1 // segment.h (A line segment)
2 //
3 // The WorldForge Project
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5 //
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23
24 // Author: Ron Steinke
25
26 #ifndef WFMATH_SEGMENT_H
27 #define WFMATH_SEGMENT_H
28
29 #include <wfmath/point.h>
30 #include <wfmath/intersect_decls.h>
31
32 namespace WFMath {
33
34 template<int dim>
35 std::ostream& operator<<(std::ostream& os, const Segment<dim>& s);
36 template<int dim>
37 std::istream& operator>>(std::istream& is, Segment<dim>& s);
38
39 /// A line segment embedded in dim dimensions
40 /**
41 * This class implements the full shape interface, as described in
42 * the fake class Shape.
43 **/
44 template<int dim = 3>
45 class Segment
46 {
47 public:
48 /// construct an uninitialized segment
Segment()49 Segment() :m_p1(), m_p2() {}
50 /// construct a segment with endpoints p1 and p2
Segment(const Point<dim> & p1,const Point<dim> & p2)51 Segment(const Point<dim>& p1, const Point<dim>& p2) : m_p1(p1), m_p2(p2) {}
52 /// construct a copy of a segment
Segment(const Segment & s)53 Segment(const Segment& s) : m_p1(s.m_p1), m_p2(s.m_p2) {}
54
~Segment()55 ~Segment() {}
56
57 friend std::ostream& operator<< <dim>(std::ostream& os, const Segment& s);
58 friend std::istream& operator>> <dim>(std::istream& is, Segment& s);
59
60 Segment& operator=(const Segment& s)
61 {m_p1 = s.m_p1; m_p2 = s.m_p2; return *this;}
62
63 bool isEqualTo(const Segment& s, CoordType epsilon = numeric_constants<CoordType>::epsilon()) const;
64
65 bool operator==(const Segment& b) const {return isEqualTo(b);}
66 bool operator!=(const Segment& b) const {return !isEqualTo(b);}
67
isValid()68 bool isValid() const {return m_p1.isValid() && m_p2.isValid();}
69
70 // Descriptive characteristics
71
numCorners()72 size_t numCorners() const {return 2;}
getCorner(size_t i)73 Point<dim> getCorner(size_t i) const {return i ? m_p2 : m_p1;}
getCenter()74 Point<dim> getCenter() const {return Midpoint(m_p1, m_p2);}
75
76 /// get one end of the segment
endpoint(const int i)77 const Point<dim>& endpoint(const int i) const {return i ? m_p2 : m_p1;}
78 /// get one end of the segment
endpoint(const int i)79 Point<dim>& endpoint(const int i) {return i ? m_p2 : m_p1;}
80
81 // Movement functions
82
shift(const Vector<dim> & v)83 Segment& shift(const Vector<dim>& v)
84 {m_p1 += v; m_p2 += v; return *this;}
85 Segment& moveCornerTo(const Point<dim>& p, size_t corner);
moveCenterTo(const Point<dim> & p)86 Segment& moveCenterTo(const Point<dim>& p)
87 {return shift(p - getCenter());}
88
89 Segment& rotateCorner(const RotMatrix<dim>& m, size_t corner);
rotateCenter(const RotMatrix<dim> & m)90 Segment& rotateCenter(const RotMatrix<dim>& m)
91 {rotatePoint(m, getCenter()); return *this;}
rotatePoint(const RotMatrix<dim> & m,const Point<dim> & p)92 Segment<dim>& rotatePoint(const RotMatrix<dim>& m, const Point<dim>& p)
93 {m_p1.rotate(m, p); m_p2.rotate(m, p); return *this;}
94
95 // 3D rotation functions
96 Segment& rotateCorner(const Quaternion& q, size_t corner);
97 Segment& rotateCenter(const Quaternion& q);
98 Segment& rotatePoint(const Quaternion& q, const Point<dim>& p);
99
100 // Intersection functions
101
boundingBox()102 AxisBox<dim> boundingBox() const {return AxisBox<dim>(m_p1, m_p2);}
boundingSphere()103 Ball<dim> boundingSphere() const
