godot/thirdparty/clipper2/include/clipper2/clipper.engine.h

611 lines
18 KiB
C++

/*******************************************************************************
* Author : Angus Johnson *
* Date : 26 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 *
*******************************************************************************/
#ifndef CLIPPER_ENGINE_H
#define CLIPPER_ENGINE_H
constexpr auto CLIPPER2_VERSION = "1.2.2";
#include <cstdlib>
#include <iostream>
#include <queue>
#include <vector>
#include <functional>
#include <numeric>
#include <memory>
#include "clipper.core.h"
namespace Clipper2Lib {
struct Scanline;
struct IntersectNode;
struct Active;
struct Vertex;
struct LocalMinima;
struct OutRec;
struct HorzSegment;
//Note: all clipping operations except for Difference are commutative.
enum class ClipType { None, Intersection, Union, Difference, Xor };
enum class PathType { Subject, Clip };
enum class JoinWith { None, Left, Right };
enum class VertexFlags : uint32_t {
None = 0, OpenStart = 1, OpenEnd = 2, LocalMax = 4, LocalMin = 8
};
constexpr enum VertexFlags operator &(enum VertexFlags a, enum VertexFlags b)
{
return (enum VertexFlags)(uint32_t(a) & uint32_t(b));
}
constexpr enum VertexFlags operator |(enum VertexFlags a, enum VertexFlags b)
{
return (enum VertexFlags)(uint32_t(a) | uint32_t(b));
}
struct Vertex {
Point64 pt;
Vertex* next = nullptr;
Vertex* prev = nullptr;
VertexFlags flags = VertexFlags::None;
};
struct OutPt {
Point64 pt;
OutPt* next = nullptr;
OutPt* prev = nullptr;
OutRec* outrec;
HorzSegment* horz = nullptr;
OutPt(const Point64& pt_, OutRec* outrec_): pt(pt_), outrec(outrec_) {
next = this;
prev = this;
}
};
class PolyPath;
class PolyPath64;
class PolyPathD;
using PolyTree64 = PolyPath64;
using PolyTreeD = PolyPathD;
struct OutRec;
typedef std::vector<OutRec*> OutRecList;
//OutRec: contains a path in the clipping solution. Edges in the AEL will
//have OutRec pointers assigned when they form part of the clipping solution.
struct OutRec {
size_t idx = 0;
OutRec* owner = nullptr;
Active* front_edge = nullptr;
Active* back_edge = nullptr;
OutPt* pts = nullptr;
PolyPath* polypath = nullptr;
OutRecList* splits = nullptr;
Rect64 bounds = {};
Path64 path;
bool is_open = false;
bool horz_done = false;
~OutRec() {
if (splits) delete splits;
// nb: don't delete the split pointers
// as these are owned by ClipperBase's outrec_list_
};
};
///////////////////////////////////////////////////////////////////
//Important: UP and DOWN here are premised on Y-axis positive down
//displays, which is the orientation used in Clipper's development.
///////////////////////////////////////////////////////////////////
struct Active {
Point64 bot;
Point64 top;
int64_t curr_x = 0; //current (updated at every new scanline)
double dx = 0.0;
int wind_dx = 1; //1 or -1 depending on winding direction
int wind_cnt = 0;
int wind_cnt2 = 0; //winding count of the opposite polytype
OutRec* outrec = nullptr;
//AEL: 'active edge list' (Vatti's AET - active edge table)
// a linked list of all edges (from left to right) that are present
// (or 'active') within the current scanbeam (a horizontal 'beam' that
// sweeps from bottom to top over the paths in the clipping operation).
Active* prev_in_ael = nullptr;
Active* next_in_ael = nullptr;
//SEL: 'sorted edge list' (Vatti's ST - sorted table)
// linked list used when sorting edges into their new positions at the
// top of scanbeams, but also (re)used to process horizontals.
