From 0ee7e3102b6072d2f5a9d157c8afdb99e13624e6 Mon Sep 17 00:00:00 2001 From: smix8 <52464204+smix8@users.noreply.github.com> Date: Thu, 17 Aug 2023 18:32:30 +0200 Subject: Add 2D navigation mesh baking Adds 2D navigation mesh baking. --- thirdparty/clipper2/src/clipper.engine.cpp | 2979 ++++++++++++++++++++++++++++ 1 file changed, 2979 insertions(+) create mode 100644 thirdparty/clipper2/src/clipper.engine.cpp (limited to 'thirdparty/clipper2/src/clipper.engine.cpp') diff --git a/thirdparty/clipper2/src/clipper.engine.cpp b/thirdparty/clipper2/src/clipper.engine.cpp new file mode 100644 index 0000000000..2d61b8aafa --- /dev/null +++ b/thirdparty/clipper2/src/clipper.engine.cpp @@ -0,0 +1,2979 @@ +/******************************************************************************* +* Author : Angus Johnson * +* Date : 19 March 2023 * +* Website : http://www.angusj.com * +* Copyright : Angus Johnson 2010-2023 * +* Purpose : This is the main polygon clipping module * +* License : http://www.boost.org/LICENSE_1_0.txt * +*******************************************************************************/ + +#include +#include +#include +#include +#include +#include + +#include "clipper2/clipper.engine.h" + +// https://github.com/AngusJohnson/Clipper2/discussions/334 +// #discussioncomment-4248602 +#if defined(_MSC_VER) && ( defined(_M_AMD64) || defined(_M_X64) ) +#include +#include +#define fmin(a,b) _mm_cvtsd_f64(_mm_min_sd(_mm_set_sd(a),_mm_set_sd(b))) +#define fmax(a,b) _mm_cvtsd_f64(_mm_max_sd(_mm_set_sd(a),_mm_set_sd(b))) +#define nearbyint(a) _mm_cvtsd_si64(_mm_set_sd(a)) /* Note: expression type is (int64_t) */ +#endif + +namespace Clipper2Lib { + + static const Rect64 invalid_rect = Rect64(false); + + // Every closed path (or polygon) is made up of a series of vertices forming + // edges that alternate between going up (relative to the Y-axis) and going + // down. Edges consecutively going up or consecutively going down are called + // 'bounds' (ie sides if they're simple polygons). 'Local Minima' refer to + // vertices where descending bounds become ascending ones. + + struct Scanline { + int64_t y = 0; + Scanline* next = nullptr; + + explicit Scanline(int64_t y_) : y(y_) {} + }; + + struct HorzSegSorter { + inline bool operator()(const HorzSegment& hs1, const HorzSegment& hs2) + { + if (!hs1.right_op || !hs2.right_op) return (hs1.right_op); + return hs2.left_op->pt.x > hs1.left_op->pt.x; + } + }; + + struct LocMinSorter { + inline bool operator()(const LocalMinima_ptr& locMin1, + const LocalMinima_ptr& locMin2) + { + if (locMin2->vertex->pt.y != locMin1->vertex->pt.y) + return locMin2->vertex->pt.y < locMin1->vertex->pt.y; + else + return locMin2->vertex->pt.x > locMin1->vertex->pt.x; + } + }; + + inline bool IsOdd(int val) + { + return (val & 1) ? true : false; + } + + + inline bool IsHotEdge(const Active& e) + { + return (e.outrec); + } + + + inline bool IsOpen(const Active& e) + { + return (e.local_min->is_open); + } + + + inline bool IsOpenEnd(const Vertex& v) + { + return (v.flags & (VertexFlags::OpenStart | VertexFlags::OpenEnd)) != + VertexFlags::None; + } + + + inline bool IsOpenEnd(const Active& ae) + { + return IsOpenEnd(*ae.vertex_top); + } + + + inline Active* GetPrevHotEdge(const Active& e) + { + Active* prev = e.prev_in_ael; + while (prev && (IsOpen(*prev) || !IsHotEdge(*prev))) + prev = prev->prev_in_ael; + return prev; + } + + inline bool IsFront(const Active& e) + { + return (&e == e.outrec->front_edge); + } + + inline bool IsInvalidPath(OutPt* op) + { + return (!op || op->next == op); + } + + /******************************************************************************* + * Dx: 0(90deg) * + * | * + * +inf (180deg) <--- o ---> -inf (0deg) * + *******************************************************************************/ + + inline double GetDx(const Point64& pt1, const Point64& pt2) + { + double dy = double(pt2.y - pt1.y); + if (dy != 0) + return double(pt2.x - pt1.x) / dy; + else if (pt2.x > pt1.x) + return -std::numeric_limits::max(); + else + return std::numeric_limits::max(); + } + + inline int64_t TopX(const Active& ae, const int64_t currentY) + { + if ((currentY == ae.top.y) || (ae.top.x == ae.bot.x)) return ae.top.x; + else if (currentY == ae.bot.y) return ae.bot.x; + else return ae.bot.x + static_cast(nearbyint(ae.dx * (currentY - ae.bot.y))); + // nb: std::nearbyint (or std::round) substantially *improves* performance here + // as it greatly improves the likelihood of edge adjacency in ProcessIntersectList(). + } + + + inline bool IsHorizontal(const Active& e) + { + return (e.top.y == e.bot.y); + } + + + inline bool IsHeadingRightHorz(const Active& e) + { + return e.dx == -std::numeric_limits::max(); + } + + + inline bool IsHeadingLeftHorz(const Active& e) + { + return e.dx == std::numeric_limits::max(); + } + + + inline void SwapActives(Active*& e1, Active*& e2) + { + Active* e = e1; + e1 = e2; + e2 = e; + } + + inline PathType GetPolyType(const Active& e) + { + return e.local_min->polytype; + } + + inline bool IsSamePolyType(const Active& e1, const Active& e2) + { + return e1.local_min->polytype == e2.local_min->polytype; + } + + inline void SetDx(Active& e) + { + e.dx = GetDx(e.bot, e.top); + } + + inline Vertex* NextVertex(const Active& e) + { + if (e.wind_dx > 0) + return e.vertex_top->next; + else + return e.vertex_top->prev; + } + + //PrevPrevVertex: useful to get the (inverted Y-axis) top of the + //alternate edge (ie left or right bound) during edge insertion. + inline Vertex* PrevPrevVertex(const Active& ae) + { + if (ae.wind_dx > 0) + return ae.vertex_top->prev->prev; + else + return ae.vertex_top->next->next; + } + + + inline Active* ExtractFromSEL(Active* ae) + { + Active* res = ae->next_in_sel; + if (res) + res->prev_in_sel = ae->prev_in_sel; + ae->prev_in_sel->next_in_sel = res; + return res; + } + + + inline void Insert1Before2InSEL(Active* ae1, Active* ae2) + { + ae1->prev_in_sel = ae2->prev_in_sel; + if (ae1->prev_in_sel) + ae1->prev_in_sel->next_in_sel = ae1; + ae1->next_in_sel = ae2; + ae2->prev_in_sel = ae1; + } + + inline bool IsMaxima(const Vertex& v) + { + return ((v.flags & VertexFlags::LocalMax) != VertexFlags::None); + } + + + inline bool IsMaxima(const Active& e) + { + return IsMaxima(*e.vertex_top); + } + + inline Vertex* GetCurrYMaximaVertex_Open(const Active& e) + { + Vertex* result = e.vertex_top; + if (e.wind_dx > 0) + while ((result->next->pt.y == result->pt.y) && + ((result->flags & (VertexFlags::OpenEnd | + VertexFlags::LocalMax)) == VertexFlags::None)) + result = result->next; + else + while (result->prev->pt.y == result->pt.y && + ((result->flags & (VertexFlags::OpenEnd | + VertexFlags::LocalMax)) == VertexFlags::None)) + result = result->prev; + if (!IsMaxima(*result)) result = nullptr; // not a maxima + return result; + } + + inline Vertex* GetCurrYMaximaVertex(const Active& e) + { + Vertex* result = e.vertex_top; + if (e.wind_dx > 0) + while (result->next->pt.y == result->pt.y) result = result->next; + else + while (result->prev->pt.y == result->pt.y) result = result->prev; + if (!IsMaxima(*result)) result = nullptr; // not a maxima + return result; + } + + Active* GetMaximaPair(const Active& e) + { + Active* e2; + e2 = e.next_in_ael; + while (e2) + { + if (e2->vertex_top == e.vertex_top) return e2; // Found! + e2 = e2->next_in_ael; + } + return nullptr; + } + + inline int PointCount(OutPt* op) + { + OutPt* op2 = op; + int cnt = 0; + do + { + op2 = op2->next; + ++cnt; + } while (op2 != op); + return cnt; + } + + inline OutPt* DuplicateOp(OutPt* op, bool insert_after) + { + OutPt* result = new OutPt(op->pt, op->outrec); + if (insert_after) + { + result->next = op->next; + result->next->prev = result; + result->prev = op; + op->next = result; + } + else + { + result->prev = op->prev; + result->prev->next = result; + result->next = op; + op->prev = result; + } + return result; + } + + inline OutPt* DisposeOutPt(OutPt* op) + { + OutPt* result = op->next; + op->prev->next = op->next; + op->next->prev = op->prev; + delete op; + return result; + } + + + inline void DisposeOutPts(OutRec* outrec) + { + OutPt* op = outrec->pts; + op->prev->next = nullptr; + while (op) + { + OutPt* tmp = op; + op = op->next; + delete tmp; + }; + outrec->pts = nullptr; + } + + + bool IntersectListSort(const IntersectNode& a, const IntersectNode& b) + { + //note different inequality tests ... + return (a.pt.y == b.pt.y) ? (a.pt.x < b.pt.x) : (a.pt.y > b.pt.y); + } + + + inline void SetSides(OutRec& outrec, Active& start_edge, Active& end_edge) + { + outrec.front_edge = &start_edge; + outrec.back_edge = &end_edge; + } + + + void SwapOutrecs(Active& e1, Active& e2) + { + OutRec* or1 = e1.outrec; + OutRec* or2 = e2.outrec; + if (or1 == or2) + { + Active* e = or1->front_edge; + or1->front_edge = or1->back_edge; + or1->back_edge = e; + return; + } + if (or1) + { + if (&e1 == or1->front_edge) + or1->front_edge = &e2; + else + or1->back_edge = &e2; + } + if (or2) + { + if (&e2 == or2->front_edge) + or2->front_edge = &e1; + else + or2->back_edge = &e1; + } + e1.outrec = or2; + e2.outrec = or1; + } + + + double Area(OutPt* op) + { + //https://en.wikipedia.org/wiki/Shoelace_formula + double result = 0.0; + OutPt* op2 = op; + do + { + result += static_cast(op2->prev->pt.y + op2->pt.y) * + static_cast(op2->prev->pt.x - op2->pt.x); + op2 = op2->next; + } while (op2 != op); + return result * 0.5; + } + + inline double AreaTriangle(const Point64& pt1, + const Point64& pt2, const Point64& pt3) + { + return (static_cast(pt3.y + pt1.y) * static_cast(pt3.x - pt1.x) + + static_cast(pt1.y + pt2.y) * static_cast(pt1.x - pt2.x) + + static_cast(pt2.y + pt3.y) * static_cast(pt2.x - pt3.x)); + } + + void ReverseOutPts(OutPt* op) + { + if (!op) return; + + OutPt* op1 = op; + OutPt* op2; + + do + { + op2 = op1->next; + op1->next = op1->prev; + op1->prev = op2; + op1 = op2; + } while (op1 != op); + } + + inline void SwapSides(OutRec& outrec) + { + Active* e2 = outrec.front_edge; + outrec.front_edge = outrec.back_edge; + outrec.back_edge = e2; + outrec.pts = outrec.pts->next; + } + + inline OutRec* GetRealOutRec(OutRec* outrec) + { + while (outrec && !outrec->pts) outrec = outrec->owner; + return outrec; + } + + + inline void UncoupleOutRec(Active ae) + { + OutRec* outrec = ae.outrec; + if (!outrec) return; + outrec->front_edge->outrec = nullptr; + outrec->back_edge->outrec = nullptr; + outrec->front_edge = nullptr; + outrec->back_edge = nullptr; + } + + + inline bool PtsReallyClose(const Point64& pt1, const Point64& pt2) + { + return (std::llabs(pt1.x - pt2.x) < 2) && (std::llabs(pt1.y - pt2.y) < 2); + } + + inline bool IsVerySmallTriangle(const OutPt& op) + { + return op.next->next == op.prev && + (PtsReallyClose(op.prev->pt, op.next->pt) || + PtsReallyClose(op.pt, op.next->pt) || + PtsReallyClose(op.pt, op.prev->pt)); + } + + inline bool IsValidClosedPath(const OutPt* op) + { + return op && (op->next != op) && (op->next != op->prev) && + !IsVerySmallTriangle(*op); + } + + inline bool OutrecIsAscending(const Active* hotEdge) + { + return (hotEdge == hotEdge->outrec->front_edge); + } + + inline void SwapFrontBackSides(OutRec& outrec) + { + Active* tmp = outrec.front_edge; + outrec.front_edge = outrec.back_edge; + outrec.back_edge = tmp; + outrec.pts = outrec.pts->next; + } + + inline bool EdgesAdjacentInAEL(const IntersectNode& inode) + { + return (inode.edge1->next_in_ael == inode.edge2) || (inode.edge1->prev_in_ael == inode.edge2); + } + + inline bool IsJoined(const Active& e) + { + return e.join_with != JoinWith::None; + } + + inline void SetOwner(OutRec* outrec, OutRec* new_owner) + { + //precondition1: new_owner is never null + while (new_owner->owner && !new_owner->owner->pts) + new_owner->owner = new_owner->owner->owner; + OutRec* tmp = new_owner; + while (tmp && tmp != outrec) tmp = tmp->owner; + if (tmp) new_owner->owner = outrec->owner; + outrec->owner = new_owner; + } + + //------------------------------------------------------------------------------ + // ClipperBase methods ... + //------------------------------------------------------------------------------ + + ClipperBase::~ClipperBase() + { + Clear(); + } + + void ClipperBase::DeleteEdges(Active*& e) + { + while (e) + { + Active* e2 = e; + e = e->next_in_ael; + delete e2; + } + } + + void ClipperBase::CleanUp() + { + DeleteEdges(actives_); + scanline_list_ = std::priority_queue(); + intersect_nodes_.clear(); + DisposeAllOutRecs(); + horz_seg_list_.clear(); + horz_join_list_.clear(); + } + + + void ClipperBase::Clear() + { + CleanUp(); + DisposeVerticesAndLocalMinima(); + current_locmin_iter_ = minima_list_.begin(); + minima_list_sorted_ = false; + has_open_paths_ = false; + } + + + void ClipperBase::Reset() + { + if (!minima_list_sorted_) + { + std::sort(minima_list_.begin(), minima_list_.end(), LocMinSorter()); + minima_list_sorted_ = true; + } + LocalMinimaList::const_reverse_iterator i; + for (i = minima_list_.rbegin(); i != minima_list_.rend(); ++i) + InsertScanline((*i)->vertex->pt.y); + + current_locmin_iter_ = minima_list_.begin(); + actives_ = nullptr; + sel_ = nullptr; + succeeded_ = true; + } + + +#ifdef USINGZ + void ClipperBase::SetZ(const Active& e1, const Active& e2, Point64& ip) + { + if (!zCallback_) return; + // prioritize subject over clip vertices by passing + // subject vertices before clip vertices in the callback + if (GetPolyType(e1) == PathType::Subject) + { + if (ip == e1.bot) ip.z = e1.bot.z; + else if (ip == e1.top) ip.z = e1.top.z; + else if (ip == e2.bot) ip.z = e2.bot.z; + else if (ip == e2.top) ip.z = e2.top.z; + else ip.z = DefaultZ; + zCallback_(e1.bot, e1.top, e2.bot, e2.top, ip); + } + else + { + if (ip == e2.bot) ip.z = e2.bot.z; + else if (ip == e2.top) ip.z = e2.top.z; + else if (ip == e1.bot) ip.z = e1.bot.z; + else if (ip == e1.top) ip.z = e1.top.z; + else ip.z = DefaultZ; + zCallback_(e2.bot, e2.top, e1.bot, e1.top, ip); + } + } +#endif + + void ClipperBase::AddPath(const Path64& path, PathType polytype, bool is_open) + { + Paths64 tmp; + tmp.push_back(path); + AddPaths(tmp, polytype, is_open); + } + + + void ClipperBase::AddPaths(const Paths64& paths, PathType polytype, bool is_open) + { + if (is_open) has_open_paths_ = true; + minima_list_sorted_ = false; + + const auto total_vertex_count = + std::accumulate(paths.begin(), paths.end(), 0, + [](const auto& a, const Path64& path) + {return a + static_cast(path.size());}); + if (total_vertex_count == 0) return; + + Vertex* vertices = new Vertex[total_vertex_count], * v = vertices; + for (const Path64& path : paths) + { + //for each path create a circular double linked list of vertices + Vertex* v0 = v, * curr_v = v, * prev_v = nullptr; + + if (path.empty()) + continue; + + v->prev = nullptr; + int cnt = 0; + for (const Point64& pt : path) + { + if (prev_v) + { + if (prev_v->pt == pt) continue; // ie skips duplicates + prev_v->next = curr_v; + } + curr_v->prev = prev_v; + curr_v->pt = pt; + curr_v->flags = VertexFlags::None; + prev_v = curr_v++; + cnt++; + } + if (!prev_v || !prev_v->prev) continue; + if (!is_open && prev_v->pt == v0->pt) + prev_v = prev_v->prev; + prev_v->next = v0; + v0->prev = prev_v; + v = curr_v; // ie get ready for next path + if (cnt < 2 || (cnt == 2 && !is_open)) continue; + + //now find and assign local minima + bool going_up, going_up0; + if (is_open) + { + curr_v = v0->next; + while (curr_v != v0 && curr_v->pt.y == v0->pt.y) + curr_v = curr_v->next; + going_up = curr_v->pt.y <= v0->pt.y; + if (going_up) + { + v0->flags = VertexFlags::OpenStart; + AddLocMin(*v0, polytype, true); + } + else + v0->flags = VertexFlags::OpenStart | VertexFlags::LocalMax; + } + else // closed path + { + prev_v = v0->prev; + while (prev_v != v0 && prev_v->pt.y == v0->pt.y) + prev_v = prev_v->prev; + if (prev_v == v0) + continue; // only open paths can be completely flat + going_up = prev_v->pt.y > v0->pt.y; + } + + going_up0 = going_up; + prev_v = v0; + curr_v = v0->next; + while (curr_v != v0) + { + if (curr_v->pt.y > prev_v->pt.y && going_up) + { + prev_v->flags = (prev_v->flags | VertexFlags::LocalMax); + going_up = false; + } + else if (curr_v->pt.y < prev_v->pt.y && !going_up) + { + going_up = true; + AddLocMin(*prev_v, polytype, is_open); + } + prev_v = curr_v; + curr_v = curr_v->next; + } + + if (is_open) + { + prev_v->flags = prev_v->flags | VertexFlags::OpenEnd; + if (going_up) + prev_v->flags = prev_v->flags | VertexFlags::LocalMax; + else + AddLocMin(*prev_v, polytype, is_open); + } + else if (going_up != going_up0) + { + if (going_up0) AddLocMin(*prev_v, polytype, false); + else prev_v->flags = prev_v->flags | VertexFlags::LocalMax; + } + } // end processing current path + + vertex_lists_.emplace_back(vertices); + } // end AddPaths + + + void ClipperBase::InsertScanline(int64_t y) + { + scanline_list_.push(y); + } + + + bool ClipperBase::PopScanline(int64_t& y) + { + if (scanline_list_.empty()) return false; + y = scanline_list_.top(); + scanline_list_.pop(); + while (!scanline_list_.empty() && y == scanline_list_.top()) + scanline_list_.pop(); // Pop duplicates. + return true; + } + + + bool ClipperBase::PopLocalMinima(int64_t y, LocalMinima*& local_minima) + { + if (current_locmin_iter_ == minima_list_.end() || (*current_locmin_iter_)->vertex->pt.y != y) return false; + local_minima = (current_locmin_iter_++)->get(); + return true; + } + + void ClipperBase::DisposeAllOutRecs() + { + for (auto outrec : outrec_list_) + { + if (outrec->pts) DisposeOutPts(outrec); + delete outrec; + } + outrec_list_.resize(0); + } + + void ClipperBase::DisposeVerticesAndLocalMinima() + { + minima_list_.clear(); + for (auto v : vertex_lists_) delete[] v; + vertex_lists_.clear(); + } + + + void ClipperBase::AddLocMin(Vertex& vert, PathType polytype, bool is_open) + { + //make sure the vertex is added only once ... + if ((VertexFlags::LocalMin & vert.flags) != VertexFlags::None) return; + + vert.flags = (vert.flags | VertexFlags::LocalMin); + minima_list_.push_back(std::make_unique (&vert, polytype, is_open)); + } + + bool ClipperBase::IsContributingClosed(const Active& e) const + { + switch (fillrule_) + { + case FillRule::EvenOdd: + break; + case FillRule::NonZero: + if (abs(e.wind_cnt) != 1) return false; + break; + case FillRule::Positive: + if (e.wind_cnt != 1) return false; + break; + case FillRule::Negative: + if (e.wind_cnt != -1) return false; + break; + } + + switch (cliptype_) + { + case ClipType::None: + return false; + case ClipType::Intersection: + switch (fillrule_) + { + case FillRule::Positive: + return (e.wind_cnt2 > 0); + case FillRule::Negative: + return (e.wind_cnt2 < 0); + default: + return (e.wind_cnt2 != 0); + } + break; + + case ClipType::Union: + switch (fillrule_) + { + case FillRule::Positive: + return (e.wind_cnt2 <= 0); + case FillRule::Negative: + return (e.wind_cnt2 >= 0); + default: + return (e.wind_cnt2 == 0); + } + break; + + case ClipType::Difference: + bool result; + switch (fillrule_) + { + case FillRule::Positive: + result = (e.wind_cnt2 <= 0); + break; + case FillRule::Negative: + result = (e.wind_cnt2 >= 0); + break; + default: + result = (e.wind_cnt2 == 0); + } + if (GetPolyType(e) == PathType::Subject) + return result; + else + return !result; + break; + + case ClipType::Xor: return true; break; + } + return false; // we should never get here + } + + + inline bool ClipperBase::IsContributingOpen(const Active& e) const + { + bool is_in_clip, is_in_subj; + switch (fillrule_) + { + case FillRule::Positive: + is_in_clip = e.wind_cnt2 > 0; + is_in_subj = e.wind_cnt > 0; + break; + case FillRule::Negative: + is_in_clip = e.wind_cnt2 < 0; + is_in_subj = e.wind_cnt < 0; + break; + default: + is_in_clip = e.wind_cnt2 != 0; + is_in_subj = e.wind_cnt != 0; + } + + switch (cliptype_) + { + case ClipType::Intersection: return is_in_clip; + case ClipType::Union: return (!is_in_subj && !is_in_clip); + default: return !is_in_clip; + } + } + + + void ClipperBase::SetWindCountForClosedPathEdge(Active& e) + { + //Wind counts refer to polygon regions not edges, so here an edge's WindCnt + //indicates the higher of the wind counts for the two regions touching the + //edge. (NB Adjacent regions can only ever have their wind counts differ by + //one. Also, open paths have no meaningful wind directions or counts.) + + Active* e2 = e.prev_in_ael; + //find the nearest closed path edge of the same PolyType in AEL (heading left) + PathType pt = GetPolyType(e); + while (e2 && (GetPolyType(*e2) != pt || IsOpen(*e2))) e2 = e2->prev_in_ael; + + if (!e2) + { + e.wind_cnt = e.wind_dx; + e2 = actives_; + } + else if (fillrule_ == FillRule::EvenOdd) + { + e.wind_cnt = e.wind_dx; + e.wind_cnt2 = e2->wind_cnt2; + e2 = e2->next_in_ael; + } + else + { + //NonZero, positive, or negative filling here ... + //if e's WindCnt is in the SAME direction as its WindDx, then polygon + //filling will be on the right of 'e'. + //NB neither e2.WindCnt nor e2.WindDx should ever be 0. + if (e2->wind_cnt * e2->wind_dx < 0) + { + //opposite directions so 'e' is outside 'e2' ... + if (abs(e2->wind_cnt) > 1) + { + //outside prev poly but still inside another. + if (e2->wind_dx * e.wind_dx < 0) + //reversing direction so use the same WC + e.wind_cnt = e2->wind_cnt; + else + //otherwise keep 'reducing' the WC by 1 (ie towards 0) ... + e.wind_cnt = e2->wind_cnt + e.wind_dx; + } + else + //now outside all polys of same polytype so set own WC ... + e.wind_cnt = (IsOpen(e) ? 1 : e.wind_dx); + } + else + { + //'e' must be inside 'e2' + if (e2->wind_dx * e.wind_dx < 0) + //reversing direction so use the same WC + e.wind_cnt = e2->wind_cnt; + else + //otherwise keep 'increasing' the WC by 1 (ie away from 0) ... + e.wind_cnt = e2->wind_cnt + e.wind_dx; + } + e.wind_cnt2 = e2->wind_cnt2; + e2 = e2->next_in_ael; // ie get ready to calc WindCnt2 + } + + //update wind_cnt2 ... + if (fillrule_ == FillRule::EvenOdd) + while (e2 != &e) + { + if (GetPolyType(*e2) != pt && !IsOpen(*e2)) + e.wind_cnt2 = (e.wind_cnt2 == 0 ? 1 : 0); + e2 = e2->next_in_ael; + } + else + while (e2 != &e) + { + if (GetPolyType(*e2) != pt && !IsOpen(*e2)) + e.wind_cnt2 += e2->wind_dx; + e2 = e2->next_in_ael; + } + } + + + void ClipperBase::SetWindCountForOpenPathEdge(Active& e) + { + Active* e2 = actives_; + if (fillrule_ == FillRule::EvenOdd) + { + int cnt1 = 0, cnt2 = 0; + while (e2 != &e) + { + if (GetPolyType(*e2) == PathType::Clip) + cnt2++; + else if (!IsOpen(*e2)) + cnt1++; + e2 = e2->next_in_ael; + } + e.wind_cnt = (IsOdd(cnt1) ? 1 : 0); + e.wind_cnt2 = (IsOdd(cnt2) ? 1 : 0); + } + else + { + while (e2 != &e) + { + if (GetPolyType(*e2) == PathType::Clip) + e.wind_cnt2 += e2->wind_dx; + else if (!IsOpen(*e2)) + e.wind_cnt += e2->wind_dx; + e2 = e2->next_in_ael; + } + } + } + + + bool IsValidAelOrder(const Active& resident, const Active& newcomer) + { + if (newcomer.curr_x != resident.curr_x) + return newcomer.curr_x > resident.curr_x; + + //get the turning direction a1.top, a2.bot, a2.top + double d = CrossProduct(resident.top, newcomer.bot, newcomer.top); + if (d != 0) return d < 0; + + //edges must be collinear to get here + //for starting open paths, place them according to + //the direction they're about to turn + if (!IsMaxima(resident) && (resident.top.y > newcomer.top.y)) + { + return CrossProduct(newcomer.bot, + resident.top, NextVertex(resident)->pt) <= 0; + } + else if (!IsMaxima(newcomer) && (newcomer.top.y > resident.top.y)) + { + return CrossProduct(newcomer.bot, + newcomer.top, NextVertex(newcomer)->pt) >= 0; + } + + int64_t y = newcomer.bot.y; + bool newcomerIsLeft = newcomer.is_left_bound; + + if (resident.bot.y != y || resident.local_min->vertex->pt.y != y) + return newcomer.is_left_bound; + //resident must also have just been inserted + else if (resident.is_left_bound != newcomerIsLeft) + return newcomerIsLeft; + else if (CrossProduct(PrevPrevVertex(resident)->pt, + resident.bot, resident.top) == 0) return true; + else + //compare turning direction of the alternate bound + return (CrossProduct(PrevPrevVertex(resident)->pt, + newcomer.bot, PrevPrevVertex(newcomer)->pt) > 0) == newcomerIsLeft; + } + + + void ClipperBase::InsertLeftEdge(Active& e) + { + Active* e2; + if (!actives_) + { + e.prev_in_ael = nullptr; + e.next_in_ael = nullptr; + actives_ = &e; + } + else if (!IsValidAelOrder(*actives_, e)) + { + e.prev_in_ael = nullptr; + e.next_in_ael = actives_; + actives_->prev_in_ael = &e; + actives_ = &e; + } + else + { + e2 = actives_; + while (e2->next_in_ael && IsValidAelOrder(*e2->next_in_ael, e)) + e2 = e2->next_in_ael; + if (e2->join_with == JoinWith::Right) + e2 = e2->next_in_ael; + if (!e2) return; // should never happen and stops compiler warning :) + e.next_in_ael = e2->next_in_ael; + if (e2->next_in_ael) e2->next_in_ael->prev_in_ael = &e; + e.prev_in_ael = e2; + e2->next_in_ael = &e; + } + } + + + void InsertRightEdge(Active& e, Active& e2) + { + e2.next_in_ael = e.next_in_ael; + if (e.next_in_ael) e.next_in_ael->prev_in_ael = &e2; + e2.prev_in_ael = &e; + e.next_in_ael = &e2; + } + + + void ClipperBase::InsertLocalMinimaIntoAEL(int64_t bot_y) + { + LocalMinima* local_minima; + Active* left_bound, * right_bound; + //Add any local minima (if any) at BotY ... + //nb: horizontal local minima edges should contain locMin.vertex.prev + + while (PopLocalMinima(bot_y, local_minima)) + { + if ((local_minima->vertex->flags & VertexFlags::OpenStart) != VertexFlags::None) + { + left_bound = nullptr; + } + else + { + left_bound = new Active(); + left_bound->bot = local_minima->vertex->pt; + left_bound->curr_x = left_bound->bot.x; + left_bound->wind_dx = -1; + left_bound->vertex_top = local_minima->vertex->prev; // ie descending + left_bound->top = left_bound->vertex_top->pt; + left_bound->local_min = local_minima; + SetDx(*left_bound); + } + + if ((local_minima->vertex->flags & VertexFlags::OpenEnd) != VertexFlags::None) + { + right_bound = nullptr; + } + else + { + right_bound = new Active(); + right_bound->bot = local_minima->vertex->pt; + right_bound->curr_x = right_bound->bot.x; + right_bound->wind_dx = 1; + right_bound->vertex_top = local_minima->vertex->next; // ie ascending + right_bound->top = right_bound->vertex_top->pt; + right_bound->local_min = local_minima; + SetDx(*right_bound); + } + + //Currently LeftB is just the descending bound and RightB is the ascending. + //Now if the LeftB isn't on the left of RightB then we need swap them. + if (left_bound && right_bound) + { + if (IsHorizontal(*left_bound)) + { + if (IsHeadingRightHorz(*left_bound)) SwapActives(left_bound, right_bound); + } + else if (IsHorizontal(*right_bound)) + { + if (IsHeadingLeftHorz(*right_bound)) SwapActives(left_bound, right_bound); + } + else if (left_bound->dx < right_bound->dx) + SwapActives(left_bound, right_bound); + } + else if (!left_bound) + { + left_bound = right_bound; + right_bound = nullptr; + } + + bool contributing; + left_bound->is_left_bound = true; + InsertLeftEdge(*left_bound); + + if (IsOpen(*left_bound)) + { + SetWindCountForOpenPathEdge(*left_bound); + contributing = IsContributingOpen(*left_bound); + } + else + { + SetWindCountForClosedPathEdge(*left_bound); + contributing = IsContributingClosed(*left_bound); + } + + if (right_bound) + { + right_bound->is_left_bound = false; + right_bound->wind_cnt = left_bound->wind_cnt; + right_bound->wind_cnt2 = left_bound->wind_cnt2; + InsertRightEdge(*left_bound, *right_bound); /////// + if (contributing) + { + AddLocalMinPoly(*left_bound, *right_bound, left_bound->bot, true); + if (!IsHorizontal(*left_bound)) + CheckJoinLeft(*left_bound, left_bound->bot); + } + + while (right_bound->next_in_ael && + IsValidAelOrder(*right_bound->next_in_ael, *right_bound)) + { + IntersectEdges(*right_bound, *right_bound->next_in_ael, right_bound->bot); + SwapPositionsInAEL(*right_bound, *right_bound->next_in_ael); + } + + if (IsHorizontal(*right_bound)) + PushHorz(*right_bound); + else + { + CheckJoinRight(*right_bound, right_bound->bot); + InsertScanline(right_bound->top.y); + } + } + else if (contributing) + { + StartOpenPath(*left_bound, left_bound->bot); + } + + if (IsHorizontal(*left_bound)) + PushHorz(*left_bound); + else + InsertScanline(left_bound->top.y); + } // while (PopLocalMinima()) + } + + + inline void ClipperBase::PushHorz(Active& e) + { + e.next_in_sel = (sel_ ? sel_ : nullptr); + sel_ = &e; + } + + + inline bool ClipperBase::PopHorz(Active*& e) + { + e = sel_; + if (!e) return false; + sel_ = sel_->next_in_sel; + return true; + } + + + OutPt* ClipperBase::AddLocalMinPoly(Active& e1, Active& e2, + const Point64& pt, bool is_new) + { + OutRec* outrec = NewOutRec(); + e1.outrec = outrec; + e2.outrec = outrec; + + if (IsOpen(e1)) + { + outrec->owner = nullptr; + outrec->is_open = true; + if (e1.wind_dx > 0) + SetSides(*outrec, e1, e2); + else + SetSides(*outrec, e2, e1); + } + else + { + Active* prevHotEdge = GetPrevHotEdge(e1); + //e.windDx is the winding direction of the **input** paths + //and unrelated to the winding direction of output polygons. + //Output orientation is determined by e.outrec.frontE which is + //the ascending edge (see AddLocalMinPoly). + if (prevHotEdge) + { + if (using_polytree_) + SetOwner(outrec, prevHotEdge->outrec); + if (OutrecIsAscending(prevHotEdge) == is_new) + SetSides(*outrec, e2, e1); + else + SetSides(*outrec, e1, e2); + } + else + { + outrec->owner = nullptr; + if (is_new) + SetSides(*outrec, e1, e2); + else + SetSides(*outrec, e2, e1); + } + } + + OutPt* op = new OutPt(pt, outrec); + outrec->pts = op; + return op; + } + + + OutPt* ClipperBase::AddLocalMaxPoly(Active& e1, Active& e2, const Point64& pt) + { + if (IsJoined(e1)) Split(e1, pt); + if (IsJoined(e2)) Split(e2, pt); + + if (IsFront(e1) == IsFront(e2)) + { + if (IsOpenEnd(e1)) + SwapFrontBackSides(*e1.outrec); + else if (IsOpenEnd(e2)) + SwapFrontBackSides(*e2.outrec); + else + { + succeeded_ = false; + return nullptr; + } + } + + OutPt* result = AddOutPt(e1, pt); + if (e1.outrec == e2.outrec) + { + OutRec& outrec = *e1.outrec; + outrec.pts = result; + + if (using_polytree_) + { + Active* e = GetPrevHotEdge(e1); + if (!e) + outrec.owner = nullptr; + else + SetOwner(&outrec, e->outrec); + // nb: outRec.owner here is likely NOT the real + // owner but this will be checked in DeepCheckOwner() + } + + UncoupleOutRec(e1); + result = outrec.pts; + if (outrec.owner && !outrec.owner->front_edge) + outrec.owner = GetRealOutRec(outrec.owner); + } + //and to preserve the winding orientation of outrec ... + else if (IsOpen(e1)) + { + if (e1.wind_dx < 0) + JoinOutrecPaths(e1, e2); + else + JoinOutrecPaths(e2, e1); + } + else if (e1.outrec->idx < e2.outrec->idx) + JoinOutrecPaths(e1, e2); + else + JoinOutrecPaths(e2, e1); + return result; + } + + void ClipperBase::JoinOutrecPaths(Active& e1, Active& e2) + { + //join e2 outrec path onto e1 outrec path and then delete e2 outrec path + //pointers. (NB Only very rarely do the joining ends share the same coords.) + OutPt* p1_st = e1.outrec->pts; + OutPt* p2_st = e2.outrec->pts; + OutPt* p1_end = p1_st->next; + OutPt* p2_end = p2_st->next; + if (IsFront(e1)) + { + p2_end->prev = p1_st; + p1_st->next = p2_end; + p2_st->next = p1_end; + p1_end->prev = p2_st; + e1.outrec->pts = p2_st; + e1.outrec->front_edge = e2.outrec->front_edge; + if (e1.outrec->front_edge) + e1.outrec->front_edge->outrec = e1.outrec; + } + else + { + p1_end->prev = p2_st; + p2_st->next = p1_end; + p1_st->next = p2_end; + p2_end->prev = p1_st; + e1.outrec->back_edge = e2.outrec->back_edge; + if (e1.outrec->back_edge) + e1.outrec->back_edge->outrec = e1.outrec; + } + + //after joining, the e2.OutRec must contains no vertices ... + e2.outrec->front_edge = nullptr; + e2.outrec->back_edge = nullptr; + e2.outrec->pts = nullptr; + SetOwner(e2.outrec, e1.outrec); + + if (IsOpenEnd(e1)) + { + e2.outrec->pts = e1.outrec->pts; + e1.outrec->pts = nullptr; + } + + //and e1 and e2 are maxima and are about to be dropped from the Actives list. + e1.outrec = nullptr; + e2.outrec = nullptr; + } + + OutRec* ClipperBase::NewOutRec() + { + OutRec* result = new OutRec(); + result->idx = outrec_list_.size(); + outrec_list_.push_back(result); + result->pts = nullptr; + result->owner = nullptr; + result->polypath = nullptr; + result->is_open = false; + return result; + } + + + OutPt* ClipperBase::AddOutPt(const Active& e, const Point64& pt) + { + OutPt* new_op = nullptr; + + //Outrec.OutPts: a circular doubly-linked-list of POutPt where ... + //op_front[.Prev]* ~~~> op_back & op_back == op_front.Next + OutRec* outrec = e.outrec; + bool to_front = IsFront(e); + OutPt* op_front = outrec->pts; + OutPt* op_back = op_front->next; + + if (to_front) + { + if (pt == op_front->pt) + return op_front; + } + else if (pt == op_back->pt) + return op_back; + + new_op = new OutPt(pt, outrec); + op_back->prev = new_op; + new_op->prev = op_front; + new_op->next = op_back; + op_front->next = new_op; + if (to_front) outrec->pts = new_op; + return new_op; + } + + + void ClipperBase::CleanCollinear(OutRec* outrec) + { + outrec = GetRealOutRec(outrec); + if (!outrec || outrec->is_open) return; + if (!IsValidClosedPath(outrec->pts)) + { + DisposeOutPts(outrec); + return; + } + + OutPt* startOp = outrec->pts, * op2 = startOp; + for (; ; ) + { + //NB if preserveCollinear == true, then only remove 180 deg. spikes + if ((CrossProduct(op2->prev->pt, op2->pt, op2->next->pt) == 0) && + (op2->pt == op2->prev->pt || + op2->pt == op2->next->pt || !PreserveCollinear || + DotProduct(op2->prev->pt, op2->pt, op2->next->pt) < 0)) + { + + if (op2 == outrec->pts) outrec->pts = op2->prev; + + op2 = DisposeOutPt(op2); + if (!IsValidClosedPath(op2)) + { + DisposeOutPts(outrec); + return; + } + startOp = op2; + continue; + } + op2 = op2->next; + if (op2 == startOp) break; + } + FixSelfIntersects(outrec); + } + + void ClipperBase::DoSplitOp(OutRec* outrec, OutPt* splitOp) + { + // splitOp.prev -> splitOp && + // splitOp.next -> splitOp.next.next are intersecting + OutPt* prevOp = splitOp->prev; + OutPt* nextNextOp = splitOp->next->next; + outrec->pts = prevOp; + + Point64 ip; + GetIntersectPoint(prevOp->pt, splitOp->pt, + splitOp->next->pt, nextNextOp->pt, ip); + +#ifdef USINGZ + if (zCallback_) zCallback_(prevOp->pt, splitOp->pt, + splitOp->next->pt, nextNextOp->pt, ip); +#endif + double area1 = Area(outrec->pts); + double absArea1 = std::fabs(area1); + if (absArea1 < 2) + { + DisposeOutPts(outrec); + return; + } + + // nb: area1 is the path's area *before* splitting, whereas area2 is + // the area of the triangle containing splitOp & splitOp.next. + // So the only way for these areas to have the same sign is if + // the split triangle is larger than the path containing prevOp or + // if there's more than one self=intersection. + double area2 = AreaTriangle(ip, splitOp->pt, splitOp->next->pt); + double absArea2 = std::fabs(area2); + + // de-link splitOp and splitOp.next from the path + // while inserting the intersection point + if (ip == prevOp->pt || ip == nextNextOp->pt) + { + nextNextOp->prev = prevOp; + prevOp->next = nextNextOp; + } + else + { + OutPt* newOp2 = new OutPt(ip, prevOp->outrec); + newOp2->prev = prevOp; + newOp2->next = nextNextOp; + nextNextOp->prev = newOp2; + prevOp->next = newOp2; + } + + if (absArea2 >= 1 && + (absArea2 > absArea1 || (area2 > 0) == (area1 > 0))) + { + OutRec* newOr = NewOutRec(); + newOr->owner = outrec->owner; + + if (using_polytree_) + { + if (!outrec->splits) outrec->splits = new OutRecList(); + outrec->splits->push_back(newOr); + } + + splitOp->outrec = newOr; + splitOp->next->outrec = newOr; + OutPt* newOp = new OutPt(ip, newOr); + newOp->prev = splitOp->next; + newOp->next = splitOp; + newOr->pts = newOp; + splitOp->prev = newOp; + splitOp->next->next = newOp; + } + else + { + delete splitOp->next; + delete splitOp; + } + } + + void ClipperBase::FixSelfIntersects(OutRec* outrec) + { + OutPt* op2 = outrec->pts; + for (; ; ) + { + // triangles can't self-intersect + if (op2->prev == op2->next->next) break; + if (SegmentsIntersect(op2->prev->pt, + op2->pt, op2->next->pt, op2->next->next->pt)) + { + if (op2 == outrec->pts || op2->next == outrec->pts) + outrec->pts = outrec->pts->prev; + DoSplitOp(outrec, op2); + if (!outrec->pts) break; + op2 = outrec->pts; + continue; + } + else + op2 = op2->next; + + if (op2 == outrec->pts) break; + } + } + + + inline void UpdateOutrecOwner(OutRec* outrec) + { + OutPt* opCurr = outrec->pts; + for (; ; ) + { + opCurr->outrec = outrec; + opCurr = opCurr->next; + if (opCurr == outrec->pts) return; + } + } + + + OutPt* ClipperBase::StartOpenPath(Active& e, const Point64& pt) + { + OutRec* outrec = NewOutRec(); + outrec->is_open = true; + + if (e.wind_dx > 0) + { + outrec->front_edge = &e; + outrec->back_edge = nullptr; + } + else + { + outrec->front_edge = nullptr; + outrec->back_edge = &e; + } + + e.outrec = outrec; + + OutPt* op = new OutPt(pt, outrec); + outrec->pts = op; + return op; + } + + + inline void ClipperBase::UpdateEdgeIntoAEL(Active* e) + { + e->bot = e->top; + e->vertex_top = NextVertex(*e); + e->top = e->vertex_top->pt; + e->curr_x = e->bot.x; + SetDx(*e); + + if (IsJoined(*e)) Split(*e, e->bot); + + if (IsHorizontal(*e)) return; + InsertScanline(e->top.y); + + CheckJoinLeft(*e, e->bot); + CheckJoinRight(*e, e->bot); + } + + Active* FindEdgeWithMatchingLocMin(Active* e) + { + Active* result = e->next_in_ael; + while (result) + { + if (result->local_min == e->local_min) return result; + else if (!IsHorizontal(*result) && e->bot != result->bot) result = nullptr; + else result = result->next_in_ael; + } + result = e->prev_in_ael; + while (result) + { + if (result->local_min == e->local_min) return result; + else if (!IsHorizontal(*result) && e->bot != result->bot) return nullptr; + else result = result->prev_in_ael; + } + return result; + } + + + OutPt* ClipperBase::IntersectEdges(Active& e1, Active& e2, const Point64& pt) + { + //MANAGE OPEN PATH INTERSECTIONS SEPARATELY ... + if (has_open_paths_ && (IsOpen(e1) || IsOpen(e2))) + { + if (IsOpen(e1) && IsOpen(e2)) return nullptr; + Active* edge_o, * edge_c; + if (IsOpen(e1)) + { + edge_o = &e1; + edge_c = &e2; + } + else + { + edge_o = &e2; + edge_c = &e1; + } + if (IsJoined(*edge_c)) Split(*edge_c, pt); // needed for safety + + if (abs(edge_c->wind_cnt) != 1) return nullptr; + switch (cliptype_) + { + case ClipType::Union: + if (!IsHotEdge(*edge_c)) return nullptr; + break; + default: + if (edge_c->local_min->polytype == PathType::Subject) + return nullptr; + } + + switch (fillrule_) + { + case FillRule::Positive: if (edge_c->wind_cnt != 1) return nullptr; break; + case FillRule::Negative: if (edge_c->wind_cnt != -1) return nullptr; break; + default: if (std::abs(edge_c->wind_cnt) != 1) return nullptr; break; + } + + //toggle contribution ... + if (IsHotEdge(*edge_o)) + { + OutPt* resultOp = AddOutPt(*edge_o, pt); +#ifdef USINGZ + if (zCallback_) SetZ(e1, e2, resultOp->pt); +#endif + if (IsFront(*edge_o)) edge_o->outrec->front_edge = nullptr; + else edge_o->outrec->back_edge = nullptr; + edge_o->outrec = nullptr; + return resultOp; + } + + //horizontal edges can pass under open paths at a LocMins + else if (pt == edge_o->local_min->vertex->pt && + !IsOpenEnd(*edge_o->local_min->vertex)) + { + //find the other side of the LocMin and + //if it's 'hot' join up with it ... + Active* e3 = FindEdgeWithMatchingLocMin(edge_o); + if (e3 && IsHotEdge(*e3)) + { + edge_o->outrec = e3->outrec; + if (edge_o->wind_dx > 0) + SetSides(*e3->outrec, *edge_o, *e3); + else + SetSides(*e3->outrec, *e3, *edge_o); + return e3->outrec->pts; + } + else + return StartOpenPath(*edge_o, pt); + } + else + return StartOpenPath(*edge_o, pt); + } + + //MANAGING CLOSED PATHS FROM HERE ON + + if (IsJoined(e1)) Split(e1, pt); + if (IsJoined(e2)) Split(e2, pt); + + //UPDATE WINDING COUNTS... + + int old_e1_windcnt, old_e2_windcnt; + if (e1.local_min->polytype == e2.local_min->polytype) + { + if (fillrule_ == FillRule::EvenOdd) + { + old_e1_windcnt = e1.wind_cnt; + e1.wind_cnt = e2.wind_cnt; + e2.wind_cnt = old_e1_windcnt; + } + else + { + if (e1.wind_cnt + e2.wind_dx == 0) + e1.wind_cnt = -e1.wind_cnt; + else + e1.wind_cnt += e2.wind_dx; + if (e2.wind_cnt - e1.wind_dx == 0) + e2.wind_cnt = -e2.wind_cnt; + else + e2.wind_cnt -= e1.wind_dx; + } + } + else + { + if (fillrule_ != FillRule::EvenOdd) + { + e1.wind_cnt2 += e2.wind_dx; + e2.wind_cnt2 -= e1.wind_dx; + } + else + { + e1.wind_cnt2 = (e1.wind_cnt2 == 0 ? 1 : 0); + e2.wind_cnt2 = (e2.wind_cnt2 == 0 ? 1 : 0); + } + } + + switch (fillrule_) + { + case FillRule::EvenOdd: + case FillRule::NonZero: + old_e1_windcnt = abs(e1.wind_cnt); + old_e2_windcnt = abs(e2.wind_cnt); + break; + default: + if (fillrule_ == fillpos) + { + old_e1_windcnt = e1.wind_cnt; + old_e2_windcnt = e2.wind_cnt; + } + else + { + old_e1_windcnt = -e1.wind_cnt; + old_e2_windcnt = -e2.wind_cnt; + } + break; + } + + const bool e1_windcnt_in_01 = old_e1_windcnt == 0 || old_e1_windcnt == 1; + const bool e2_windcnt_in_01 = old_e2_windcnt == 0 || old_e2_windcnt == 1; + + if ((!IsHotEdge(e1) && !e1_windcnt_in_01) || (!IsHotEdge(e2) && !e2_windcnt_in_01)) + { + return nullptr; + } + + //NOW PROCESS THE INTERSECTION ... + OutPt* resultOp = nullptr; + //if both edges are 'hot' ... + if (IsHotEdge(e1) && IsHotEdge(e2)) + { + if ((old_e1_windcnt != 0 && old_e1_windcnt != 1) || (old_e2_windcnt != 0 && old_e2_windcnt != 1) || + (e1.local_min->polytype != e2.local_min->polytype && cliptype_ != ClipType::Xor)) + { + resultOp = AddLocalMaxPoly(e1, e2, pt); +#ifdef USINGZ + if (zCallback_ && resultOp) SetZ(e1, e2, resultOp->pt); +#endif + } + else if (IsFront(e1) || (e1.outrec == e2.outrec)) + { + //this 'else if' condition isn't strictly needed but + //it's sensible to split polygons that ony touch at + //a common vertex (not at common edges). + + resultOp = AddLocalMaxPoly(e1, e2, pt); +#ifdef USINGZ + OutPt* op2 = AddLocalMinPoly(e1, e2, pt); + if (zCallback_ && resultOp) SetZ(e1, e2, resultOp->pt); + if (zCallback_) SetZ(e1, e2, op2->pt); +#else + AddLocalMinPoly(e1, e2, pt); +#endif + } + else + { + resultOp = AddOutPt(e1, pt); +#ifdef USINGZ + OutPt* op2 = AddOutPt(e2, pt); + if (zCallback_) + { + SetZ(e1, e2, resultOp->pt); + SetZ(e1, e2, op2->pt); + } +#else + AddOutPt(e2, pt); +#endif + SwapOutrecs(e1, e2); + } + } + else if (IsHotEdge(e1)) + { + resultOp = AddOutPt(e1, pt); +#ifdef USINGZ + if (zCallback_) SetZ(e1, e2, resultOp->pt); +#endif + SwapOutrecs(e1, e2); + } + else if (IsHotEdge(e2)) + { + resultOp = AddOutPt(e2, pt); +#ifdef USINGZ + if (zCallback_) SetZ(e1, e2, resultOp->pt); +#endif + SwapOutrecs(e1, e2); + } + else + { + int64_t e1Wc2, e2Wc2; + switch (fillrule_) + { + case FillRule::EvenOdd: + case FillRule::NonZero: + e1Wc2 = abs(e1.wind_cnt2); + e2Wc2 = abs(e2.wind_cnt2); + break; + default: + if (fillrule_ == fillpos) + { + e1Wc2 = e1.wind_cnt2; + e2Wc2 = e2.wind_cnt2; + } + else + { + e1Wc2 = -e1.wind_cnt2; + e2Wc2 = -e2.wind_cnt2; + } + break; + } + + if (!IsSamePolyType(e1, e2)) + { + resultOp = AddLocalMinPoly(e1, e2, pt, false); +#ifdef USINGZ + if (zCallback_) SetZ(e1, e2, resultOp->pt); +#endif + } + else if (old_e1_windcnt == 1 && old_e2_windcnt == 1) + { + resultOp = nullptr; + switch (cliptype_) + { + case ClipType::Union: + if (e1Wc2 <= 0 && e2Wc2 <= 0) + resultOp = AddLocalMinPoly(e1, e2, pt, false); + break; + case ClipType::Difference: + if (((GetPolyType(e1) == PathType::Clip) && (e1Wc2 > 0) && (e2Wc2 > 0)) || + ((GetPolyType(e1) == PathType::Subject) && (e1Wc2 <= 0) && (e2Wc2 <= 0))) + { + resultOp = AddLocalMinPoly(e1, e2, pt, false); + } + break; + case ClipType::Xor: + resultOp = AddLocalMinPoly(e1, e2, pt, false); + break; + default: + if (e1Wc2 > 0 && e2Wc2 > 0) + resultOp = AddLocalMinPoly(e1, e2, pt, false); + break; + } +#ifdef USINGZ + if (resultOp && zCallback_) SetZ(e1, e2, resultOp->pt); +#endif + } + } + return resultOp; + } + + inline void ClipperBase::DeleteFromAEL(Active& e) + { + Active* prev = e.prev_in_ael; + Active* next = e.next_in_ael; + if (!prev && !next && (&e != actives_)) return; // already deleted + if (prev) + prev->next_in_ael = next; + else + actives_ = next; + if (next) next->prev_in_ael = prev; + delete& e; + } + + + inline void ClipperBase::AdjustCurrXAndCopyToSEL(const int64_t top_y) + { + Active* e = actives_; + sel_ = e; + while (e) + { + e->prev_in_sel = e->prev_in_ael; + e->next_in_sel = e->next_in_ael; + e->jump = e->next_in_sel; + if (e->join_with == JoinWith::Left) + e->curr_x = e->prev_in_ael->curr_x; // also avoids complications + else + e->curr_x = TopX(*e, top_y); + e = e->next_in_ael; + } + } + + bool ClipperBase::ExecuteInternal(ClipType ct, FillRule fillrule, bool use_polytrees) + { + cliptype_ = ct; + fillrule_ = fillrule; + using_polytree_ = use_polytrees; + Reset(); + int64_t y; + if (ct == ClipType::None || !PopScanline(y)) return true; + + while (succeeded_) + { + InsertLocalMinimaIntoAEL(y); + Active* e; + while (PopHorz(e)) DoHorizontal(*e); + if (horz_seg_list_.size() > 0) + { + ConvertHorzSegsToJoins(); + horz_seg_list_.clear(); + } + bot_y_ = y; // bot_y_ == bottom of scanbeam + if (!PopScanline(y)) break; // y new top of scanbeam + DoIntersections(y); + DoTopOfScanbeam(y); + while (PopHorz(e)) DoHorizontal(*e); + } + if (succeeded_) ProcessHorzJoins(); + return succeeded_; + } + + inline void FixOutRecPts(OutRec* outrec) + { + OutPt* op = outrec->pts; + do { + op->outrec = outrec; + op = op->next; + } while (op != outrec->pts); + } + + inline Rect64 GetBounds(OutPt* op) + { + Rect64 result(op->pt.x, op->pt.y, op->pt.x, op->pt.y); + OutPt* op2 = op->next; + while (op2 != op) + { + if (op2->pt.x < result.left) result.left = op2->pt.x; + else if (op2->pt.x > result.right) result.right = op2->pt.x; + if (op2->pt.y < result.top) result.top = op2->pt.y; + else if (op2->pt.y > result.bottom) result.bottom = op2->pt.y; + op2 = op2->next; + } + return result; + } + + static PointInPolygonResult