbeam.pop(); } while (! m_Scanbeam.empty() && topY == m_Scanbeam.top());
succeeded = ProcessIntersections(topY);
if (!succeeded) break;
ProcessEdgesAtTopOfScanbeam(topY);
botY = topY;
} while (!m_Scanbeam.empty() || !m_MinimaList.empty());
}
catch(...)
{
succeeded = false;
}
if (succeeded)
{
PROFILE_BLOCK(Clipper_ExecuteInternal_Fix);
//fix orientations ...
//FIXME Vojtech: Does it not invalidate the loop hierarchy maintained as OutRec::FirstLeft pointers?
//FIXME Vojtech: The area is calculated with floats, it may not be numerically stable!
{
PROFILE_BLOCK(Clipper_ExecuteInternal_Fix_orientations);
for (OutRec *outRec : m_PolyOuts)
if (outRec->Pts && !outRec->IsOpen && (outRec->IsHole ^ m_ReverseOutput) == (Area(*outRec) > 0))
ReversePolyPtLinks(outRec->Pts);
}
JoinCommonEdges();
//unfortunately FixupOutPolygon() must be done after JoinCommonEdges()
{
PROFILE_BLOCK(Clipper_ExecuteInternal_Fix_fixup);
for (OutRec *outRec : m_PolyOuts)
if (outRec->Pts) {
if (outRec->IsOpen)
// Removes duplicate points.
FixupOutPolyline(*outRec);
else
// Removes duplicate points and simplifies consecutive parallel edges by removing the middle vertex.
FixupOutPolygon(*outRec);
}
}
// For each polygon, search for exactly duplicate non-successive points.
// If such a point is found, the loop is split into two pieces.
// Search for the duplicate points is O(n^2)!
// http://www.angusj.com/delphi/clipper/documentation/Docs/Units/ClipperLib/Classes/Clipper/Properties/StrictlySimple.htm
if (m_StrictSimple) DoSimplePolygons();
}
m_Joins.clear();
m_GhostJoins.clear();
return succeeded;
}
//------------------------------------------------------------------------------
OutPt* Clipper::AllocateOutPt()
{
OutPt *pt;
if (m_OutPtsFree) {
// Recycle some of the already released points.
pt = m_OutPtsFree;
m_OutPtsFree = pt->Next;
} else if (m_OutPtsChunkLast < m_OutPtsChunkSize) {
// Get a point from the last chunk.
pt = m_OutPts.back() + (m_OutPtsChunkLast ++);
} else {
// The last chunk is full. Allocate a new one.
m_OutPts.push_back(new OutPt[m_OutPtsChunkSize]);
m_OutPtsChunkLast = 1;
pt = m_OutPts.back();
}
return pt;
}
void Clipper::DisposeAllOutRecs()
{
for (OutPt *pts : m_OutPts)
delete[] pts;
for (OutRec *rec : m_PolyOuts)
delete rec;
m_OutPts.clear();
m_OutPtsFree = nullptr;
m_OutPtsChunkLast = m_OutPtsChunkSize;
m_PolyOuts.clear();
}
//------------------------------------------------------------------------------
void Clipper::SetWindingCount(TEdge &edge) const
{
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)
{
edge.WindCnt = (edge.WindDelta == 0 ? 1 : 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 (std::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::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 (std::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;
}
}
//------------------------------------------------------------------------------
// Called from Clipper::InsertLocalMinimaIntoAEL() and Clipper::IntersectEdges().
