kicad/polygon/poly2tri/common/shapes.h

326 lines
7.3 KiB
C++

/*
* 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;
int id;
/// Default constructor does nothing (for performance).
Point()
{
x = 0.0;
y = 0.0;
id = 0;
}
/// The edges this point constitutes an upper ending point
std::vector<Edge*> edge_list;
/// Construct using coordinates.
Point(double ax, double ay, int aid = 0) : x(ax), y(ay), id(aid) {}
/// 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