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polygon: added poly2tri library. 

Requied for constrained Delaunay triangulation (P&S/ratsnest) and zone tesselation (GAL).
This commit is contained in:
tomasz.wlostowski@cern.ch 2013-09-13 15:28:20 +02:00
parent 7b0531fdd1
commit 228a9451f7
13 changed files with 2765 additions and 1 deletions
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6
polygon/CMakeLists.txt
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@ -9,6 +9,12 @@ set(POLYGON_SRCS
PolyLine.cpp
polygon_test_point_inside.cpp
clipper.cpp
poly2tri/common/shapes.cc
poly2tri/sweep/sweep.cc
poly2tri/sweep/cdt.cc
poly2tri/sweep/advancing_front.cc
poly2tri/sweep/sweep_context.cc
)
add_library(polygon STATIC ${POLYGON_SRCS})

367
polygon/poly2tri/common/shapes.cc Normal file
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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "shapes.h"
#include <iostream>
namespace p2t {
Triangle::Triangle(Point& a, Point& b, Point& c)
{
points_[0] = &a; points_[1] = &b; points_[2] = &c;
neighbors_[0] = NULL; neighbors_[1] = NULL; neighbors_[2] = NULL;
constrained_edge[0] = constrained_edge[1] = constrained_edge[2] = false;
delaunay_edge[0] = delaunay_edge[1] = delaunay_edge[2] = false;
interior_ = false;
}
// Update neighbor pointers
void Triangle::MarkNeighbor(Point* p1, Point* p2, Triangle* t)
{
if ((p1 == points_[2] && p2 == points_[1]) || (p1 == points_[1] && p2 == points_[2]))
neighbors_[0] = t;
else if ((p1 == points_[0] && p2 == points_[2]) || (p1 == points_[2] && p2 == points_[0]))
neighbors_[1] = t;
else if ((p1 == points_[0] && p2 == points_[1]) || (p1 == points_[1] && p2 == points_[0]))
neighbors_[2] = t;
else
assert(0);
}
// Exhaustive search to update neighbor pointers
void Triangle::MarkNeighbor(Triangle& t)
{
if (t.Contains(points_[1], points_[2])) {
neighbors_[0] = &t;
t.MarkNeighbor(points_[1], points_[2], this);
} else if (t.Contains(points_[0], points_[2])) {
neighbors_[1] = &t;
t.MarkNeighbor(points_[0], points_[2], this);
} else if (t.Contains(points_[0], points_[1])) {
neighbors_[2] = &t;
t.MarkNeighbor(points_[0], points_[1], this);
}
}
/**
* Clears all references to all other triangles and points
*/
void Triangle::Clear()
{
Triangle *t;
for( int i=0; i<3; i++ )
{
t = neighbors_[i];
if( t != NULL )
{
t->ClearNeighbor( this );
}
}
ClearNeighbors();
points_[0]=points_[1]=points_[2] = NULL;
}
void Triangle::ClearNeighbor(Triangle *triangle )
{
if( neighbors_[0] == triangle )
{
neighbors_[0] = NULL;
}
else if( neighbors_[1] == triangle )
{
neighbors_[1] = NULL;
}
else
{
neighbors_[2] = NULL;
}
}
void Triangle::ClearNeighbors()
{
neighbors_[0] = NULL;
neighbors_[1] = NULL;
neighbors_[2] = NULL;
}
void Triangle::ClearDelunayEdges()
{
delaunay_edge[0] = delaunay_edge[1] = delaunay_edge[2] = false;
}
Point* Triangle::OppositePoint(Triangle& t, Point& p)
{
Point *cw = t.PointCW(p);
double x = cw->x;
double y = cw->y;
x = p.x;
y = p.y;
return PointCW(*cw);
}
// Legalized triangle by rotating clockwise around point(0)
void Triangle::Legalize(Point& point)
{
points_[1] = points_[0];
points_[0] = points_[2];
points_[2] = &point;
}
// Legalize triagnle by rotating clockwise around oPoint
void Triangle::Legalize(Point& opoint, Point& npoint)
{
if (&opoint == points_[0]) {
points_[1] = points_[0];
points_[0] = points_[2];
points_[2] = &npoint;
} else if (&opoint == points_[1]) {
points_[2] = points_[1];
points_[1] = points_[0];
points_[0] = &npoint;
} else if (&opoint == points_[2]) {
points_[0] = points_[2];
points_[2] = points_[1];
points_[1] = &npoint;
} else {
assert(0);
}
}
int Triangle::Index(const Point* p)
{
if (p == points_[0]) {
return 0;
} else if (p == points_[1]) {
return 1;
} else if (p == points_[2]) {
return 2;
}
assert(0);
}
int Triangle::EdgeIndex(const Point* p1, const Point* p2)
{
if (points_[0] == p1) {
if (points_[1] == p2) {
return 2;
} else if (points_[2] == p2) {
return 1;
}
} else if (points_[1] == p1) {
if (points_[2] == p2) {
return 0;
} else if (points_[0] == p2) {
return 2;
}
} else if (points_[2] == p1) {
if (points_[0] == p2) {
return 1;
} else if (points_[1] == p2) {
return 0;
}
}
return -1;
}
void Triangle::MarkConstrainedEdge(const int index)
{
constrained_edge[index] = true;
}
void Triangle::MarkConstrainedEdge(Edge& edge)
{
MarkConstrainedEdge(edge.p, edge.q);
}
// Mark edge as constrained
void Triangle::MarkConstrainedEdge(Point* p, Point* q)
{
if ((q == points_[0] && p == points_[1]) || (q == points_[1] && p == points_[0])) {
constrained_edge[2] = true;
} else if ((q == points_[0] && p == points_[2]) || (q == points_[2] && p == points_[0])) {
constrained_edge[1] = true;
} else if ((q == points_[1] && p == points_[2]) || (q == points_[2] && p == points_[1])) {
constrained_edge[0] = true;
}
}
// The point counter-clockwise to given point
Point* Triangle::PointCW(Point& point)
{
if (&point == points_[0]) {
return points_[2];
} else if (&point == points_[1]) {
return points_[0];
} else if (&point == points_[2]) {
return points_[1];
}
assert(0);
}
// The point counter-clockwise to given point
Point* Triangle::PointCCW(Point& point)
{
if (&point == points_[0]) {
return points_[1];
} else if (&point == points_[1]) {
return points_[2];
} else if (&point == points_[2]) {
return points_[0];
}
assert(0);
}
// The neighbor clockwise to given point
Triangle* Triangle::NeighborCW(Point& point)
{
if (&point == points_[0]) {
return neighbors_[1];
} else if (&point == points_[1]) {
return neighbors_[2];
}
return neighbors_[0];
}
// The neighbor counter-clockwise to given point
Triangle* Triangle::NeighborCCW(Point& point)
{
if (&point == points_[0]) {
return neighbors_[2];
} else if (&point == points_[1]) {
return neighbors_[0];
}
return neighbors_[1];
}
bool Triangle::GetConstrainedEdgeCCW(Point& p)
{
if (&p == points_[0]) {
return constrained_edge[2];
} else if (&p == points_[1]) {
return constrained_edge[0];
}
return constrained_edge[1];
}
bool Triangle::GetConstrainedEdgeCW(Point& p)
{
if (&p == points_[0]) {
return constrained_edge[1];
} else if (&p == points_[1]) {
return constrained_edge[2];
}
return constrained_edge[0];
}
void Triangle::SetConstrainedEdgeCCW(Point& p, bool ce)
{
if (&p == points_[0]) {
constrained_edge[2] = ce;
} else if (&p == points_[1]) {
constrained_edge[0] = ce;
} else {
constrained_edge[1] = ce;
}
}
void Triangle::SetConstrainedEdgeCW(Point& p, bool ce)
{
if (&p == points_[0]) {
constrained_edge[1] = ce;
} else if (&p == points_[1]) {
constrained_edge[2] = ce;
} else {
constrained_edge[0] = ce;
}
}
bool Triangle::GetDelunayEdgeCCW(Point& p)
{
if (&p == points_[0]) {
return delaunay_edge[2];
} else if (&p == points_[1]) {
return delaunay_edge[0];
}
return delaunay_edge[1];
}
bool Triangle::GetDelunayEdgeCW(Point& p)
{
if (&p == points_[0]) {
return delaunay_edge[1];
} else if (&p == points_[1]) {
return delaunay_edge[2];
}
return delaunay_edge[0];
}
void Triangle::SetDelunayEdgeCCW(Point& p, bool e)
{
if (&p == points_[0]) {
delaunay_edge[2] = e;
} else if (&p == points_[1]) {
delaunay_edge[0] = e;
} else {
delaunay_edge[1] = e;
}
}
void Triangle::SetDelunayEdgeCW(Point& p, bool e)
{
if (&p == points_[0]) {
delaunay_edge[1] = e;
} else if (&p == points_[1]) {
delaunay_edge[2] = e;
} else {
delaunay_edge[0] = e;
}
}
// The neighbor across to given point
Triangle& Triangle::NeighborAcross(Point& opoint)
{
if (&opoint == points_[0]) {
return *neighbors_[0];
} else if (&opoint == points_[1]) {
return *neighbors_[1];
}
return *neighbors_[2];
}
void Triangle::DebugPrint()
{
using namespace std;
cout << points_[0]->x << "," << points_[0]->y << " ";
cout << points_[1]->x << "," << points_[1]->y << " ";
cout << points_[2]->x << "," << points_[2]->y << endl;
}
}

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polygon/poly2tri/common/shapes.h Normal file
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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// Include guard
#ifndef SHAPES_H
#define SHAPES_H
#include <vector>
#include <cstddef>
#include <assert.h>
#include <cmath>
namespace p2t {
struct Edge;
struct Point {
double x, y;
/// Default constructor does nothing (for performance).