OutPt* Clipper::AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &Pt)
{
PROFILE_FUNC();
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 &&
(TopX(*prevE, Pt.Y) == TopX(*e, Pt.Y)) &&
SlopesEqual(*e, *prevE, m_UseFullRange) &&
(e->WindDelta != 0) && (prevE->WindDelta != 0))
{
OutPt* outPt = AddOutPt(prevE, Pt);
m_Joins.emplace_back(Join(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;
}
}
//------------------------------------------------------------------------------
void Clipper::CopyAELToSEL()
{
TEdge* e = m_ActiveEdges;
m_SortedEdges = e;
while ( e )
{
e->PrevInSEL = e->PrevInAEL;
e->NextInSEL = e->NextInAEL;
e = e->NextInAEL;
}
}
//------------------------------------------------------------------------------
// Called from Clipper::ExecuteInternal()
void Clipper::InsertLocalMinimaIntoAEL(const cInt botY)
{
PROFILE_FUNC();
while (!m_MinimaList.empty() && m_MinimaList.back().Y == botY)
{
TEdge* lb = m_MinimaList.back().LeftBound;
TEdge* rb = m_MinimaList.back().RightBound;
m_MinimaList.pop_back();
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);
m_Scanbeam.push(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);
m_Scanbeam.push(lb->Top.Y);
}
if (rb)
{
if(IsHorizontal(*rb)) AddEdgeToSEL(rb);
else m_Scanbeam.push(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 (Join &jr : m_GhostJoins)
//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))
m_Joins.emplace_back(Join(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, *lb, m_UseFullRange) &&
(lb->WindDelta != 0) && (lb->PrevInAEL->WindDelta != 0))
{
OutPt *Op2 = AddOutPt(lb->PrevInAEL, lb->Bot);
m_Joins.emplace_back(Join(Op1, Op2, lb->Top));
}
if(lb->NextInAEL != rb)
{
if (rb->OutIdx >= 0 && rb->PrevInAEL->OutIdx >= 0 &&
SlopesEqual(*rb->PrevInAEL, *rb, m_UseFullRange) &&
(rb->WindDelta != 0) && (rb->PrevInAEL->WindDelta != 0))
{
OutPt *Op2 = AddOutPt(rb->PrevInAEL, rb->Bot);
m_Joins.emplace_back(Join(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::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;
}
//------------------------------------------------------------------------------
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) && std::abs(e2->WindCnt) == 1 &&
(m_ClipType != ctUnion || e2->WindCnt2 == 0))
{
AddOutPt(e1, Pt);
if (e1Contributing) e1->OutIdx = Unassigned;
}
else if ((e2->WindDelta == 0) && (std::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 = std::abs(e1->WindCnt);
}
switch(e2FillType)
{
case pftPositive: e2Wc = e2->WindCnt; break;
case pftNegative: e2Wc = -e2->WindCnt; break;
default: e2Wc = std::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);
std::swap(e1->Side, e2->Side);
std::swap(e1->OutIdx, e2->OutIdx);
}
}
else if ( e1Contributing )
{
if (e2Wc == 0 || e2Wc == 1)
{
AddOutPt(e1, Pt);
std::swap(e1->Side, e2->Side);
std::swap(e1->OutIdx, e2->OutIdx);
}
}
else if ( e2Contributing )
{
if (e1Wc == 0 || e1Wc == 1)
{
AddOutPt(e2, Pt);
std::swap(e1->Side, e2->Side);
std::swap(e1->OutIdx, e2->OutIdx);
}
}
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 = std::abs(e1->WindCnt2);
}
switch (e2FillType2)
{
case pftPositive: e2Wc2 = e2->WindCnt2; break;
case pftNegative: e2Wc2 = -e2->WindCnt2; break;
default: e2Wc2 = std::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
std::swap(e1->Side, e2->Side);
}
}
//------------------------------------------------------------------------------
void Clipper::SetHoleState(TEdge *e, OutRec *outrec) const
{
bool IsHole = false;
TEdge *e2 = e->PrevInAEL;
while (e2)
{
if (e2->OutIdx >= 0 && e2->WindDelta != 0)
{
IsHole = !IsHole;
if (! outrec->FirstLeft)
outrec->FirstLeft = m_PolyOuts[e2->OutIdx];
}
e2 = e2->PrevInAEL;
}
if (IsHole) outrec->IsHole = true;
}
//------------------------------------------------------------------------------
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 Param1RightOfParam2(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) const
{
//get the start and ends of both output polygons ...