Active* prev_in_sel = nullptr;
Active* next_in_sel = nullptr;
Active* jump = nullptr;
Vertex* vertex_top = nullptr;
LocalMinima* local_min = nullptr; // the bottom of an edge 'bound' (also Vatti)
bool is_left_bound = false;
JoinWith join_with = JoinWith::None;
};
struct LocalMinima {
Vertex* vertex;
PathType polytype;
bool is_open;
LocalMinima(Vertex* v, PathType pt, bool open) :
vertex(v), polytype(pt), is_open(open){}
};
struct IntersectNode {
Point64 pt;
Active* edge1;
Active* edge2;
IntersectNode() : pt(Point64(0,0)), edge1(NULL), edge2(NULL) {}
IntersectNode(Active* e1, Active* e2, Point64& pt_) :
pt(pt_), edge1(e1), edge2(e2) {}
};
struct HorzSegment {
OutPt* left_op;
OutPt* right_op = nullptr;
bool left_to_right = true;
HorzSegment() : left_op(nullptr) { }
explicit HorzSegment(OutPt* op) : left_op(op) { }
};
struct HorzJoin {
OutPt* op1 = nullptr;
OutPt* op2 = nullptr;
HorzJoin() {};
explicit HorzJoin(OutPt* ltr, OutPt* rtl) : op1(ltr), op2(rtl) { }
};
#ifdef USINGZ
typedef std::function<void(const Point64& e1bot, const Point64& e1top,
const Point64& e2bot, const Point64& e2top, Point64& pt)> ZCallback64;
typedef std::function<void(const PointD& e1bot, const PointD& e1top,
const PointD& e2bot, const PointD& e2top, PointD& pt)> ZCallbackD;
#endif
typedef std::vector<HorzSegment> HorzSegmentList;
typedef std::unique_ptr<LocalMinima> LocalMinima_ptr;
typedef std::vector<LocalMinima_ptr> LocalMinimaList;
typedef std::vector<IntersectNode> IntersectNodeList;
// ClipperBase -------------------------------------------------------------
class ClipperBase {
private:
ClipType cliptype_ = ClipType::None;
FillRule fillrule_ = FillRule::EvenOdd;
FillRule fillpos = FillRule::Positive;
int64_t bot_y_ = 0;
bool minima_list_sorted_ = false;
bool using_polytree_ = false;
Active* actives_ = nullptr;
Active *sel_ = nullptr;
LocalMinimaList minima_list_; //pointers in case of memory reallocs
LocalMinimaList::iterator current_locmin_iter_;
std::vector<Vertex*> vertex_lists_;
std::priority_queue<int64_t> scanline_list_;
IntersectNodeList intersect_nodes_;
HorzSegmentList horz_seg_list_;
std::vector<HorzJoin> horz_join_list_;
void Reset();
inline void InsertScanline(int64_t y);
inline bool PopScanline(int64_t &y);
inline bool PopLocalMinima(int64_t y, LocalMinima*& local_minima);
void DisposeAllOutRecs();
void DisposeVerticesAndLocalMinima();
void DeleteEdges(Active*& e);
inline void AddLocMin(Vertex &vert, PathType polytype, bool is_open);
bool IsContributingClosed(const Active &e) const;
inline bool IsContributingOpen(const Active &e) const;
void SetWindCountForClosedPathEdge(Active &edge);
void SetWindCountForOpenPathEdge(Active &e);
void InsertLocalMinimaIntoAEL(int64_t bot_y);
void InsertLeftEdge(Active &e);
inline void PushHorz(Active &e);