Point()
{
x = 0.0;
y = 0.0;
}
/// The edges this point constitutes an upper ending point
std::vector<Edge*> edge_list;
/// Construct using coordinates.
Point(double x, double y) : x(x), y(y) {}
/// Set this point to all zeros.
void set_zero()
{
x = 0.0;
y = 0.0;
}
/// Set this point to some specified coordinates.
void set(double x_, double y_)
{
x = x_;
y = y_;
}
/// Negate this point.
Point operator -() const
{
Point v;
v.set(-x, -y);
return v;
}
/// Add a point to this point.
void operator +=(const Point& v)
{
x += v.x;
y += v.y;
}
/// Subtract a point from this point.
void operator -=(const Point& v)
{
x -= v.x;
y -= v.y;
}
/// Multiply this point by a scalar.
void operator *=(double a)
{
x *= a;
y *= a;
}
/// Get the length of this point (the norm).
double Length() const
{
return sqrt(x * x + y * y);
}
/// Convert this point into a unit point. Returns the Length.
double Normalize()
{
double len = Length();
x /= len;
y /= len;
return len;
}
};
// Represents a simple polygon's edge
struct Edge {
Point* p, *q;
/// Constructor
Edge(Point& p1, Point& p2) : p(&p1), q(&p2)
{
if (p1.y > p2.y) {
q = &p1;
p = &p2;
} else if (p1.y == p2.y) {
if (p1.x > p2.x) {
q = &p1;
p = &p2;
} else if (p1.x == p2.x) {
// Repeat points
assert(false);
}
}
q->edge_list.push_back(this);
}
};
// Triangle-based data structures are know to have better performance than quad-edge structures
// See: J. Shewchuk, "Triangle: Engineering a 2D Quality Mesh Generator and Delaunay Triangulator"
// "Triangulations in CGAL"
class Triangle {
public:
/// Constructor
Triangle(Point& a, Point& b, Point& c);
/// Flags to determine if an edge is a Constrained edge
bool constrained_edge[3];
/// Flags to determine if an edge is a Delauney edge
bool delaunay_edge[3];
Point* GetPoint(const int& index);
Point* PointCW(Point& point);
Point* PointCCW(Point& point);
Point* OppositePoint(Triangle& t, Point& p);
Triangle* GetNeighbor(const int& index);
void MarkNeighbor(Point* p1, Point* p2, Triangle* t);
void MarkNeighbor(Triangle& t);
void MarkConstrainedEdge(const int index);
void MarkConstrainedEdge(Edge& edge);
void MarkConstrainedEdge(Point* p, Point* q);
int Index(const Point* p);
int EdgeIndex(const Point* p1, const Point* p2);
Triangle* NeighborCW(Point& point);
Triangle* NeighborCCW(Point& point);
bool GetConstrainedEdgeCCW(Point& p);
bool GetConstrainedEdgeCW(Point& p);
void SetConstrainedEdgeCCW(Point& p, bool ce);
void SetConstrainedEdgeCW(Point& p, bool ce);
bool GetDelunayEdgeCCW(Point& p);
bool GetDelunayEdgeCW(Point& p);
void SetDelunayEdgeCCW(Point& p, bool e);
void SetDelunayEdgeCW(Point& p, bool e);
bool Contains(Point* p);
bool Contains(const Edge& e);
bool Contains(Point* p, Point* q);
void Legalize(Point& point);
void Legalize(Point& opoint, Point& npoint);
/**
* Clears all references to all other triangles and points
*/
void Clear();
void ClearNeighbor(Triangle *triangle );
void ClearNeighbors();
void ClearDelunayEdges();
inline bool IsInterior();
inline void IsInterior(bool b);
Triangle& NeighborAcross(Point& opoint);
void DebugPrint();
private:
/// Triangle points
Point* points_[3];
/// Neighbor list
Triangle* neighbors_[3];
/// Has this triangle been marked as an interior triangle?
bool interior_;
};
inline bool cmp(const Point* a, const Point* b)
{
if (a->y < b->y) {
return true;
} else if (a->y == b->y) {
// Make sure q is point with greater x value
if (a->x < b->x) {
return true;
}
}
return false;
}
/// Add two points_ component-wise.
inline Point operator +(const Point& a, const Point& b)
{
return Point(a.x + b.x, a.y + b.y);
}
/// Subtract two points_ component-wise.
inline Point operator -(const Point& a, const Point& b)
{
return Point(a.x - b.x, a.y - b.y);
}
/// Multiply point by scalar
inline Point operator *(double s, const Point& a)
{
return Point(s * a.x, s * a.y);
}
inline bool operator ==(const Point& a, const Point& b)
{
return a.x == b.x && a.y == b.y;
}
inline bool operator !=(const Point& a, const Point& b)
{
return !(a.x == b.x) && !(a.y == b.y);
}
/// Peform the dot product on two vectors.
inline double Dot(const Point& a, const Point& b)
{
return a.x * b.x + a.y * b.y;
}
/// Perform the cross product on two vectors. In 2D this produces a scalar.
inline double Cross(const Point& a, const Point& b)
{
return a.x * b.y - a.y * b.x;
}
/// Perform the cross product on a point and a scalar. In 2D this produces
/// a point.
inline Point Cross(const Point& a, double s)
{
return Point(s * a.y, -s * a.x);
}
/// Perform the cross product on a scalar and a point. In 2D this produces
/// a point.