OutRec *outRec1 = m_PolyOuts[e1->OutIdx];
OutRec *outRec2 = m_PolyOuts[e2->OutIdx];
OutRec *holeStateRec;
if (Param1RightOfParam2(outRec1, outRec2))
holeStateRec = outRec2;
else if (Param1RightOfParam2(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;
EdgeSide Side;
//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;
}
Side = esLeft;
} 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;
}
Side = esRight;
}
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 = Side;
break;
}
e = e->NextInAEL;
}
outRec2->Idx = outRec1->Idx;
}
//------------------------------------------------------------------------------
OutRec* Clipper::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;
}
//------------------------------------------------------------------------------
OutPt* Clipper::AddOutPt(TEdge *e, const IntPoint &pt)
{
if( e->OutIdx < 0 )
{
OutRec *outRec = CreateOutRec();
outRec->IsOpen = (e->WindDelta == 0);
OutPt* newOp = this->AllocateOutPt();
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 = this->AllocateOutPt();
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()
{
PROFILE_FUNC();
TEdge* horzEdge = m_SortedEdges;
while(horzEdge)
{
DeleteFromSEL(horzEdge);
ProcessHorizontal(horzEdge);
horzEdge = m_SortedEdges;
}
}
//------------------------------------------------------------------------------
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;
}
//------------------------------------------------------------------------------
inline TEdge *GetMaximaPair(TEdge *e)
{
TEdge* result = 0;
if ((e->Next->Top == e->Top) && !e->Next->NextInLML)
result = e->Next;
else if ((e->Prev->Top == e->Top) && !e->Prev->NextInLML)
result = e->Prev;
if (result && (result->OutIdx == Skip ||
//result is false if both NextInAEL & PrevInAEL are nil & not horizontal ...
(result->NextInAEL == result->PrevInAEL && !IsHorizontal(*result))))
return 0;
return result;
}
//------------------------------------------------------------------------------
void Clipper::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 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;
}
//------------------------------------------------------------------------------
inline 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->OutIdx >= 0 && m_PolyOuts[horzEdge->OutIdx]->IsOpen);
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);
std::vector<cInt>::const_iterator maxIt;
std::vector<cInt>::const_reverse_iterator maxRit;
if (!m_Maxima.empty())
{
//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 = (dir == dLeftToRight) ? horzEdge->NextInAEL : horzEdge->PrevInAEL;
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.empty())
{
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);
m_Joins.emplace_back(Join(op2, op1, eNextHorz->Top));
}
eNextHorz = eNextHorz->NextInSEL;
}
m_GhostJoins.emplace_back(Join(op1, 0, 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 = (dir == dLeftToRight) ? e->NextInAEL : e->PrevInAEL;
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);
m_Joins.emplace_back(Join(op2, op1, eNextHorz->Top));
}
eNextHorz = eNextHorz->NextInSEL;
}
m_GhostJoins.emplace_back(Join(op1, 0, 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);
m_Joins.emplace_back(Join(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);
m_Joins.emplace_back(Join(op1, op2, horzEdge->Top));
}
}
else
UpdateEdgeIntoAEL(horzEdge);
}
else
{
if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Top);
DeleteFromAEL(horzEdge);
}
}
//------------------------------------------------------------------------------
void Clipper::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))
m_Scanbeam.push(e->Top.Y);
}
//------------------------------------------------------------------------------
bool Clipper::ProcessIntersections(const cInt topY)
{
PROFILE_FUNC();
if( !m_ActiveEdges ) return true;
try {
BuildIntersectList(topY);
size_t IlSize = m_IntersectList.size();
if (IlSize == 0) return true;
if (IlSize == 1 || FixupIntersectionOrder()) {
for (IntersectNode &iNode : m_IntersectList) {
IntersectEdges( iNode.Edge1, iNode.Edge2, iNode.Pt);
SwapPositionsInAEL( iNode.Edge1 , iNode.Edge2 );
}
m_IntersectList.clear();
}
else return false;
}
catch(...)