inline bool PopHorz(Active *&e);
inline OutPt* StartOpenPath(Active &e, const Point64& pt);
inline void UpdateEdgeIntoAEL(Active *e);
OutPt* IntersectEdges(Active &e1, Active &e2, const Point64& pt);
inline void DeleteFromAEL(Active &e);
inline void AdjustCurrXAndCopyToSEL(const int64_t top_y);
void DoIntersections(const int64_t top_y);
void AddNewIntersectNode(Active &e1, Active &e2, const int64_t top_y);
bool BuildIntersectList(const int64_t top_y);
void ProcessIntersectList();
void SwapPositionsInAEL(Active& edge1, Active& edge2);
OutRec* NewOutRec();
OutPt* AddOutPt(const Active &e, const Point64& pt);
OutPt* AddLocalMinPoly(Active &e1, Active &e2,
const Point64& pt, bool is_new = false);
OutPt* AddLocalMaxPoly(Active &e1, Active &e2, const Point64& pt);
void DoHorizontal(Active &horz);
bool ResetHorzDirection(const Active &horz, const Vertex* max_vertex,
int64_t &horz_left, int64_t &horz_right);
void DoTopOfScanbeam(const int64_t top_y);
Active *DoMaxima(Active &e);
void JoinOutrecPaths(Active &e1, Active &e2);
void CompleteSplit(OutPt* op1, OutPt* op2, OutRec& outrec);
void FixSelfIntersects(OutRec* outrec);
void DoSplitOp(OutRec* outRec, OutPt* splitOp);
inline void AddTrialHorzJoin(OutPt* op);
void ConvertHorzSegsToJoins();
void ProcessHorzJoins();
void Split(Active& e, const Point64& pt);
inline void CheckJoinLeft(Active& e,
const Point64& pt, bool check_curr_x = false);
inline void CheckJoinRight(Active& e,
const Point64& pt, bool check_curr_x = false);
protected:
int error_code_ = 0;
bool has_open_paths_ = false;
bool succeeded_ = true;
OutRecList outrec_list_; //pointers in case list memory reallocated
bool ExecuteInternal(ClipType ct, FillRule ft, bool use_polytrees);
void CleanCollinear(OutRec* outrec);
bool CheckBounds(OutRec* outrec);
void RecursiveCheckOwners(OutRec* outrec, PolyPath* polypath);
void DeepCheckOwners(OutRec* outrec, PolyPath* polypath);
#ifdef USINGZ
ZCallback64 zCallback_ = nullptr;
void SetZ(const Active& e1, const Active& e2, Point64& pt);
#endif
void CleanUp(); // unlike Clear, CleanUp preserves added paths
void AddPath(const Path64& path, PathType polytype, bool is_open);
void AddPaths(const Paths64& paths, PathType polytype, bool is_open);
public:
virtual ~ClipperBase();
int ErrorCode() { return error_code_; };
bool PreserveCollinear = true;
bool ReverseSolution = false;
void Clear();
#ifdef USINGZ
int64_t DefaultZ = 0;
#endif
};
// PolyPath / PolyTree --------------------------------------------------------
//PolyTree: is intended as a READ-ONLY data structure for CLOSED paths returned
//by clipping operations. While this structure is more complex than the
//alternative Paths structure, it does preserve path 'ownership' - ie those
//paths that contain (or own) other paths. This will be useful to some users.