inline Point Cross(const double s, const Point& a)
{
return Point(-s * a.y, s * a.x);
}
inline Point* Triangle::GetPoint(const int& index)
{
return points_[index];
}
inline Triangle* Triangle::GetNeighbor(const int& index)
{
return neighbors_[index];
}
inline bool Triangle::Contains(Point* p)
{
return p == points_[0] || p == points_[1] || p == points_[2];
}
inline bool Triangle::Contains(const Edge& e)
{
return Contains(e.p) && Contains(e.q);
}
inline bool Triangle::Contains(Point* p, Point* q)
{
return Contains(p) && Contains(q);
}
inline bool Triangle::IsInterior()
{
return interior_;
}
inline void Triangle::IsInterior(bool b)
{
interior_ = b;
}
}
#endif

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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef UTILS_H
#define UTILS_H
// Otherwise #defines like M_PI are undeclared under Visual Studio
#define _USE_MATH_DEFINES
#include <exception>
#include <math.h>
namespace p2t {
const double PI_3div4 = 3 * M_PI / 4;
const double PI_div2 = 1.57079632679489661923;
const double EPSILON = 1e-12;
enum Orientation { CW, CCW, COLLINEAR };
/**
* Forumla to calculate signed area<br>
* Positive if CCW<br>
* Negative if CW<br>
* 0 if collinear<br>
* <pre>
* A[P1,P2,P3] = (x1*y2 - y1*x2) + (x2*y3 - y2*x3) + (x3*y1 - y3*x1)
* = (x1-x3)*(y2-y3) - (y1-y3)*(x2-x3)
* </pre>
*/
Orientation Orient2d(Point& pa, Point& pb, Point& pc)
{
double detleft = (pa.x - pc.x) * (pb.y - pc.y);
double detright = (pa.y - pc.y) * (pb.x - pc.x);
double val = detleft - detright;
if (val > -EPSILON && val < EPSILON) {
return COLLINEAR;
} else if (val > 0) {
return CCW;
}
return CW;
}
/*
bool InScanArea(Point& pa, Point& pb, Point& pc, Point& pd)
{
double pdx = pd.x;
double pdy = pd.y;
double adx = pa.x - pdx;
double ady = pa.y - pdy;
double bdx = pb.x - pdx;
double bdy = pb.y - pdy;
double adxbdy = adx * bdy;
double bdxady = bdx * ady;
double oabd = adxbdy - bdxady;
if (oabd <= EPSILON) {
return false;
}
double cdx = pc.x - pdx;
double cdy = pc.y - pdy;
double cdxady = cdx * ady;
double adxcdy = adx * cdy;
double ocad = cdxady - adxcdy;
if (ocad <= EPSILON) {
return false;
}
return true;
}
*/
bool InScanArea(Point& pa, Point& pb, Point& pc, Point& pd)
{
double oadb = (pa.x - pb.x)*(pd.y - pb.y) - (pd.x - pb.x)*(pa.y - pb.y);
if (oadb >= -EPSILON) {
return false;
}
double oadc = (pa.x - pc.x)*(pd.y - pc.y) - (pd.x - pc.x)*(pa.y - pc.y);
if (oadc <= EPSILON) {
return false;
}
return true;
}
}
#endif

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polygon/poly2tri/poly2tri.h Normal file
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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef POLY2TRI_H
#define POLY2TRI_H
#include "common/shapes.h"
#include "sweep/cdt.h"
#endif

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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "advancing_front.h"
namespace p2t {
AdvancingFront::AdvancingFront(Node& head, Node& tail)
{
head_ = &head;
tail_ = &tail;
search_node_ = &head;
}
Node* AdvancingFront::LocateNode(const double& x)
{
Node* node = search_node_;
if (x < node->value) {
while ((node = node->prev) != NULL) {
if (x >= node->value) {
search_node_ = node;
return node;
}
}
} else {
while ((node = node->next) != NULL) {
if (x < node->value) {
search_node_ = node->prev;
return node->prev;
}
}
}
return NULL;
}
Node* AdvancingFront::FindSearchNode(const double& x)
{
(void)x; // suppress compiler warnings "unused parameter 'x'"
// TODO: implement BST index
return search_node_;
}
Node* AdvancingFront::LocatePoint(const Point* point)
{
const double px = point->x;
Node* node = FindSearchNode(px);
const double nx = node->point->x;
if (px == nx) {
if (point != node->point) {
// We might have two nodes with same x value for a short time
if (point == node->prev->point) {
node = node->prev;
} else if (point == node->next->point) {
node = node->next;
} else {
assert(0);
}
}
} else if (px < nx) {
while ((node = node->prev) != NULL) {
if (point == node->point) {
break;
}
}
} else {
while ((node = node->next) != NULL) {
if (point == node->point)
break;
}
}
if(node) search_node_ = node;
return node;
}
AdvancingFront::~AdvancingFront()
{
}
}

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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef ADVANCED_FRONT_H
#define ADVANCED_FRONT_H
#include "../common/shapes.h"
namespace p2t {
struct Node;
// Advancing front node
struct Node {
Point* point;
Triangle* triangle;
Node* next;
Node* prev;
double value;
Node(Point& p) : point(&p), triangle(NULL), next(NULL), prev(NULL), value(p.x)
{
}
Node(Point& p, Triangle& t) : point(&p), triangle(&t), next(NULL), prev(NULL), value(p.x)
{
}
};
// Advancing front
class AdvancingFront {
public:
AdvancingFront(Node& head, Node& tail);
// Destructor
~AdvancingFront();
Node* head();
void set_head(Node* node);
Node* tail();
void set_tail(Node* node);
Node* search();
void set_search(Node* node);
/// Locate insertion point along advancing front
Node* LocateNode(const double& x);
Node* LocatePoint(const Point* point);
private:
Node* head_, *tail_, *search_node_;
Node* FindSearchNode(const double& x);
};
inline Node* AdvancingFront::head()
{
return head_;
}
inline void AdvancingFront::set_head(Node* node)
{
head_ = node;
}
inline Node* AdvancingFront::tail()
{
return tail_;
}
inline void AdvancingFront::set_tail(Node* node)
{
tail_ = node;
}
inline Node* AdvancingFront::search()
{
return search_node_;
}
inline void AdvancingFront::set_search(Node* node)
{
search_node_ = node;
}
}
#endif

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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "cdt.h"
namespace p2t {
CDT::CDT(std::vector<Point*> polyline)
{
sweep_context_ = new SweepContext(polyline);
sweep_ = new Sweep;
}
void CDT::AddHole(std::vector<Point*> polyline)
{
sweep_context_->AddHole(polyline);
}
void CDT::AddPoint(Point* point) {
sweep_context_->AddPoint(point);
}
void CDT::Triangulate()
{
sweep_->Triangulate(*sweep_context_);
}
std::vector<p2t::Triangle*> CDT::GetTriangles()
{
return sweep_context_->GetTriangles();
}
std::list<p2t::Triangle*> CDT::GetMap()
{
return sweep_context_->GetMap();
}
CDT::~CDT()
{
delete sweep_context_;
delete sweep_;
}
}

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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CDT_H
#define CDT_H
#include "advancing_front.h"
#include "sweep_context.h"
#include "sweep.h"
/**
*
* @author Mason Green <mason.green@gmail.com>
*
*/
namespace p2t {