{
m_SortedEdges = 0;
m_IntersectList.clear();
throw clipperException("ProcessIntersections error");
}
m_SortedEdges = 0;
return true;
}
//------------------------------------------------------------------------------
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);
m_IntersectList.emplace_back(IntersectNode(e, eNext, Pt));
SwapPositionsInSEL(e, eNext);
isModified = true;
}
else
e = eNext;
}
if( e->PrevInSEL ) e->PrevInSEL->NextInSEL = 0;
else break;
}
while ( isModified );
m_SortedEdges = 0; //important
}
//------------------------------------------------------------------------------
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(), [](const IntersectNode &node1, const IntersectNode &node2) { return node2.Pt.Y < node1.Pt.Y; });
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 = GetMaximaPair(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)
{
PROFILE_FUNC();
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 = GetMaximaPair(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);
m_Joins.emplace_back(Join(op, op2, pt)); //StrictlySimple (type-3) join
}
}
e = e->NextInAEL;
}
}
//3. Process horizontals at the Top of the scanbeam ...
std::sort(m_Maxima.begin(), m_Maxima.end());
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, *ePrev, m_UseFullRange) &&
(e->WindDelta != 0) && (ePrev->WindDelta != 0))
{
OutPt* op2 = AddOutPt(ePrev, e->Bot);
m_Joins.emplace_back(Join(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, *eNext, m_UseFullRange) &&
(e->WindDelta != 0) && (eNext->WindDelta != 0))
{
OutPt* op2 = AddOutPt(eNext, e->Bot);
m_Joins.emplace_back(Join(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;
this->DisposeOutPt(pp);
pp = tmpPP;
}
}
if (pp == pp->Prev)
{
this->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 = nullptr;
outrec.BottomPt = nullptr;
OutPt *pp = outrec.Pts;
bool preserveCol = m_PreserveCollinear || m_StrictSimple;
for (;;)
{
if (pp->Prev == pp || pp->Prev == pp->Next)
{
// Empty loop or a stick. Release the polygon.
this->DisposeOutPts(pp);
outrec.Pts = nullptr;
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 = nullptr;
OutPt *tmp = pp;
pp->Prev->Next = pp->Next;
pp->Next->Prev = pp->Prev;
pp = pp->Prev;
this->DisposeOutPt(tmp);
}
else if (pp == lastOK) break;
else
{
if (!lastOK) lastOK = pp;
pp = pp->Next;
}
}
outrec.Pts = pp;
}
//------------------------------------------------------------------------------
// Count the number of points in a closed linked loop starting with Pts.
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 (OutRec* outRec : m_PolyOuts)
{
assert(! outRec->IsOpen);
if (!outRec->Pts) continue;
Path pg;
OutPt* p = outRec->Pts->Prev;
int cnt = PointCount(p);
if (cnt < 2) continue;
pg.reserve(cnt);
for (int i = 0; i < cnt; ++i)
{
pg.emplace_back(p->Pt);
p = p->Prev;
}
polys.emplace_back(std::move(pg));
}
}
//------------------------------------------------------------------------------
void Clipper::BuildResult2(PolyTree& polytree)
{
polytree.Clear();
polytree.AllNodes.reserve(m_PolyOuts.size());
//add each output polygon/contour to polytree ...
for (OutRec* outRec : m_PolyOuts)
{
int cnt = PointCount(outRec->Pts);
if ((outRec->IsOpen && cnt < 2) || (!outRec->IsOpen && cnt < 3))
// Ignore an invalid output loop or a polyline.
continue;
//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)) {
OutRec* orfl = outRec->FirstLeft;
while (orfl && ((orfl->IsHole == outRec->IsHole) || !orfl->Pts))
orfl = orfl->FirstLeft;
outRec->FirstLeft = orfl;
}
//nb: polytree takes ownership of all the PolyNodes
polytree.AllNodes.emplace_back(PolyNode());
PolyNode* pn = &polytree.AllNodes.back();
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.emplace_back(op->Pt);
op = op->Prev;
}
}
//fixup PolyNode links etc ...