class PolyPath {
protected:
PolyPath* parent_;
public:
PolyPath(PolyPath* parent = nullptr): parent_(parent){}
virtual ~PolyPath() {};
//https://en.cppreference.com/w/cpp/language/rule_of_three
PolyPath(const PolyPath&) = delete;
PolyPath& operator=(const PolyPath&) = delete;
unsigned Level() const
{
unsigned result = 0;
const PolyPath* p = parent_;
while (p) { ++result; p = p->parent_; }
return result;
}
virtual PolyPath* AddChild(const Path64& path) = 0;
virtual void Clear() = 0;
virtual size_t Count() const { return 0; }
const PolyPath* Parent() const { return parent_; }
bool IsHole() const
{
unsigned lvl = Level();
//Even levels except level 0
return lvl && !(lvl & 1);
}
};
typedef typename std::vector<std::unique_ptr<PolyPath64>> PolyPath64List;
typedef typename std::vector<std::unique_ptr<PolyPathD>> PolyPathDList;
class PolyPath64 : public PolyPath {
private:
PolyPath64List childs_;
Path64 polygon_;
public:
explicit PolyPath64(PolyPath64* parent = nullptr) : PolyPath(parent) {}
~PolyPath64() {
childs_.resize(0);
}
const PolyPath64* operator [] (size_t index) const
{
return childs_[index].get();
}
const PolyPath64* Child(size_t index) const
{
return childs_[index].get();
}
PolyPath64List::const_iterator begin() const { return childs_.cbegin(); }
PolyPath64List::const_iterator end() const { return childs_.cend(); }
PolyPath64* AddChild(const Path64& path) override
{
auto p = std::make_unique<PolyPath64>(this);
auto* result = childs_.emplace_back(std::move(p)).get();
result->polygon_ = path;
return result;
}
void Clear() override
{
childs_.resize(0);
}
size_t Count() const override
{
return childs_.size();
}
const Path64& Polygon() const { return polygon_; };
double Area() const
{
return std::accumulate(childs_.cbegin(), childs_.cend(),
Clipper2Lib::Area<int64_t>(polygon_),
[](double a, const auto& child) {return a + child->Area(); });
}
};
class PolyPathD : public PolyPath {
private:
PolyPathDList childs_;
double inv_scale_;
PathD polygon_;
public:
explicit PolyPathD(PolyPathD* parent = nullptr) : PolyPath(parent)
{
inv_scale_ = parent ? parent->inv_scale_ : 1.0;
}
~PolyPathD() {
childs_.resize(0);
}
const PolyPathD* operator [] (size_t index) const
{
return childs_[index].get();
}
const PolyPathD* Child(size_t index) const
{
return childs_[index].get();
}
PolyPathDList::const_iterator begin() const { return childs_.cbegin(); }
PolyPathDList::const_iterator end() const { return childs_.cend(); }
void SetInvScale(double value) { inv_scale_ = value; }
double InvScale() { return inv_scale_; }
PolyPathD* AddChild(const Path64& path) override
{
int error_code = 0;
auto p = std::make_unique<PolyPathD>(this);
PolyPathD* result = childs_.emplace_back(std::move(p)).get();
result->polygon_ = ScalePath<double, int64_t>(path, inv_scale_, error_code);
return result;
}
void Clear() override
{
childs_.resize(0);
}
size_t Count() const override
{
return childs_.size();
}
const PathD& Polygon() const { return polygon_; };
double Area() const
{
return std::accumulate(childs_.begin(), childs_.end(),
Clipper2Lib::Area<double>(polygon_),
[](double a, const auto& child) {return a + child->Area(); });
}
};
class Clipper64 : public ClipperBase
{
private:
void BuildPaths64(Paths64& solutionClosed, Paths64* solutionOpen);
void BuildTree64(PolyPath64& polytree, Paths64& open_paths);
public:
#ifdef USINGZ
void SetZCallback(ZCallback64 cb) { zCallback_ = cb; }
#endif
void AddSubject(const Paths64& subjects)
{
AddPaths(subjects, PathType::Subject, false);
}
void AddOpenSubject(const Paths64& open_subjects)
{
AddPaths(open_subjects, PathType::Subject, true);
}
void AddClip(const Paths64& clips)
{
AddPaths(clips, PathType::Clip, false);
}
bool Execute(ClipType clip_type,
FillRule fill_rule, Paths64& closed_paths)