class CDT
{
public:
/**
* Constructor - add polyline with non repeating points
*
* @param polyline
*/
CDT(std::vector<Point*> polyline);
/**
* Destructor - clean up memory
*/
~CDT();
/**
* Add a hole
*
* @param polyline
*/
void AddHole(std::vector<Point*> polyline);
/**
* Add a steiner point
*
* @param point
*/
void AddPoint(Point* point);
/**
* Triangulate - do this AFTER you've added the polyline, holes, and Steiner points
*/
void Triangulate();
/**
* Get CDT triangles
*/
std::vector<Triangle*> GetTriangles();
/**
* Get triangle map
*/
std::list<Triangle*> GetMap();
private:
/**
* Internals
*/
SweepContext* sweep_context_;
Sweep* sweep_;
};
}
#endif

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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdexcept>
#include "sweep.h"
#include "sweep_context.h"
#include "advancing_front.h"
#include "../common/utils.h"
namespace p2t {
// Triangulate simple polygon with holes
void Sweep::Triangulate(SweepContext& tcx)
{
tcx.InitTriangulation();
tcx.CreateAdvancingFront(nodes_);
// Sweep points; build mesh
SweepPoints(tcx);
// Clean up
FinalizationPolygon(tcx);
}
void Sweep::SweepPoints(SweepContext& tcx)
{
for (int i = 1; i < tcx.point_count(); i++) {
Point& point = *tcx.GetPoint(i);
Node* node = &PointEvent(tcx, point);
for (unsigned int i = 0; i < point.edge_list.size(); i++) {
EdgeEvent(tcx, point.edge_list[i], node);
}
}
}
void Sweep::FinalizationPolygon(SweepContext& tcx)
{
// Get an Internal triangle to start with
Triangle* t = tcx.front()->head()->next->triangle;
Point* p = tcx.front()->head()->next->point;
while (!t->GetConstrainedEdgeCW(*p)) {
t = t->NeighborCCW(*p);
}
// Collect interior triangles constrained by edges
tcx.MeshClean(*t);
}
Node& Sweep::PointEvent(SweepContext& tcx, Point& point)
{
Node& node = tcx.LocateNode(point);
Node& new_node = NewFrontTriangle(tcx, point, node);
// Only need to check +epsilon since point never have smaller
// x value than node due to how we fetch nodes from the front
if (point.x <= node.point->x + EPSILON) {
Fill(tcx, node);
}
//tcx.AddNode(new_node);
FillAdvancingFront(tcx, new_node);
return new_node;
}
void Sweep::EdgeEvent(SweepContext& tcx, Edge* edge, Node* node)
{
tcx.edge_event.constrained_edge = edge;
tcx.edge_event.right = (edge->p->x > edge->q->x);
if (IsEdgeSideOfTriangle(*node->triangle, *edge->p, *edge->q)) {
return;
}
// For now we will do all needed filling
// TODO: integrate with flip process might give some better performance
// but for now this avoid the issue with cases that needs both flips and fills
FillEdgeEvent(tcx, edge, node);
EdgeEvent(tcx, *edge->p, *edge->q, node->triangle, *edge->q);
}
void Sweep::EdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle* triangle, Point& point)
{
if (IsEdgeSideOfTriangle(*triangle, ep, eq)) {
return;
}
Point* p1 = triangle->PointCCW(point);
Orientation o1 = Orient2d(eq, *p1, ep);
if (o1 == COLLINEAR) {
if( triangle->Contains(&eq, p1)) {
triangle->MarkConstrainedEdge(&eq, p1 );
// We are modifying the constraint maybe it would be better to
// not change the given constraint and just keep a variable for the new constraint
tcx.edge_event.constrained_edge->q = p1;
triangle = &triangle->NeighborAcross(point);
EdgeEvent( tcx, ep, *p1, triangle, *p1 );
} else {
std::runtime_error("EdgeEvent - collinear points not supported");
assert(0);
}
return;
}
Point* p2 = triangle->PointCW(point);
Orientation o2 = Orient2d(eq, *p2, ep);
if (o2 == COLLINEAR) {
if( triangle->Contains(&eq, p2)) {
triangle->MarkConstrainedEdge(&eq, p2 );
// We are modifying the constraint maybe it would be better to
// not change the given constraint and just keep a variable for the new constraint
tcx.edge_event.constrained_edge->q = p2;
triangle = &triangle->NeighborAcross(point);
EdgeEvent( tcx, ep, *p2, triangle, *p2 );
} else {
std::runtime_error("EdgeEvent - collinear points not supported");
assert(0);
}
return;
}
if (o1 == o2) {
// Need to decide if we are rotating CW or CCW to get to a triangle
// that will cross edge
if (o1 == CW) {
triangle = triangle->NeighborCCW(point);
} else{
triangle = triangle->NeighborCW(point);
}
EdgeEvent(tcx, ep, eq, triangle, point);
} else {
// This triangle crosses constraint so lets flippin start!
FlipEdgeEvent(tcx, ep, eq, triangle, point);
}
}
bool Sweep::IsEdgeSideOfTriangle(Triangle& triangle, Point& ep, Point& eq)
{
int index = triangle.EdgeIndex(&ep, &eq);
if (index != -1) {
triangle.MarkConstrainedEdge(index);
Triangle* t = triangle.GetNeighbor(index);
if (t) {
t->MarkConstrainedEdge(&ep, &eq);
}
return true;
}
return false;
}
Node& Sweep::NewFrontTriangle(SweepContext& tcx, Point& point, Node& node)
{
Triangle* triangle = new Triangle(point, *node.point, *node.next->point);
triangle->MarkNeighbor(*node.triangle);
tcx.AddToMap(triangle);
Node* new_node = new Node(point);
nodes_.push_back(new_node);
new_node->next = node.next;
new_node->prev = &node;
node.next->prev = new_node;
node.next = new_node;
if (!Legalize(tcx, *triangle)) {
tcx.MapTriangleToNodes(*triangle);
}
return *new_node;
}
void Sweep::Fill(SweepContext& tcx, Node& node)
{
Triangle* triangle = new Triangle(*node.prev->point, *node.point, *node.next->point);
// TODO: should copy the constrained_edge value from neighbor triangles
// for now constrained_edge values are copied during the legalize
triangle->MarkNeighbor(*node.prev->triangle);
triangle->MarkNeighbor(*node.triangle);
tcx.AddToMap(triangle);
// Update the advancing front
node.prev->next = node.next;
node.next->prev = node.prev;
// If it was legalized the triangle has already been mapped
if (!Legalize(tcx, *triangle)) {
tcx.MapTriangleToNodes(*triangle);
}
}
void Sweep::FillAdvancingFront(SweepContext& tcx, Node& n)
{
// Fill right holes
Node* node = n.next;
while (node->next) {
// if HoleAngle exceeds 90 degrees then break.
if (LargeHole_DontFill(node)) break;
Fill(tcx, *node);
node = node->next;
}
// Fill left holes
node = n.prev;
while (node->prev) {
// if HoleAngle exceeds 90 degrees then break.
if (LargeHole_DontFill(node)) break;
Fill(tcx, *node);
node = node->prev;
}
// Fill right basins
if (n.next && n.next->next) {
double angle = BasinAngle(n);
if (angle < PI_3div4) {
FillBasin(tcx, n);
}
}
}
// True if HoleAngle exceeds 90 degrees.
bool Sweep::LargeHole_DontFill(Node* node) {
Node* nextNode = node->next;
Node* prevNode = node->prev;
if (!AngleExceeds90Degrees(node->point, nextNode->point, prevNode->point))
return false;
// Check additional points on front.