PointInOpPolygon(const Point64& pt, OutPt* op) + { + if (op == op->next || op->prev == op->next) + return PointInPolygonResult::IsOutside; + + OutPt* op2 = op; + do + { + if (op->pt.y != pt.y) break; + op = op->next; + } while (op != op2); + if (op->pt.y == pt.y) // not a proper polygon + return PointInPolygonResult::IsOutside; + + bool is_above = op->pt.y < pt.y, starting_above = is_above; + int val = 0; + op2 = op->next; + while (op2 != op) + { + if (is_above) + while (op2 != op && op2->pt.y < pt.y) op2 = op2->next; + else + while (op2 != op && op2->pt.y > pt.y) op2 = op2->next; + if (op2 == op) break; + + // must have touched or crossed the pt.Y horizonal + // and this must happen an even number of times + + if (op2->pt.y == pt.y) // touching the horizontal + { + if (op2->pt.x == pt.x || (op2->pt.y == op2->prev->pt.y && + (pt.x < op2->prev->pt.x) != (pt.x < op2->pt.x))) + return PointInPolygonResult::IsOn; + + op2 = op2->next; + if (op2 == op) break; + continue; + } + + if (pt.x < op2->pt.x && pt.x < op2->prev->pt.x); + // do nothing because + // we're only interested in edges crossing on the left + else if ((pt.x > op2->prev->pt.x && pt.x > op2->pt.x)) + val = 1 - val; // toggle val + else + { + double d = CrossProduct(op2->prev->pt, op2->pt, pt); + if (d == 0) return PointInPolygonResult::IsOn; + if ((d < 0) == is_above) val = 1 - val; + } + is_above = !is_above; + op2 = op2->next; + } + + if (is_above != starting_above) + { + double d = CrossProduct(op2->prev->pt, op2->pt, pt); + if (d == 0) return PointInPolygonResult::IsOn; + if ((d < 0) == is_above) val = 1 - val; + } + + if (val == 0) return PointInPolygonResult::IsOutside; + else return PointInPolygonResult::IsInside; + } + + inline bool Path1InsidePath2(OutPt* op1, OutPt* op2) + { + // we need to make some accommodation for rounding errors + // so we won't jump if the first vertex is found outside + int outside_cnt = 0; + OutPt* op = op1; + do + { + PointInPolygonResult result = PointInOpPolygon(op->pt, op2); + if (result == PointInPolygonResult::IsOutside) ++outside_cnt; + else if (result == PointInPolygonResult::IsInside) --outside_cnt; + op = op->next; + } while (op != op1 && std::abs(outside_cnt) < 2); + if (std::abs(outside_cnt) > 1) return (outside_cnt < 0); + // since path1's location is still equivocal, check its midpoint + Point64 mp = GetBounds(op).MidPoint(); + return PointInOpPolygon(mp, op2) == PointInPolygonResult::IsInside; + } + + inline bool SetHorzSegHeadingForward(HorzSegment& hs, OutPt* opP, OutPt* opN) + { + if (opP->pt.x == opN->pt.x) return false; + if (opP->pt.x < opN->pt.x) + { + hs.left_op = opP; + hs.right_op = opN; + hs.left_to_right = true; + } + else + { + hs.left_op = opN; + hs.right_op = opP; + hs.left_to_right = false; + } + return true; + } + + inline bool UpdateHorzSegment(HorzSegment& hs) + { + OutPt* op = hs.left_op; + OutRec* outrec = GetRealOutRec(op->outrec); + bool outrecHasEdges = outrec->front_edge; + int64_t curr_y = op->pt.y; + OutPt* opP = op, * opN = op; + if (outrecHasEdges) + { + OutPt* opA = outrec->pts, * opZ = opA->next; + while (opP != opZ && opP->prev->pt.y == curr_y) + opP = opP->prev; + while (opN != opA && opN->next->pt.y == curr_y) + opN = opN->next; + } + else + { + while (opP->prev != opN && opP->prev->pt.y == curr_y) + opP = opP->prev; + while (opN->next != opP && opN->next->pt.y == curr_y) + opN = opN->next; + } + bool result = + SetHorzSegHeadingForward(hs, opP, opN) && + !hs.left_op->horz; + + if (result) + hs.left_op->horz = &hs; + else + hs.right_op = nullptr; // (for sorting) + return result; + } + + void ClipperBase::ConvertHorzSegsToJoins() + { + auto j = std::count_if(horz_seg_list_.begin(), + horz_seg_list_.end(), + [](HorzSegment& hs) { return UpdateHorzSegment(hs); }); + if (j < 2) return; + std::sort(horz_seg_list_.begin(), horz_seg_list_.end(), HorzSegSorter()); + + HorzSegmentList::iterator hs1 = horz_seg_list_.begin(), hs2; + HorzSegmentList::iterator hs_end = hs1 +j; + HorzSegmentList::iterator hs_end1 = hs_end - 1; + + for (; hs1 != hs_end1; ++hs1) + { + for (hs2 = hs1 + 1; hs2 != hs_end; ++hs2) + { + if (hs2->left_op->pt.x >= hs1->right_op->pt.x) break; + if (hs2->left_to_right == hs1->left_to_right || + (hs2->right_op->pt.x <= hs1->left_op->pt.x)) continue; + int64_t curr_y = hs1->left_op->pt.y; + if (hs1->left_to_right) + { + while (hs1->left_op->next->pt.y == curr_y && + hs1->left_op->next->pt.x <= hs2->left_op->pt.x) + hs1->left_op = hs1->left_op->next; + while (hs2->left_op->prev->pt.y == curr_y && + hs2->left_op->prev->pt.x <= hs1->left_op->pt.x) + hs2->left_op = hs2->left_op->prev; + HorzJoin join = HorzJoin( + DuplicateOp(hs1->left_op, true), + DuplicateOp(hs2->left_op, false)); + horz_join_list_.push_back(join); + } + else + { + while (hs1->left_op->prev->pt.y == curr_y && + hs1->left_op->prev->pt.x <= hs2->left_op->pt.x) + hs1->left_op = hs1->left_op->prev; + while (hs2->left_op->next->pt.y == curr_y && + hs2->left_op->next->pt.x <= hs1->left_op->pt.x) + hs2->left_op = hs2->left_op->next; + HorzJoin join = HorzJoin( + DuplicateOp(hs2->left_op, true), + DuplicateOp(hs1->left_op, false)); + horz_join_list_.push_back(join); + } + } + } + } + + void ClipperBase::ProcessHorzJoins() + { + for (const HorzJoin& j : horz_join_list_) + { + OutRec* or1 = GetRealOutRec(j.op1->outrec); + OutRec* or2 = GetRealOutRec(j.op2->outrec); + + OutPt* op1b = j.op1->next; + OutPt* op2b = j.op2->prev; + j.op1->next = j.op2; + j.op2->prev = j.op1; + op1b->prev = op2b; + op2b->next = op1b; + + if (or1 == or2) + { + or2 = new OutRec(); + or2->pts = op1b; + FixOutRecPts(or2); + if (or1->pts->outrec == or2) + { + or1->pts = j.op1; + or1->pts->outrec = or1; + } + + if (using_polytree_) + { + if (Path1InsidePath2(or2->pts, or1->pts)) + SetOwner(or2, or1); + else if (Path1InsidePath2(or1->pts, or2->pts)) + SetOwner(or1, or2); + else + or2->owner = or1; + } + else + or2->owner = or1; + + outrec_list_.push_back(or2); + } + else + { + or2->pts = nullptr; + if (using_polytree_) + SetOwner(or2, or1); + else + or2->owner = or1; + } + } + } + + void ClipperBase::DoIntersections(const int64_t top_y) + { + if (BuildIntersectList(top_y)) + { + ProcessIntersectList(); + intersect_nodes_.clear(); + } + } + + void ClipperBase::AddNewIntersectNode(Active& e1, Active& e2, int64_t top_y) + { + Point64 ip; + if (!GetIntersectPoint(e1.bot, e1.top, e2.bot, e2.top, ip)) + ip = Point64(e1.curr_x, top_y); //parallel edges + + //rounding errors can occasionally place the calculated intersection + //point either below or above the scanbeam, so check and correct ... + if (ip.y > bot_y_ || ip.y < top_y) + { + double abs_dx1 = std::fabs(e1.dx); + double abs_dx2 = std::fabs(e2.dx); + if (abs_dx1 > 100 && abs_dx2 > 100) + { + if (abs_dx1 > abs_dx2) + ip = GetClosestPointOnSegment(ip, e1.bot, e1.top); + else + ip = GetClosestPointOnSegment(ip, e2.bot, e2.top); + } + else if (abs_dx1 > 100) + ip = GetClosestPointOnSegment(ip, e1.bot, e1.top); + else if (abs_dx2 > 100) + ip = GetClosestPointOnSegment(ip, e2.bot, e2.top); + else + { + if (ip.y < top_y) ip.y = top_y; + else ip.y = bot_y_; + if (abs_dx1 < abs_dx2) ip.x = TopX(e1, ip.y); + else ip.x = TopX(e2, ip.y); + } + } + intersect_nodes_.push_back(IntersectNode(&e1, &e2, ip)); + } + + bool ClipperBase::BuildIntersectList(const int64_t top_y) + { + if (!actives_ || !actives_->next_in_ael) return false; + + //Calculate edge positions at the top of the current scanbeam, and from this + //we will determine the intersections required to reach these new positions. + AdjustCurrXAndCopyToSEL(top_y); + //Find all edge intersections in the current scanbeam using a stable merge + //sort that ensures only adjacent edges are intersecting. Intersect info is + //stored in FIntersectList ready to be processed in ProcessIntersectList. + //Re merge sorts see https://stackoverflow.com/a/46319131/359538 + + Active* left = sel_, * right, * l_end, * r_end, * curr_base, * tmp; + + while (left && left->jump) + { + Active* prev_base = nullptr; + while (left && left->jump) + { + curr_base = left; + right = left->jump; + l_end = right; + r_end = right->jump; + left->jump = r_end; + while (left != l_end && right != r_end) + { + if (right->curr_x < left->curr_x) + { + tmp = right->prev_in_sel; + for (; ; ) + { + AddNewIntersectNode(*tmp, *right, top_y); + if (tmp == left) break; + tmp = tmp->prev_in_sel; + } + + tmp = right; + right = ExtractFromSEL(tmp); + l_end = right; + Insert1Before2InSEL(tmp, left); + if (left == curr_base) + { + curr_base = tmp; + curr_base->jump = r_end; + if (!prev_base) sel_ = curr_base; + else prev_base->jump = curr_base; + } + } + else left = left->next_in_sel; + } + prev_base = curr_base; + left = r_end; + } + left = sel_; + } + return intersect_nodes_.size() > 0; + } + + void ClipperBase::ProcessIntersectList() + { + //We now have a list of intersections required so that edges will be + //correctly positioned at the top of the scanbeam. However, it's important + //that edge intersections are processed from the bottom up, but it's also + //crucial that intersections only occur between adjacent edges. + + //First we do a quicksort so intersections proceed in