polytree.Childs.reserve(m_PolyOuts.size());
for (OutRec* outRec : m_PolyOuts)
{
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);
}
}
//------------------------------------------------------------------------------
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;
}
//------------------------------------------------------------------------------
// Make all points of outrec point to outrec.Idx
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* Clipper::DupOutPt(OutPt* outPt, bool InsertAfter)
{
OutPt* result = this->AllocateOutPt();
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 Clipper::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 = this->DupOutPt(op1, !DiscardLeft);
if (op1b->Pt != Pt)
{
op1 = op1b;
op1->Pt = Pt;
op1b = this->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 = this->DupOutPt(op1, DiscardLeft);
if (op1b->Pt != Pt)
{
op1 = op1b;
op1->Pt = Pt;
op1b = this->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 = this->DupOutPt(op2, !DiscardLeft);
if (op2b->Pt != Pt)
{
op2 = op2b;
op2->Pt = Pt;
op2b = this->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 = this->DupOutPt(op2, DiscardLeft);
if (op2b->Pt != Pt)
{
op2 = op2b;
op2->Pt = Pt;
op2b = this->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 = this->DupOutPt(op1, false);
op2b = this->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 = this->DupOutPt(op1, true);
op2b = this->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 = this->DupOutPt(op1, false);
op2b = this->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 = this->DupOutPt(op1, true);
op2b = this->DupOutPt(op2, false);
op1->Next = op2;
op2->Prev = op1;
op1b->Prev = op2b;
op2b->Next = op1b;
j->OutPt1 = op1;
j->OutPt2 = op1b;
return true;
}
}
}
//----------------------------------------------------------------------
// This is potentially very expensive! O(n^3)!
void Clipper::FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec) const
{
PROFILE_FUNC();
//tests if NewOutRec contains the polygon before reassigning FirstLeft
for (OutRec *outRec : m_PolyOuts)
{
if (!outRec->Pts || !outRec->FirstLeft) continue;
OutRec* firstLeft = outRec->FirstLeft;
// Skip empty polygons.
while (firstLeft && !firstLeft->Pts) firstLeft = firstLeft->FirstLeft;
if (firstLeft == OldOutRec && Poly2ContainsPoly1(outRec->Pts, NewOutRec->Pts))
outRec->FirstLeft = NewOutRec;
}
}
//----------------------------------------------------------------------
void Clipper::FixupFirstLefts2(OutRec* OldOutRec, OutRec* NewOutRec) const
{
//reassigns FirstLeft WITHOUT testing if NewOutRec contains the polygon
for (OutRec *outRec : m_PolyOuts)
if (outRec->FirstLeft == OldOutRec) outRec->FirstLeft = NewOutRec;
}
//----------------------------------------------------------------------
void Clipper::JoinCommonEdges()
{
PROFILE_FUNC();
for (Join &join : m_Joins)
{
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 (Param1RightOfParam2(outRec1, outRec2)) holeStateRec = outRec2;
else if (Param1RightOfParam2(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);
//We now need to check every OutRec.FirstLeft pointer. If it points
//to OutRec1 it may need to point to OutRec2 instead ...
if (m_UsingPolyTree)
for (size_t j = 0; j < m_PolyOuts.size() - 1; j++)
{
OutRec* oRec = m_PolyOuts[j];
OutRec* firstLeft = oRec->FirstLeft;
while (firstLeft && !firstLeft->Pts) firstLeft = firstLeft->FirstLeft;
if (!oRec->Pts || firstLeft != outRec1 ||
oRec->IsHole == outRec1->IsHole) continue;
if (Poly2ContainsPoly1(oRec->Pts, join.OutPt2))
oRec->FirstLeft = outRec2;
}
if (Poly2ContainsPoly1(outRec2->Pts, outRec1->Pts))
{
//outRec2 is contained by outRec1 ...
outRec2->IsHole = !outRec1->IsHole;
outRec2->FirstLeft = outRec1;
// For each m_PolyOuts, replace FirstLeft from outRec2 to 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))
{
//outRec1 is contained by outRec2 ...
outRec2->IsHole = outRec1->IsHole;
outRec1->IsHole = !outRec2->IsHole;
outRec2->FirstLeft = outRec1->FirstLeft;
outRec1->FirstLeft = outRec2;
// For each m_PolyOuts, replace FirstLeft from outRec1 to 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
// For each polygon of m_PolyOuts, replace FirstLeft from outRec1 to outRec2 if the polygon is inside outRec2.