Node* next2Node = nextNode->next;
// "..Plus.." because only want angles on same side as point being added.
if ((next2Node != NULL) && !AngleExceedsPlus90DegreesOrIsNegative(node->point, next2Node->point, prevNode->point))
return false;
Node* prev2Node = prevNode->prev;
// "..Plus.." because only want angles on same side as point being added.
if ((prev2Node != NULL) && !AngleExceedsPlus90DegreesOrIsNegative(node->point, nextNode->point, prev2Node->point))
return false;
return true;
}
bool Sweep::AngleExceeds90Degrees(Point* origin, Point* pa, Point* pb) {
double angle = Angle(*origin, *pa, *pb);
bool exceeds90Degrees = ((angle > PI_div2) || (angle < -PI_div2));
return exceeds90Degrees;
}
bool Sweep::AngleExceedsPlus90DegreesOrIsNegative(Point* origin, Point* pa, Point* pb) {
double angle = Angle(*origin, *pa, *pb);
bool exceedsPlus90DegreesOrIsNegative = (angle > PI_div2) || (angle < 0);
return exceedsPlus90DegreesOrIsNegative;
}
double Sweep::Angle(Point& origin, Point& pa, Point& pb) {
/* Complex plane
* ab = cosA +i*sinA
* ab = (ax + ay*i)(bx + by*i) = (ax*bx + ay*by) + i(ax*by-ay*bx)
* atan2(y,x) computes the principal value of the argument function
* applied to the complex number x+iy
* Where x = ax*bx + ay*by
* y = ax*by - ay*bx
*/
double px = origin.x;
double py = origin.y;
double ax = pa.x- px;
double ay = pa.y - py;
double bx = pb.x - px;
double by = pb.y - py;
double x = ax * by - ay * bx;
double y = ax * bx + ay * by;
double angle = atan2(x, y);
return angle;
}
double Sweep::BasinAngle(Node& node)
{
double ax = node.point->x - node.next->next->point->x;
double ay = node.point->y - node.next->next->point->y;
return atan2(ay, ax);
}
double Sweep::HoleAngle(Node& node)
{
/* Complex plane
* ab = cosA +i*sinA
* ab = (ax + ay*i)(bx + by*i) = (ax*bx + ay*by) + i(ax*by-ay*bx)
* atan2(y,x) computes the principal value of the argument function
* applied to the complex number x+iy
* Where x = ax*bx + ay*by
* y = ax*by - ay*bx
*/
double ax = node.next->point->x - node.point->x;
double ay = node.next->point->y - node.point->y;
double bx = node.prev->point->x - node.point->x;
double by = node.prev->point->y - node.point->y;
return atan2(ax * by - ay * bx, ax * bx + ay * by);
}
bool Sweep::Legalize(SweepContext& tcx, Triangle& t)
{
// To legalize a triangle we start by finding if any of the three edges
// violate the Delaunay condition
for (int i = 0; i < 3; i++) {
if (t.delaunay_edge[i])
continue;
Triangle* ot = t.GetNeighbor(i);
if (ot) {
Point* p = t.GetPoint(i);
Point* op = ot->OppositePoint(t, *p);
int oi = ot->Index(op);
// If this is a Constrained Edge or a Delaunay Edge(only during recursive legalization)
// then we should not try to legalize
if (ot->constrained_edge[oi] || ot->delaunay_edge[oi]) {
t.constrained_edge[i] = ot->constrained_edge[oi];
continue;
}
bool inside = Incircle(*p, *t.PointCCW(*p), *t.PointCW(*p), *op);
if (inside) {
// Lets mark this shared edge as Delaunay
t.delaunay_edge[i] = true;
ot->delaunay_edge[oi] = true;
// Lets rotate shared edge one vertex CW to legalize it
RotateTrianglePair(t, *p, *ot, *op);
// We now got one valid Delaunay Edge shared by two triangles
// This gives us 4 new edges to check for Delaunay
// Make sure that triangle to node mapping is done only one time for a specific triangle
bool not_legalized = !Legalize(tcx, t);
if (not_legalized) {
tcx.MapTriangleToNodes(t);
}
not_legalized = !Legalize(tcx, *ot);
if (not_legalized)
tcx.MapTriangleToNodes(*ot);
// Reset the Delaunay edges, since they only are valid Delaunay edges
// until we add a new triangle or point.
// XXX: need to think about this. Can these edges be tried after we
// return to previous recursive level?
t.delaunay_edge[i] = false;
ot->delaunay_edge[oi] = false;
// If triangle have been legalized no need to check the other edges since
// the recursive legalization will handles those so we can end here.
return true;
}
}
}
return false;
}
bool Sweep::Incircle(Point& pa, Point& pb, Point& pc, Point& pd)
{
double adx = pa.x - pd.x;
double ady = pa.y - pd.y;
double bdx = pb.x - pd.x;
double bdy = pb.y - pd.y;
double adxbdy = adx * bdy;
double bdxady = bdx * ady;
double oabd = adxbdy - bdxady;
if (oabd <= 0)
return false;
double cdx = pc.x - pd.x;
double cdy = pc.y - pd.y;
double cdxady = cdx * ady;
double adxcdy = adx * cdy;
double ocad = cdxady - adxcdy;
if (ocad <= 0)
return false;
double bdxcdy = bdx * cdy;
double cdxbdy = cdx * bdy;
double alift = adx * adx + ady * ady;
double blift = bdx * bdx + bdy * bdy;
double clift = cdx * cdx + cdy * cdy;
double det = alift * (bdxcdy - cdxbdy) + blift * ocad + clift * oabd;
return det > 0;
}
void Sweep::RotateTrianglePair(Triangle& t, Point& p, Triangle& ot, Point& op)
{
Triangle* n1, *n2, *n3, *n4;
n1 = t.NeighborCCW(p);
n2 = t.NeighborCW(p);
n3 = ot.NeighborCCW(op);
n4 = ot.NeighborCW(op);
bool ce1, ce2, ce3, ce4;
ce1 = t.GetConstrainedEdgeCCW(p);
ce2 = t.GetConstrainedEdgeCW(p);
ce3 = ot.GetConstrainedEdgeCCW(op);
ce4 = ot.GetConstrainedEdgeCW(op);
bool de1, de2, de3, de4;
de1 = t.GetDelunayEdgeCCW(p);
de2 = t.GetDelunayEdgeCW(p);
de3 = ot.GetDelunayEdgeCCW(op);
de4 = ot.GetDelunayEdgeCW(op);
t.Legalize(p, op);
ot.Legalize(op, p);
// Remap delaunay_edge
ot.SetDelunayEdgeCCW(p, de1);
t.SetDelunayEdgeCW(p, de2);
t.SetDelunayEdgeCCW(op, de3);
ot.SetDelunayEdgeCW(op, de4);
// Remap constrained_edge
ot.SetConstrainedEdgeCCW(p, ce1);
t.SetConstrainedEdgeCW(p, ce2);
t.SetConstrainedEdgeCCW(op, ce3);
ot.SetConstrainedEdgeCW(op, ce4);
// Remap neighbors
// XXX: might optimize the markNeighbor by keeping track of
// what side should be assigned to what neighbor after the
// rotation. Now mark neighbor does lots of testing to find
// the right side.