{
Paths64 dummy;
return Execute(clip_type, fill_rule, closed_paths, dummy);
}
bool Execute(ClipType clip_type, FillRule fill_rule,
Paths64& closed_paths, Paths64& open_paths)
{
closed_paths.clear();
open_paths.clear();
if (ExecuteInternal(clip_type, fill_rule, false))
BuildPaths64(closed_paths, &open_paths);
CleanUp();
return succeeded_;
}
bool Execute(ClipType clip_type, FillRule fill_rule, PolyTree64& polytree)
{
Paths64 dummy;
return Execute(clip_type, fill_rule, polytree, dummy);
}
bool Execute(ClipType clip_type,
FillRule fill_rule, PolyTree64& polytree, Paths64& open_paths)
{
if (ExecuteInternal(clip_type, fill_rule, true))
{
open_paths.clear();
polytree.Clear();
BuildTree64(polytree, open_paths);
}
CleanUp();
return succeeded_;
}
};
class ClipperD : public ClipperBase {
private:
double scale_ = 1.0, invScale_ = 1.0;
#ifdef USINGZ
ZCallbackD zCallbackD_ = nullptr;
#endif
void BuildPathsD(PathsD& solutionClosed, PathsD* solutionOpen);
void BuildTreeD(PolyPathD& polytree, PathsD& open_paths);
public:
explicit ClipperD(int precision = 2) : ClipperBase()
{
CheckPrecision(precision, error_code_);
// to optimize scaling / descaling precision
// set the scale to a power of double's radix (2) (#25)
scale_ = std::pow(std::numeric_limits<double>::radix,
std::ilogb(std::pow(10, precision)) + 1);
invScale_ = 1 / scale_;
}
#ifdef USINGZ
void SetZCallback(ZCallbackD cb) { zCallbackD_ = cb; };
void ZCB(const Point64& e1bot, const Point64& e1top,
const Point64& e2bot, const Point64& e2top, Point64& pt)
{
// de-scale (x & y)
// temporarily convert integers to their initial float values
// this will slow clipping marginally but will make it much easier
// to understand the coordinates passed to the callback function
PointD tmp = PointD(pt) * invScale_;
PointD e1b = PointD(e1bot) * invScale_;
PointD e1t = PointD(e1top) * invScale_;
PointD e2b = PointD(e2bot) * invScale_;
PointD e2t = PointD(e2top) * invScale_;
zCallbackD_(e1b,e1t, e2b, e2t, tmp);
pt.z = tmp.z; // only update 'z'
};
void CheckCallback()
{
if(zCallbackD_)
// if the user defined float point callback has been assigned
// then assign the proxy callback function
ClipperBase::zCallback_ =
std::bind(&ClipperD::ZCB, this, std::placeholders::_1,
std::placeholders::_2, std::placeholders::_3,
std::placeholders::_4, std::placeholders::_5);
else
ClipperBase::zCallback_ = nullptr;
}
#endif
void AddSubject(const PathsD& subjects)
{
AddPaths(ScalePaths<int64_t, double>(subjects, scale_, error_code_), PathType::Subject, false);
}
void AddOpenSubject(const PathsD& open_subjects)
{
AddPaths(ScalePaths<int64_t, double>(open_subjects, scale_, error_code_), PathType::Subject, true);
}
void AddClip(const PathsD& clips)
{
AddPaths(ScalePaths<int64_t, double>(clips, scale_, error_code_), PathType::Clip, false);
}
bool Execute(ClipType clip_type, FillRule fill_rule, PathsD& closed_paths)
{
PathsD dummy;
return Execute(clip_type, fill_rule, closed_paths, dummy);
}
bool Execute(ClipType clip_type,
FillRule fill_rule, PathsD& closed_paths, PathsD& open_paths)
{
#ifdef USINGZ
CheckCallback();
#endif
if (ExecuteInternal(clip_type, fill_rule, false))
{
BuildPathsD(closed_paths, &open_paths);
}
CleanUp();
return succeeded_;
}
bool Execute(ClipType clip_type, FillRule fill_rule, PolyTreeD& polytree)
{
PathsD dummy;
return Execute(clip_type, fill_rule, polytree, dummy);
}
bool Execute(ClipType clip_type,
FillRule fill_rule, PolyTreeD& polytree, PathsD& open_paths)
{
#ifdef USINGZ
CheckCallback();
#endif
if (ExecuteInternal(clip_type, fill_rule, true))
{
polytree.Clear();
polytree.SetInvScale(invScale_);
open_paths.clear();
BuildTreeD(polytree, open_paths);
}
CleanUp();
return succeeded_;
}
};
} // namespace
#endif // CLIPPER_ENGINE_H