104 {return Ball<dim>(getCenter(), Distance(m_p1, m_p2) / 2);}
boundingSphereSloppy()105 Ball<dim> boundingSphereSloppy() const
106 {return Ball<dim>(getCenter(), SloppyDistance(m_p1, m_p2) / 2);}
107
108 Segment toParentCoords(const Point<dim>& origin,
109 const RotMatrix<dim>& rotation = RotMatrix<dim>().identity()) const
110 {return Segment(m_p1.toParentCoords(origin, rotation),
111 m_p2.toParentCoords(origin, rotation));}
toParentCoords(const AxisBox<dim> & coords)112 Segment toParentCoords(const AxisBox<dim>& coords) const
113 {return Segment(m_p1.toParentCoords(coords), m_p2.toParentCoords(coords));}
toParentCoords(const RotBox<dim> & coords)114 Segment toParentCoords(const RotBox<dim>& coords) const
115 {return Segment(m_p1.toParentCoords(coords), m_p2.toParentCoords(coords));}
116
117 // toLocal is just like toParent, expect we reverse the order of
118 // translation and rotation and use the opposite sense of the rotation
119 // matrix
120
121 Segment toLocalCoords(const Point<dim>& origin,
122 const RotMatrix<dim>& rotation = RotMatrix<dim>().identity()) const
123 {return Segment(m_p1.toLocalCoords(origin, rotation),
124 m_p2.toLocalCoords(origin, rotation));}
toLocalCoords(const AxisBox<dim> & coords)125 Segment toLocalCoords(const AxisBox<dim>& coords) const
126 {return Segment(m_p1.toLocalCoords(coords), m_p2.toLocalCoords(coords));}
toLocalCoords(const RotBox<dim> & coords)127 Segment toLocalCoords(const RotBox<dim>& coords) const
128 {return Segment(m_p1.toLocalCoords(coords), m_p2.toLocalCoords(coords));}
129
130 // 3D only
131 Segment toParentCoords(const Point<dim>& origin,
132 const Quaternion& rotation) const;
133 Segment toLocalCoords(const Point<dim>& origin,
134 const Quaternion& rotation) const;
135
136 friend bool Intersect<dim>(const Segment& s, const Point<dim>& p, bool proper);
137 friend bool Contains<dim>(const Point<dim>& p, const Segment& s, bool proper);
138
139 friend bool Intersect<dim>(const Segment& s, const AxisBox<dim>& b, bool proper);
140 friend bool Contains<dim>(const AxisBox<dim>& b, const Segment& s, bool proper);
141
142 friend bool Intersect<dim>(const Segment& s, const Ball<dim>& b, bool proper);
143 friend bool Contains<dim>(const Ball<dim>& b, const Segment& s, bool proper);
144
145 friend bool Intersect<dim>(const Segment& s1, const Segment& s2, bool proper);
146 friend bool Contains<dim>(const Segment& s1, const Segment& s2, bool proper);
147
148 friend bool Intersect<dim>(const RotBox<dim>& r, const Segment& s, bool proper);
149 friend bool Contains<dim>(const RotBox<dim>& r, const Segment& s, bool proper);
150 friend bool Contains<dim>(const Segment& s, const RotBox<dim>& r, bool proper);
151
152 friend bool Intersect<dim>(const Polygon<dim>& r, const Segment& s, bool proper);
153 friend bool Contains<dim>(const Polygon<dim>& p, const Segment& s, bool proper);
154 friend bool Contains<dim>(const Segment& s, const Polygon<dim>& p, bool proper);
155
156 private:
157
158 Point<dim> m_p1, m_p2;
159 };
160
161 template<int dim>
isEqualTo(const Segment<dim> & s,CoordType epsilon)162 inline bool Segment<dim>::isEqualTo(const Segment<dim>& s,
163 CoordType epsilon) const
164 {
165 return Equal(m_p1, s.m_p1, epsilon)
166 && Equal(m_p2, s.m_p2, epsilon);
167 }
168
169 } // namespace WFMath
170
171 #endif // WFMATH_SEGMENT_H
172