t.ClearNeighbors();
ot.ClearNeighbors();
if (n1) ot.MarkNeighbor(*n1);
if (n2) t.MarkNeighbor(*n2);
if (n3) t.MarkNeighbor(*n3);
if (n4) ot.MarkNeighbor(*n4);
t.MarkNeighbor(ot);
}
void Sweep::FillBasin(SweepContext& tcx, Node& node)
{
if (Orient2d(*node.point, *node.next->point, *node.next->next->point) == CCW) {
tcx.basin.left_node = node.next->next;
} else {
tcx.basin.left_node = node.next;
}
// Find the bottom and right node
tcx.basin.bottom_node = tcx.basin.left_node;
while (tcx.basin.bottom_node->next
&& tcx.basin.bottom_node->point->y >= tcx.basin.bottom_node->next->point->y) {
tcx.basin.bottom_node = tcx.basin.bottom_node->next;
}
if (tcx.basin.bottom_node == tcx.basin.left_node) {
// No valid basin
return;
}
tcx.basin.right_node = tcx.basin.bottom_node;
while (tcx.basin.right_node->next
&& tcx.basin.right_node->point->y < tcx.basin.right_node->next->point->y) {
tcx.basin.right_node = tcx.basin.right_node->next;
}
if (tcx.basin.right_node == tcx.basin.bottom_node) {
// No valid basins
return;
}
tcx.basin.width = tcx.basin.right_node->point->x - tcx.basin.left_node->point->x;
tcx.basin.left_highest = tcx.basin.left_node->point->y > tcx.basin.right_node->point->y;
FillBasinReq(tcx, tcx.basin.bottom_node);
}
void Sweep::FillBasinReq(SweepContext& tcx, Node* node)
{
// if shallow stop filling
if (IsShallow(tcx, *node)) {
return;
}
Fill(tcx, *node);
if (node->prev == tcx.basin.left_node && node->next == tcx.basin.right_node) {
return;
} else if (node->prev == tcx.basin.left_node) {
Orientation o = Orient2d(*node->point, *node->next->point, *node->next->next->point);
if (o == CW) {
return;
}
node = node->next;
} else if (node->next == tcx.basin.right_node) {
Orientation o = Orient2d(*node->point, *node->prev->point, *node->prev->prev->point);
if (o == CCW) {
return;
}
node = node->prev;
} else {
// Continue with the neighbor node with lowest Y value
if (node->prev->point->y < node->next->point->y) {
node = node->prev;
} else {
node = node->next;
}
}
FillBasinReq(tcx, node);
}
bool Sweep::IsShallow(SweepContext& tcx, Node& node)
{
double height;
if (tcx.basin.left_highest) {
height = tcx.basin.left_node->point->y - node.point->y;
} else {
height = tcx.basin.right_node->point->y - node.point->y;
}
// if shallow stop filling
if (tcx.basin.width > height) {
return true;
}
return false;
}
void Sweep::FillEdgeEvent(SweepContext& tcx, Edge* edge, Node* node)
{
if (tcx.edge_event.right) {
FillRightAboveEdgeEvent(tcx, edge, node);
} else {
FillLeftAboveEdgeEvent(tcx, edge, node);
}
}
void Sweep::FillRightAboveEdgeEvent(SweepContext& tcx, Edge* edge, Node* node)
{
while (node->next->point->x < edge->p->x) {
// Check if next node is below the edge
if (Orient2d(*edge->q, *node->next->point, *edge->p) == CCW) {
FillRightBelowEdgeEvent(tcx, edge, *node);
} else {
node = node->next;
}
}
}
void Sweep::FillRightBelowEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
{
if (node.point->x < edge->p->x) {
if (Orient2d(*node.point, *node.next->point, *node.next->next->point) == CCW) {
// Concave
FillRightConcaveEdgeEvent(tcx, edge, node);
} else{
// Convex
FillRightConvexEdgeEvent(tcx, edge, node);
// Retry this one
FillRightBelowEdgeEvent(tcx, edge, node);
}
}
}
void Sweep::FillRightConcaveEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
{
Fill(tcx, *node.next);
if (node.next->point != edge->p) {
// Next above or below edge?
if (Orient2d(*edge->q, *node.next->point, *edge->p) == CCW) {
// Below
if (Orient2d(*node.point, *node.next->point, *node.next->next->point) == CCW) {
// Next is concave
FillRightConcaveEdgeEvent(tcx, edge, node);
} else {
// Next is convex
}
}
}
}
void Sweep::FillRightConvexEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
{
// Next concave or convex?
if (Orient2d(*node.next->point, *node.next->next->point, *node.next->next->next->point) == CCW) {
// Concave
FillRightConcaveEdgeEvent(tcx, edge, *node.next);
} else{
// Convex
// Next above or below edge?
if (Orient2d(*edge->q, *node.next->next->point, *edge->p) == CCW) {
// Below
FillRightConvexEdgeEvent(tcx, edge, *node.next);
} else{
// Above
}
}
}
void Sweep::FillLeftAboveEdgeEvent(SweepContext& tcx, Edge* edge, Node* node)
{
while (node->prev->point->x > edge->p->x) {
// Check if next node is below the edge
if (Orient2d(*edge->q, *node->prev->point, *edge->p) == CW) {
FillLeftBelowEdgeEvent(tcx, edge, *node);
} else {
node = node->prev;
}
}
}
void Sweep::FillLeftBelowEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
{
if (node.point->x > edge->p->x) {
if (Orient2d(*node.point, *node.prev->point, *node.prev->prev->point) == CW) {
// Concave
FillLeftConcaveEdgeEvent(tcx, edge, node);
} else {
// Convex
FillLeftConvexEdgeEvent(tcx, edge, node);
// Retry this one
FillLeftBelowEdgeEvent(tcx, edge, node);
}
}
}
void Sweep::FillLeftConvexEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
{
// Next concave or convex?
if (Orient2d(*node.prev->point, *node.prev->prev->point, *node.prev->prev->prev->point) == CW) {
// Concave
FillLeftConcaveEdgeEvent(tcx, edge, *node.prev);
} else{
// Convex
// Next above or below edge?
if (Orient2d(*edge->q, *node.prev->prev->point, *edge->p) == CW) {
// Below
FillLeftConvexEdgeEvent(tcx, edge, *node.prev);
} else{
// Above
}
}
}
void Sweep::FillLeftConcaveEdgeEvent(SweepContext& tcx, Edge* edge, Node& node)
{
Fill(tcx, *node.prev);
if (node.prev->point != edge->p) {
// Next above or below edge?
if (Orient2d(*edge->q, *node.prev->point, *edge->p) == CW) {
// Below
if (Orient2d(*node.point, *node.prev->point, *node.prev->prev->point) == CW) {
// Next is concave
FillLeftConcaveEdgeEvent(tcx, edge, node);
} else{
// Next is convex
}
}
}
}
void Sweep::FlipEdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle* t, Point& p)
{
Triangle& ot = t->NeighborAcross(p);
Point& op = *ot.OppositePoint(*t, p);
if (&ot == NULL) {
// If we want to integrate the fillEdgeEvent do it here
// With current implementation we should never get here
//throw new RuntimeException( "[BUG:FIXME] FLIP failed due to missing triangle");
assert(0);
}
if (InScanArea(p, *t->PointCCW(p), *t->PointCW(p), op)) {
// Lets rotate shared edge one vertex CW
RotateTrianglePair(*t, p, ot, op);
tcx.MapTriangleToNodes(*t);
tcx.MapTriangleToNodes(ot);
if (p == eq && op == ep) {
if (eq == *tcx.edge_event.constrained_edge->q && ep == *tcx.edge_event.constrained_edge->p) {
t->MarkConstrainedEdge(&ep, &eq);
ot.MarkConstrainedEdge(&ep, &eq);
Legalize(tcx, *t);
Legalize(tcx, ot);
} else {
// XXX: I think one of the triangles should be legalized here?
}
} else {
Orientation o = Orient2d(eq, op, ep);
t = &NextFlipTriangle(tcx, (int)o, *t, ot, p, op);
FlipEdgeEvent(tcx, ep, eq, t, p);
}
} else {
Point& newP = NextFlipPoint(ep, eq, ot, op);
FlipScanEdgeEvent(tcx, ep, eq, *t, ot, newP);
EdgeEvent(tcx, ep, eq, t, p);
}
}
Triangle& Sweep::NextFlipTriangle(SweepContext& tcx, int o, Triangle& t, Triangle& ot, Point& p, Point& op)
{
if (o == CCW) {
// ot is not crossing edge after flip
int edge_index = ot.EdgeIndex(&p, &op);
ot.delaunay_edge[edge_index] = true;
Legalize(tcx, ot);
ot.ClearDelunayEdges();
return t;
}
// t is not crossing edge after flip
int edge_index = t.EdgeIndex(&p, &op);
t.delaunay_edge[edge_index] = true;
Legalize(tcx, t);
t.ClearDelunayEdges();
return ot;
}
Point& Sweep::NextFlipPoint(Point& ep, Point& eq, Triangle& ot, Point& op)
{
Orientation o2d = Orient2d(eq, op, ep);
if (o2d == CW) {
// Right
return *ot.PointCCW(op);
} else if (o2d == CCW) {
// Left
return *ot.PointCW(op);
} else{
//throw new RuntimeException("[Unsupported] Opposing point on constrained edge");
assert(0);
}
}
void Sweep::FlipScanEdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle& flip_triangle,
Triangle& t, Point& p)
{
Triangle& ot = t.NeighborAcross(p);
Point& op = *ot.OppositePoint(t, p);
if (&t.NeighborAcross(p) == NULL) {
// If we want to integrate the fillEdgeEvent do it here
// With current implementation we should never get here
//throw new RuntimeException( "[BUG:FIXME] FLIP failed due to missing triangle");
assert(0);
}
if (InScanArea(eq, *flip_triangle.PointCCW(eq), *flip_triangle.PointCW(eq), op)) {
// flip with new edge op->eq
FlipEdgeEvent(tcx, eq, op, &ot, op);
// TODO: Actually I just figured out that it should be possible to
// improve this by getting the next ot and op before the the above
// flip and continue the flipScanEdgeEvent here
// set new ot and op here and loop back to inScanArea test
// also need to set a new flip_triangle first
// Turns out at first glance that this is somewhat complicated
// so it will have to wait.