a bottom up order ... + std::sort(intersect_nodes_.begin(), intersect_nodes_.end(), IntersectListSort); + //Now as we process these intersections, we must sometimes adjust the order + //to ensure that intersecting edges are always adjacent ... + + IntersectNodeList::iterator node_iter, node_iter2; + for (node_iter = intersect_nodes_.begin(); + node_iter != intersect_nodes_.end(); ++node_iter) + { + if (!EdgesAdjacentInAEL(*node_iter)) + { + node_iter2 = node_iter + 1; + while (!EdgesAdjacentInAEL(*node_iter2)) ++node_iter2; + std::swap(*node_iter, *node_iter2); + } + + IntersectNode& node = *node_iter; + IntersectEdges(*node.edge1, *node.edge2, node.pt); + SwapPositionsInAEL(*node.edge1, *node.edge2); + + node.edge1->curr_x = node.pt.x; + node.edge2->curr_x = node.pt.x; + CheckJoinLeft(*node.edge2, node.pt, true); + CheckJoinRight(*node.edge1, node.pt, true); + } + } + + void ClipperBase::SwapPositionsInAEL(Active& e1, Active& e2) + { + //preconditon: e1 must be immediately to the left of e2 + Active* next = e2.next_in_ael; + if (next) next->prev_in_ael = &e1; + Active* prev = e1.prev_in_ael; + if (prev) prev->next_in_ael = &e2; + e2.prev_in_ael = prev; + e2.next_in_ael = &e1; + e1.prev_in_ael = &e2; + e1.next_in_ael = next; + if (!e2.prev_in_ael) actives_ = &e2; + } + + inline OutPt* GetLastOp(const Active& hot_edge) + { + OutRec* outrec = hot_edge.outrec; + OutPt* result = outrec->pts; + if (&hot_edge != outrec->front_edge) + result = result->next; + return result; + } + + void ClipperBase::AddTrialHorzJoin(OutPt* op) + { + if (op->outrec->is_open) return; + horz_seg_list_.push_back(HorzSegment(op)); + } + + bool ClipperBase::ResetHorzDirection(const Active& horz, + const Vertex* max_vertex, int64_t& horz_left, int64_t& horz_right) + { + if (horz.bot.x == horz.top.x) + { + //the horizontal edge is going nowhere ... + horz_left = horz.curr_x; + horz_right = horz.curr_x; + Active* e = horz.next_in_ael; + while (e && e->vertex_top != max_vertex) e = e->next_in_ael; + return e != nullptr; + } + else if (horz.curr_x < horz.top.x) + { + horz_left = horz.curr_x; + horz_right = horz.top.x; + return true; + } + else + { + horz_left = horz.top.x; + horz_right = horz.curr_x; + return false; // right to left + } + } + + inline bool HorzIsSpike(const Active& horzEdge) + { + Point64 nextPt = NextVertex(horzEdge)->pt; + return (nextPt.y == horzEdge.bot.y) && + (horzEdge.bot.x < horzEdge.top.x) != (horzEdge.top.x < nextPt.x); + } + + inline void TrimHorz(Active& horzEdge, bool preserveCollinear) + { + bool wasTrimmed = false; + Point64 pt = NextVertex(horzEdge)->pt; + while (pt.y == horzEdge.top.y) + { + //always trim 180 deg. spikes (in closed paths) + //but otherwise break if preserveCollinear = true + if (preserveCollinear && + ((pt.x < horzEdge.top.x) != (horzEdge.bot.x < horzEdge.top.x))) + break; + + horzEdge.vertex_top = NextVertex(horzEdge); + horzEdge.top = pt; + wasTrimmed = true; + if (IsMaxima(horzEdge)) break; + pt = NextVertex(horzEdge)->pt; + } + + if (wasTrimmed) SetDx(horzEdge); // +/-infinity + } + + void ClipperBase::DoHorizontal(Active& horz) + /******************************************************************************* + * 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 the bottom vertices of * + * other HEs[#] and with non-horizontal edges [*]. Once these intersections * + * are completed, intermediate HEs are 'promoted' to the next edge in their * + * bounds, and they in turn may be intersected[%] by other HEs. * + * * + * eg: 3 horizontals at a scanline: / | / / * + * | / | (HE3)o ========%========== o * + * o ======= o(HE2) / | / / * + * o ============#=========*======*========#=========o (HE1) * + * / | / | / * + *******************************************************************************/ + { + Point64 pt; + bool horzIsOpen = IsOpen(horz); + int64_t y = horz.bot.y; + Vertex* vertex_max; + if (horzIsOpen) + vertex_max = GetCurrYMaximaVertex_Open(horz); + else + vertex_max = GetCurrYMaximaVertex(horz); + + // remove 180 deg.spikes and also simplify + // consecutive horizontals when PreserveCollinear = true + if (vertex_max && !horzIsOpen && vertex_max != horz.vertex_top) + TrimHorz(horz, PreserveCollinear); + + int64_t horz_left, horz_right; + bool is_left_to_right = + ResetHorzDirection(horz, vertex_max, horz_left, horz_right); + + if (IsHotEdge(horz)) + { +#ifdef USINGZ + OutPt* op = AddOutPt(horz, Point64(horz.curr_x, y, horz.bot.z)); +#else + OutPt* op = AddOutPt(horz, Point64(horz.curr_x, y)); +#endif + AddTrialHorzJoin(op); + } + OutRec* currHorzOutrec = horz.outrec; + + while (true) // loop through consec. horizontal edges + { + Active* e; + if (is_left_to_right) e = horz.next_in_ael; + else e = horz.prev_in_ael; + + while (e) + { + if (e->vertex_top == vertex_max) + { + if (IsHotEdge(horz) && IsJoined(*e)) + Split(*e, e->top); + + if (IsHotEdge(horz)) + { + while (horz.vertex_top != vertex_max) + { + AddOutPt(horz, horz.top); + UpdateEdgeIntoAEL(&horz); + } + if (is_left_to_right) + AddLocalMaxPoly(horz, *e, horz.top); + else + AddLocalMaxPoly(*e, horz, horz.top); + } + DeleteFromAEL(*e); + DeleteFromAEL(horz); + return; + } + + //if horzEdge is a maxima, keep going until we reach + //its maxima pair, otherwise check for break conditions + if (vertex_max != horz.vertex_top || IsOpenEnd(horz)) + { + //otherwise stop when 'ae' is beyond the end of the horizontal line + if ((is_left_to_right && e->curr_x > horz_right) || + (!is_left_to_right && e->curr_x < horz_left)) break; + + if (e->curr_x == horz.top.x && !IsHorizontal(*e)) + { + pt = NextVertex(horz)->pt; + if (is_left_to_right) + { + //with open paths we'll only break once past horz's end + if (IsOpen(*e) && !IsSamePolyType(*e, horz) && !IsHotEdge(*e)) + { + if (TopX(*e, pt.y) > pt.x) break; + } + //otherwise we'll only break when horz's outslope is greater than e's + else if (TopX(*e, pt.y) >= pt.x) break; + } + else + { + if (IsOpen(*e) && !IsSamePolyType(*e, horz) && !IsHotEdge(*e)) + { + if (TopX(*e, pt.y) < pt.x) break; + } + else if (TopX(*e, pt.y) <= pt.x) break; + } + } + } + + pt = Point64(e->curr_x, horz.bot.y); + if (is_left_to_right) + { + IntersectEdges(horz, *e, pt); + SwapPositionsInAEL(horz, *e); + horz.curr_x = e->curr_x; + e = horz.next_in_ael; + } + else + { + IntersectEdges(*e, horz, pt); + SwapPositionsInAEL(*e, horz); + horz.curr_x = e->curr_x; + e = horz.prev_in_ael; + } + + if (horz.outrec && horz.outrec != currHorzOutrec) + { + currHorzOutrec = horz.outrec; + //nb: The outrec containining the op returned by IntersectEdges + //above may no longer be associated with horzEdge. + AddTrialHorzJoin(GetLastOp(horz)); + } + } + + //check if we've finished with (consecutive) horizontals ... + if (horzIsOpen && IsOpenEnd(horz)) // ie open at top + { + if (IsHotEdge(horz)) + { + AddOutPt(horz, horz.top); + if (IsFront(horz)) + horz.outrec->front_edge = nullptr; + else + horz.outrec->back_edge = nullptr; + horz.outrec = nullptr; + } + DeleteFromAEL(horz); + return; + } + else if (NextVertex(horz)->pt.y != horz.top.y) + break; + + //still more horizontals in bound to process ... + if (IsHotEdge(horz)) + AddOutPt(horz, horz.top); + UpdateEdgeIntoAEL(&horz); + + if (PreserveCollinear && !horzIsOpen && HorzIsSpike(horz)) + TrimHorz(horz, true); + + is_left_to_right = + ResetHorzDirection(horz, vertex_max, horz_left, horz_right); + } + + if (IsHotEdge(horz)) AddOutPt(horz, horz.top); + UpdateEdgeIntoAEL(&horz); // end of an intermediate horiz. + } + + void ClipperBase::DoTopOfScanbeam(const int64_t y) + { + sel_ = nullptr; // sel_ is reused to flag horizontals (see PushHorz below) + Active* e = actives_; + while (e) + { + //nb: 'e' will never be horizontal here + if (e->top.y == y) + { + e->curr_x = e->top.x; + if (IsMaxima(*e)) + { + e = DoMaxima(*e); // TOP OF BOUND (MAXIMA) + continue; + } + else + { + //INTERMEDIATE VERTEX ... + if (IsHotEdge(*e)) AddOutPt(*e, e->top); + UpdateEdgeIntoAEL(e); + if (IsHorizontal(*e)) + PushHorz(*e); // horizontals are processed later + } + } + else // i.e. not the top of the edge + e->curr_x = TopX(*e, y); + + e = e->next_in_ael; + } + } + + + Active* ClipperBase::DoMaxima(Active& e) + { + Active* next_e, * prev_e, * max_pair; + prev_e = e.prev_in_ael; + next_e = e.next_in_ael; + if (IsOpenEnd(e)) + { + if (IsHotEdge(e)) AddOutPt(e, e.top); + if (!IsHorizontal(e)) + { + if (IsHotEdge(e)) + { + if (IsFront(e)) + e.outrec->front_edge = nullptr; + else + e.outrec->back_edge = nullptr; + e.outrec = nullptr; + } + DeleteFromAEL(e); + } + return next_e; + } + + max_pair = GetMaximaPair(e); + if (!max_pair) return next_e; // eMaxPair is horizontal + + if (IsJoined(e)) Split(e, e.top); + if (IsJoined(*max_pair)) Split(*max_pair, max_pair->top); + + //only non-horizontal maxima here. + //process any edges between maxima pair ... + while (next_e != max_pair) + { + IntersectEdges(e, *next_e, e.top); + SwapPositionsInAEL(e, *next_e); + next_e = e.next_in_ael; + } + + if (IsOpen(e)) + { + if (IsHotEdge(e)) + AddLocalMaxPoly(e, *max_pair, e.top); + DeleteFromAEL(*max_pair); + DeleteFromAEL(e); + return (prev_e ? prev_e->next_in_ael : actives_); + } + + // e.next_in_ael== max_pair ... + if (IsHotEdge(e)) + AddLocalMaxPoly(e, *max_pair, e.top); + + DeleteFromAEL(e); + DeleteFromAEL(*max_pair); + return (prev_e ? prev_e->next_in_ael : actives_); + } + + void ClipperBase::Split(Active& e, const Point64& pt) + { + if (e.join_with == JoinWith::Right) + { + e.join_with = JoinWith::None; + e.next_in_ael->join_with = JoinWith::None; + AddLocalMinPoly(e, *e.next_in_ael, pt, true); + } + else + { + e.join_with = JoinWith::None; + e.prev_in_ael->join_with = JoinWith::None; + AddLocalMinPoly(*e.prev_in_ael, e, pt, true); + } + } + + void ClipperBase::CheckJoinLeft(Active& e, + const Point64& pt, bool check_curr_x) + { + Active* prev = e.prev_in_ael; + if (IsOpen(e) || !IsHotEdge(e) || !prev || + IsOpen(*prev) || !IsHotEdge(*prev) || + pt.y < e.top.y + 2 || pt.y < prev->top.y + 2) // avoid trivial joins + return; + + if (check_curr_x) + { + if (DistanceFromLineSqrd(pt, prev->bot, prev->top) > 0.25) return; + } + else if (e.curr_x != prev->curr_x) return; + if (CrossProduct(e.top, pt, prev->top)) return; + + if (e.outrec->idx == prev->outrec->idx) + AddLocalMaxPoly(*prev, e, pt); + else if (e.outrec->idx < prev->outrec->idx) + JoinOutrecPaths(e, *prev); + else + JoinOutrecPaths(*prev, e); + prev->join_with = JoinWith::Right; + e.join_with = JoinWith::Left; + } + + void ClipperBase::CheckJoinRight(Active& e, + const Point64& pt, bool check_curr_x) + { + Active* next = e.next_in_ael; + if (IsOpen(e) || !IsHotEdge(e) || + !next || IsOpen(*next) || !IsHotEdge(*next) || + pt.y < e.top.y +2 || pt.y < next->top.y +2) // avoids trivial joins + return; + + if (check_curr_x) + { + if (DistanceFromLineSqrd(pt, next->bot, next->top) > 0.35) return; + } + else if (e.curr_x != next->curr_x) return; + if (CrossProduct(e.top, pt, next->top)) return; + + if (e.outrec->idx == next->outrec->idx) + AddLocalMaxPoly(e, *next, pt); + else if (e.outrec->idx < next->outrec->idx) + JoinOutrecPaths(e, *next); + else + JoinOutrecPaths(*next, e); + e.join_with = JoinWith::Right; + next->join_with = JoinWith::Left; + } + + inline bool GetHorzExtendedHorzSeg(OutPt*& op, OutPt*& op2) + { + OutRec* outrec = GetRealOutRec(op->outrec); + op2 = op; + if (outrec->front_edge) + { + while (op->prev != outrec->pts && + op->prev->pt.y == op->pt.y) op = op->prev; + while (op2 != outrec->pts && + op2->next->pt.y == op2->pt.y) op2 = op2->next; + return op2 != op; + } + else + { + while (op->prev != op2 && op->prev->pt.y == op->pt.y) + op = op->prev; + while (op2->next != op && op2->next->pt.y == op2->pt.y) + op2 = op2->next; + return op2 != op && op2->next != op; + } + } + + bool BuildPath64(OutPt* op, bool reverse, bool isOpen, Path64& path) + { + if (!op || op->next == op || (!isOpen && op->next == op->prev)) + return false; + + path.resize(0); + Point64 lastPt; + OutPt* op2; + if (reverse) + { + lastPt = op->pt; + op2 = op->prev; + } + else + { + op = op->next; + lastPt = op->pt; + op2 = op->next; + } + path.push_back(lastPt); + + while (op2 != op) + { + if (op2->pt != lastPt) + { + lastPt = op2->pt; + path.push_back(lastPt); + } + if (reverse) + op2 = op2->prev; + else + op2 = op2->next; + } + + if (path.size() == 3 && IsVerySmallTriangle(*op2)) return false; + else return true; + } + + bool ClipperBase::CheckBounds(OutRec* outrec) + { + if (!outrec->pts) return false; + if (!outrec->bounds.IsEmpty()) return true; + CleanCollinear(outrec); + if (!outrec->pts || + !BuildPath64(outrec->pts, ReverseSolution, false, outrec->path)) + return false; + outrec->bounds = GetBounds(outrec->path); + return true; + } + + void ClipperBase::RecursiveCheckOwners(OutRec* outrec, PolyPath* polypath) + { + // pre-condition: outrec will have valid bounds + // post-condition: if a valid path, outrec will have a polypath + + if (outrec->polypath || outrec->bounds.IsEmpty()) return; + + while (outrec->owner && + (!outrec->owner->pts || !CheckBounds(outrec->owner))) + outrec->owner = outrec->owner->owner; + + if (outrec->owner && !outrec->owner->polypath) + RecursiveCheckOwners(outrec->owner, polypath); + + while (outrec->owner) + if (outrec->owner->bounds.Contains(outrec->bounds) && + Path1InsidePath2(outrec->pts, outrec->owner->pts)) + break; // found - owner contain outrec! + else + outrec->owner = outrec->owner->owner; + + if (outrec->owner) + outrec->polypath = outrec->owner->polypath->AddChild(outrec->path); + else + outrec->polypath = polypath->AddChild(outrec->path); + } + + void ClipperBase::DeepCheckOwners(OutRec* outrec, PolyPath* polypath) + { + RecursiveCheckOwners(outrec, polypath); + + while (outrec->owner && outrec->owner->splits) + { + OutRec* split = nullptr; + for (auto s : *outrec->owner->splits) + { + split = GetRealOutRec(s); + if (split && split != outrec && + split != outrec->owner && CheckBounds(split) && + split->bounds.Contains(outrec->bounds) && + Path1InsidePath2(outrec->pts, split->pts)) + { + RecursiveCheckOwners(split, polypath); + outrec->owner = split; //found in split + break; // inner 'for' loop + } + else + split = nullptr; + } + if (!split) break; + } + } + + void Clipper64::BuildPaths64(Paths64& solutionClosed, Paths64* solutionOpen) + { + solutionClosed.resize(0); + solutionClosed.reserve(outrec_list_.size()); + if (solutionOpen) + { + solutionOpen->resize(0); + solutionOpen->reserve(outrec_list_.size()); + } + + // nb: outrec_list_.size() may change in the following + // while loop because polygons may be split during + // calls to CleanCollinear which calls FixSelfIntersects + for (size_t i = 0; i < outrec_list_.size(); ++i) + { + OutRec* outrec = outrec_list_[i]; + if (outrec->pts == nullptr) continue; + + Path64 path; + if (solutionOpen && outrec->is_open) + { + if (BuildPath64(outrec->pts, ReverseSolution, true, path)) + solutionOpen->emplace_back(std::move(path)); + } + else + { + // nb: CleanCollinear can add to outrec_list_ + CleanCollinear(outrec); + //closed paths should always return a Positive orientation + if (BuildPath64(outrec->pts, ReverseSolution, false, path)) + solutionClosed.emplace_back(std::move(path)); + } + } + } + + void Clipper64::BuildTree64(PolyPath64& polytree, Paths64& open_paths) + { + polytree.Clear(); + open_paths.resize(0); + if (has_open_paths_) + open_paths.reserve(outrec_list_.size()); + + // outrec_list_.size() is not static here because + // CheckBounds below can indirectly add additional + // OutRec (via FixOutRecPts & CleanCollinear) + for (size_t i = 0; i < outrec_list_.size(); ++i) + { + OutRec* outrec = outrec_list_[i]; + if (!outrec || !outrec->pts) continue; + if (outrec->is_open) + { + Path64 path; + if (BuildPath64(outrec->pts, ReverseSolution, true, path)) + open_paths.push_back(path); + continue; + } + + if (CheckBounds(outrec)) + DeepCheckOwners(outrec, &polytree); + } + } + + bool BuildPathD(OutPt* op, bool reverse, bool isOpen, PathD& path, double inv_scale) + { + if (!op || op->next == op || (!isOpen && op->next == op->prev)) + return false; + + path.resize(0); + Point64 lastPt; + OutPt* op2; + if (reverse) + { + lastPt = op->pt; + op2 = op->prev; + } + else + { + op = op->next; + lastPt = op->pt; + op2 = op->next; + } +#ifdef USINGZ + path.push_back(PointD(lastPt.x * inv_scale, lastPt.y * inv_scale, lastPt.z)); +#else + path.push_back(PointD(lastPt.x * inv_scale, lastPt.y * inv_scale)); +#endif + + while (op2 != op) + { + if (op2->pt != lastPt) + { + lastPt = op2->pt; +#ifdef USINGZ + path.push_back(PointD(lastPt.x * inv_scale, lastPt.y * inv_scale, lastPt.z)); +#else + path.push_back(PointD(lastPt.x * inv_scale, lastPt.y * inv_scale)); +#endif + + } + if (reverse) + op2 = op2->prev; + else + op2 = op2->next; + } + if (path.size() == 3 && IsVerySmallTriangle(*op2)) return false; + return true; + } + + void ClipperD::BuildPathsD(PathsD& solutionClosed, PathsD* solutionOpen) + { + solutionClosed.resize(0); + solutionClosed.reserve(outrec_list_.size()); + if (solutionOpen) + { + solutionOpen->resize(0); + solutionOpen->reserve(outrec_list_.size()); + } + + // outrec_list_.size() is not static here because + // CleanCollinear below can indirectly add additional + // OutRec (via FixOutRecPts) + for (std::size_t i = 0; i < outrec_list_.size(); ++i) + { + OutRec* outrec = outrec_list_[i]; + if (outrec->pts == nullptr) continue; + + PathD path; + if (solutionOpen && outrec->is_open) + { + if (BuildPathD(outrec->pts, ReverseSolution, true, path, invScale_)) + solutionOpen->emplace_back(std::move(path)); + } + else + { + CleanCollinear(outrec); + //closed paths should always return a Positive orientation + if (BuildPathD(outrec->pts, ReverseSolution, false, path, invScale_)) + solutionClosed.emplace_back(std::move(path)); + } + } + } + + void ClipperD::BuildTreeD(PolyPathD& polytree, PathsD& open_paths) + { + polytree.Clear(); + open_paths.resize(0); + if (has_open_paths_) + open_paths.reserve(outrec_list_.size()); + + for (OutRec* outrec : outrec_list_) + { + if (!outrec || !outrec->pts) continue; + if (outrec->is_open) + { + PathD path; + if (BuildPathD(outrec->pts, ReverseSolution, true, path, invScale_)) + open_paths.push_back(path); + continue; + } + + if (CheckBounds(outrec)) + DeepCheckOwners(outrec, &polytree); + } + } + +} // namespace clipper2lib -- cgit v1.2.3