//FIXME This is potentially very expensive! O(n^3)!
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;
// For each m_PolyOuts, replace FirstLeft from outRec2 to outRec1.
if (m_UsingPolyTree) FixupFirstLefts2(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
//------------------------------------------------------------------------------
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 ...
bool has_shortest_edge_length = ShortestEdgeLength > 0.;
double shortest_edge_length2 = has_shortest_edge_length ? ShortestEdgeLength * ShortestEdgeLength : 0.;
if (endType == etClosedLine || endType == etClosedPolygon)
for (; highI > 0; -- highI) {
bool same = false;
if (has_shortest_edge_length) {
double dx = double(path[highI].X - path[0].X);
double dy = double(path[highI].Y - path[0].Y);
same = dx*dx + dy*dy < shortest_edge_length2;
} else
same = path[0] == path[highI];
if (! same)
break;
}
newNode->Contour.reserve(highI + 1);
newNode->Contour.push_back(path[0]);
int j = 0, k = 0;
for (int i = 1; i <= highI; i++) {
bool same = false;
if (has_shortest_edge_length) {
double dx = double(path[i].X - newNode->Contour[j].X);
double dy = double(path[i].Y - newNode->Contour[j].Y);
same = dx*dx + dy*dy < shortest_edge_length2;
} else
same = newNode->Contour[j] == path[i];
if (same)
continue;
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 (const Path &path : paths)
AddPath(path, 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(Round(m_srcPoly[j].X + m_normals[j].X *
delta), Round(m_srcPoly[j].Y + m_normals[j].Y * delta));
m_destPoly.push_back(pt1);
pt1 = IntPoint(Round(m_srcPoly[j].X - m_normals[j].X *
delta), 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(Round(m_srcPoly[0].X - m_normals[0].X * delta),
Round(m_srcPoly[0].Y - m_normals[0].Y * delta));
m_destPoly.push_back(pt1);
pt1 = IntPoint(Round(m_srcPoly[0].X + m_normals[0].X * delta),
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
//------------------------------------------------------------------------------
// Called by Clipper::ExecuteInternal()
// For each polygon, search for exactly duplicate non-successive points.
// If such a point is found, the loop is split into two pieces.
// Search for the duplicate points is O(n^2)!
// http://www.angusj.com/delphi/clipper/documentation/Docs/Units/ClipperLib/Classes/Clipper/Properties/StrictlySimple.htm
void Clipper::DoSimplePolygons()
{
PROFILE_FUNC();
size_t 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;
// For each m_PolyOuts, replace FirstLeft from outRec2 to 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;
// For each m_PolyOuts, replace FirstLeft from outrec to outrec2.
if (m_UsingPolyTree) FixupFirstLefts2(outrec, outrec2);
}
else
{
//the 2 polygons are separate ...
outrec2->IsHole = outrec->IsHole;
outrec2->FirstLeft = outrec->FirstLeft;
// For each polygon of m_PolyOuts, replace FirstLeft from outrec to outrec2 if the polygon is inside outRec2.
//FIXME This is potentially very expensive! O(n^3)!
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 (x<>,y<>) & (x<>,y<>) is ...
//(y<> - y<>)x + (x<> - x<>)y + (y<> - y<>)x<> - (x<> - x<>)y<> = 0
//A = (y<> - y<>); B = (x<> - x<>); C = (y<> - y<>)x<> - (x<> - x<>)y<>
//perpendicular distance of point (x<>,y<>) = (Ax<41> + By<42> + C)/Sqrt(A<> + B<>)
//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 (std::abs(pt1.X - pt2.X) > std::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;
}
//------------------------------------------------------------------------------
// Simplify a polygon using a linked list of points.
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;
}
std::vector<OutPt> outPts(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;
}
}
//------------------------------------------------------------------------------
void CleanPolygon(Path& poly, double distance)
{
CleanPolygon(poly, poly, distance);
}
//------------------------------------------------------------------------------
void CleanPolygons(const Paths& in_polys, Paths& out_polys, double distance)
{
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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