} else{
Point& newP = NextFlipPoint(ep, eq, ot, op);
FlipScanEdgeEvent(tcx, ep, eq, flip_triangle, ot, newP);
}
}
Sweep::~Sweep() {
// Clean up memory
for(int i = 0; i < nodes_.size(); i++) {
delete nodes_[i];
}
}
}

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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* Sweep-line, Constrained Delauney Triangulation (CDT) See: Domiter, V. and
* Zalik, B.(2008)'Sweep-line algorithm for constrained Delaunay triangulation',
* International Journal of Geographical Information Science
*
* "FlipScan" Constrained Edge Algorithm invented by Thomas Åhlén, thahlen@gmail.com
*/
#ifndef SWEEP_H
#define SWEEP_H
#include <vector>
namespace p2t {
class SweepContext;
struct Node;
struct Point;
struct Edge;
class Triangle;
class Sweep
{
public:
/**
* Triangulate
*
* @param tcx
*/
void Triangulate(SweepContext& tcx);
/**
* Destructor - clean up memory
*/
~Sweep();
private:
/**
* Start sweeping the Y-sorted point set from bottom to top
*
* @param tcx
*/
void SweepPoints(SweepContext& tcx);
/**
* Find closes node to the left of the new point and
* create a new triangle. If needed new holes and basins
* will be filled to.
*
* @param tcx
* @param point
* @return
*/
Node& PointEvent(SweepContext& tcx, Point& point);
/**
*
*
* @param tcx
* @param edge
* @param node
*/
void EdgeEvent(SweepContext& tcx, Edge* edge, Node* node);
void EdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle* triangle, Point& point);
/**
* Creates a new front triangle and legalize it
*
* @param tcx
* @param point
* @param node
* @return
*/
Node& NewFrontTriangle(SweepContext& tcx, Point& point, Node& node);
/**
* Adds a triangle to the advancing front to fill a hole.
* @param tcx
* @param node - middle node, that is the bottom of the hole
*/
void Fill(SweepContext& tcx, Node& node);
/**
* Returns true if triangle was legalized
*/
bool Legalize(SweepContext& tcx, Triangle& t);
/**
* <b>Requirement</b>:<br>
* 1. a,b and c form a triangle.<br>
* 2. a and d is know to be on opposite side of bc<br>
* <pre>
* a
* +
* / \
* / \
* b/ \c
* +-------+
* / d \
* / \
* </pre>
* <b>Fact</b>: d has to be in area B to have a chance to be inside the circle formed by
* a,b and c<br>
* d is outside B if orient2d(a,b,d) or orient2d(c,a,d) is CW<br>
* This preknowledge gives us a way to optimize the incircle test
* @param a - triangle point, opposite d
* @param b - triangle point
* @param c - triangle point
* @param d - point opposite a
* @return true if d is inside circle, false if on circle edge
*/
bool Incircle(Point& pa, Point& pb, Point& pc, Point& pd);
/**
* Rotates a triangle pair one vertex CW
*<pre>
* n2 n2
* P +-----+ P +-----+
* | t /| |\ t |
* | / | | \ |
* n1| / |n3 n1| \ |n3
* | / | after CW | \ |
* |/ oT | | oT \|
* +-----+ oP +-----+
* n4 n4
* </pre>
*/
void RotateTrianglePair(Triangle& t, Point& p, Triangle& ot, Point& op);
/**
* Fills holes in the Advancing Front
*
*
* @param tcx
* @param n
*/
void FillAdvancingFront(SweepContext& tcx, Node& n);
// Decision-making about when to Fill hole.
// Contributed by ToolmakerSteve2
bool LargeHole_DontFill(Node* node);
bool AngleExceeds90Degrees(Point* origin, Point* pa, Point* pb);
bool AngleExceedsPlus90DegreesOrIsNegative(Point* origin, Point* pa, Point* pb);
double Angle(Point& origin, Point& pa, Point& pb);
/**
*
* @param node - middle node
* @return the angle between 3 front nodes
*/
double HoleAngle(Node& node);
/**
* The basin angle is decided against the horizontal line [1,0]
*/
double BasinAngle(Node& node);
/**
* Fills a basin that has formed on the Advancing Front to the right
* of given node.<br>
* First we decide a left,bottom and right node that forms the
* boundaries of the basin. Then we do a reqursive fill.
*
* @param tcx
* @param node - starting node, this or next node will be left node
*/
void FillBasin(SweepContext& tcx, Node& node);
/**
* Recursive algorithm to fill a Basin with triangles
*
* @param tcx
* @param node - bottom_node
* @param cnt - counter used to alternate on even and odd numbers
*/
void FillBasinReq(SweepContext& tcx, Node* node);
bool IsShallow(SweepContext& tcx, Node& node);
bool IsEdgeSideOfTriangle(Triangle& triangle, Point& ep, Point& eq);
void FillEdgeEvent(SweepContext& tcx, Edge* edge, Node* node);
void FillRightAboveEdgeEvent(SweepContext& tcx, Edge* edge, Node* node);
void FillRightBelowEdgeEvent(SweepContext& tcx, Edge* edge, Node& node);
void FillRightConcaveEdgeEvent(SweepContext& tcx, Edge* edge, Node& node);
void FillRightConvexEdgeEvent(SweepContext& tcx, Edge* edge, Node& node);
void FillLeftAboveEdgeEvent(SweepContext& tcx, Edge* edge, Node* node);
void FillLeftBelowEdgeEvent(SweepContext& tcx, Edge* edge, Node& node);
void FillLeftConcaveEdgeEvent(SweepContext& tcx, Edge* edge, Node& node);
void FillLeftConvexEdgeEvent(SweepContext& tcx, Edge* edge, Node& node);
void FlipEdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle* t, Point& p);
/**
* After a flip we have two triangles and know that only one will still be
* intersecting the edge. So decide which to contiune with and legalize the other
*
* @param tcx
* @param o - should be the result of an orient2d( eq, op, ep )
* @param t - triangle 1
* @param ot - triangle 2
* @param p - a point shared by both triangles
* @param op - another point shared by both triangles
* @return returns the triangle still intersecting the edge
*/
Triangle& NextFlipTriangle(SweepContext& tcx, int o, Triangle& t, Triangle& ot, Point& p, Point& op);
/**
* When we need to traverse from one triangle to the next we need
* the point in current triangle that is the opposite point to the next
* triangle.
*
* @param ep
* @param eq
* @param ot
* @param op
* @return
*/
Point& NextFlipPoint(Point& ep, Point& eq, Triangle& ot, Point& op);
/**
* Scan part of the FlipScan algorithm<br>
* When a triangle pair isn't flippable we will scan for the next
* point that is inside the flip triangle scan area. When found
* we generate a new flipEdgeEvent
*
* @param tcx
* @param ep - last point on the edge we are traversing
* @param eq - first point on the edge we are traversing
* @param flipTriangle - the current triangle sharing the point eq with edge
* @param t
* @param p
*/
void FlipScanEdgeEvent(SweepContext& tcx, Point& ep, Point& eq, Triangle& flip_triangle, Triangle& t, Point& p);
void FinalizationPolygon(SweepContext& tcx);
std::vector<Node*> nodes_;
};
}
#endif

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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "sweep_context.h"
#include <algorithm>
#include "advancing_front.h"
namespace p2t {
SweepContext::SweepContext(std::vector<Point*> polyline) :
front_(0),
head_(0),
tail_(0),
af_head_(0),
af_middle_(0),
af_tail_(0)
{
basin = Basin();
edge_event = EdgeEvent();
points_ = polyline;
InitEdges(points_);
}
void SweepContext::AddHole(std::vector<Point*> polyline)
{
InitEdges(polyline);
for(unsigned int i = 0; i < polyline.size(); i++) {
points_.push_back(polyline[i]);
}
}
void SweepContext::AddPoint(Point* point) {
points_.push_back(point);
}
std::vector<Triangle*> SweepContext::GetTriangles()
{
return triangles_;
}
std::list<Triangle*> SweepContext::GetMap()
{
return map_;
}
void SweepContext::InitTriangulation()
{
double xmax(points_[0]->x), xmin(points_[0]->x);
double ymax(points_[0]->y), ymin(points_[0]->y);
// Calculate bounds.
for (unsigned int i = 0; i < points_.size(); i++) {
Point& p = *points_[i];
if (p.x > xmax)
xmax = p.x;
if (p.x < xmin)
xmin = p.x;
if (p.y > ymax)
ymax = p.y;
if (p.y < ymin)
ymin = p.y;
}
double dx = kAlpha * (xmax - xmin);
double dy = kAlpha * (ymax - ymin);
head_ = new Point(xmax + dx, ymin - dy);
tail_ = new Point(xmin - dx, ymin - dy);
// Sort points along y-axis
std::sort(points_.begin(), points_.end(), cmp);
}
void SweepContext::InitEdges(std::vector<Point*> polyline)
{
int num_points = polyline.size();
for (int i = 0; i < num_points; i++) {
int j = i < num_points - 1 ? i + 1 : 0;
edge_list.push_back(new Edge(*polyline[i], *polyline[j]));
}
}
Point* SweepContext::GetPoint(const int& index)
{
return points_[index];
}
void SweepContext::AddToMap(Triangle* triangle)
{
map_.push_back(triangle);
}
Node& SweepContext::LocateNode(Point& point)
{
// TODO implement search tree
return *front_->LocateNode(point.x);
}
void SweepContext::CreateAdvancingFront(std::vector<Node*> nodes)
{
(void) nodes;
// Initial triangle
Triangle* triangle = new Triangle(*points_[0], *tail_, *head_);
map_.push_back(triangle);
af_head_ = new Node(*triangle->GetPoint(1), *triangle);
af_middle_ = new Node(*triangle->GetPoint(0), *triangle);
af_tail_ = new Node(*triangle->GetPoint(2));
front_ = new AdvancingFront(*af_head_, *af_tail_);
// TODO: More intuitive if head is middles next and not previous?
// so swap head and tail
af_head_->next = af_middle_;
af_middle_->next = af_tail_;
af_middle_->prev = af_head_;
af_tail_->prev = af_middle_;
}
void SweepContext::RemoveNode(Node* node)
{
delete node;
}
void SweepContext::MapTriangleToNodes(Triangle& t)
{
for (int i = 0; i < 3; i++) {
if (!t.GetNeighbor(i)) {
Node* n = front_->LocatePoint(t.PointCW(*t.GetPoint(i)));
if (n)
n->triangle = &t;
}
}
}
void SweepContext::RemoveFromMap(Triangle* triangle)
{
map_.remove(triangle);
}
void SweepContext::MeshClean(Triangle& triangle)
{
std::vector<Triangle *> triangles;
triangles.push_back(&triangle);
while(!triangles.empty()){
Triangle *t = triangles.back();
triangles.pop_back();
if (t != NULL && !t->IsInterior()) {
t->IsInterior(true);
triangles_.push_back(t);
for (int i = 0; i < 3; i++) {
if (!t->constrained_edge[i])
triangles.push_back(t->GetNeighbor(i));
}
}
}
}
SweepContext::~SweepContext()
{
// Clean up memory
delete head_;
delete tail_;
delete front_;
delete af_head_;
delete af_middle_;
delete af_tail_;
typedef std::list<Triangle*> type_list;
for(type_list::iterator iter = map_.begin(); iter != map_.end(); ++iter) {
Triangle* ptr = *iter;
delete ptr;
}
for(unsigned int i = 0; i < edge_list.size(); i++) {
delete edge_list[i];
}
}
}

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polygon/poly2tri/sweep/sweep_context.h Normal file
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/*
* Poly2Tri Copyright (c) 2009-2010, Poly2Tri Contributors
* http://code.google.com/p/poly2tri/
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* * Neither the name of Poly2Tri nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef SWEEP_CONTEXT_H
#define SWEEP_CONTEXT_H
#include <list>
#include <vector>
#include <cstddef>
namespace p2t {
// Inital triangle factor, seed triangle will extend 30% of
// PointSet width to both left and right.
const double kAlpha = 0.3;
struct Point;
class Triangle;
struct Node;
struct Edge;
class AdvancingFront;
class SweepContext {
public:
/// Constructor
SweepContext(std::vector<Point*> polyline);
/// Destructor
~SweepContext();
void set_head(Point* p1);
Point* head();
void set_tail(Point* p1);
Point* tail();
int point_count();
Node& LocateNode(Point& point);
void RemoveNode(Node* node);
void CreateAdvancingFront(std::vector<Node*> nodes);
/// Try to map a node to all sides of this triangle that don't have a neighbor
void MapTriangleToNodes(Triangle& t);
void AddToMap(Triangle* triangle);
Point* GetPoint(const int& index);
Point* GetPoints();
void RemoveFromMap(Triangle* triangle);
void AddHole(std::vector<Point*> polyline);
void AddPoint(Point* point);
AdvancingFront* front();
void MeshClean(Triangle& triangle);
std::vector<Triangle*> GetTriangles();
std::list<Triangle*> GetMap();
std::vector<Edge*> edge_list;
struct Basin {
Node* left_node;
Node* bottom_node;
Node* right_node;
double width;
bool left_highest;
Basin() : left_node(NULL), bottom_node(NULL), right_node(NULL), width(0.0), left_highest(false)
{
}
void Clear()
{
left_node = NULL;
bottom_node = NULL;
right_node = NULL;
width = 0.0;
left_highest = false;
}
};
struct EdgeEvent {
Edge* constrained_edge;
bool right;
EdgeEvent() : constrained_edge(NULL), right(false)
{
}
};
Basin basin;
EdgeEvent edge_event;
private:
friend class Sweep;
std::vector<Triangle*> triangles_;
std::list<Triangle*> map_;
std::vector<Point*> points_;
// Advancing front
AdvancingFront* front_;
// head point used with advancing front
Point* head_;
// tail point used with advancing front
Point* tail_;
Node *af_head_, *af_middle_, *af_tail_;
void InitTriangulation();
void InitEdges(std::vector<Point*> polyline);
};
inline AdvancingFront* SweepContext::front()
{
return front_;
}
inline int SweepContext::point_count()
{
return points_.size();
}
inline void SweepContext::set_head(Point* p1)
{
head_ = p1;
}
inline Point* SweepContext::head()
{
return head_;
}
inline void SweepContext::set_tail(Point* p1)
{
tail_ = p1;
}
inline Point* SweepContext::tail()
{
return tail_;
}
}
#endif