1 // axisbox.h (An axis-aligned box)
2 //
3 // The WorldForge Project
4 // Copyright (C) 2000, 2001 The WorldForge Project
5 //
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10 //
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15 //
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17 // along with this program; if not, write to the Free Software
18 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 //
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21 // the Worldforge Web Site at http://www.worldforge.org.
22 //
23
24 // Author: Ron Steinke
25
26 // The implementation of this class is based on the geometric
27 // parts of the Tree and Placement classes from stage/shepherd/sylvanus
28
29 #ifndef WFMATH_AXIS_BOX_H
30 #define WFMATH_AXIS_BOX_H
31
32 #include <wfmath/intersect_decls.h>
33
34 #include <iosfwd>
35
36 namespace WFMath {
37
38 template<int dim>
39 bool Intersection(const AxisBox<dim>& a1, const AxisBox<dim>& a2, AxisBox<dim>& out);
40 template<int dim>
41 AxisBox<dim> Union(const AxisBox<dim>& a1, const AxisBox<dim>& a2);
42
43 template<int dim>
44 std::ostream& operator<<(std::ostream& os, const AxisBox<dim>& m);
45 template<int dim>
46 std::istream& operator>>(std::istream& is, AxisBox<dim>& m);
47
48 /// Get the axis-aligned bounding box for a set of boxes
49 template<int dim, template<class, class> class container>
50 AxisBox<dim> BoundingBox(const container<AxisBox<dim>, std::allocator<AxisBox<dim> > >& c);
51
52 /// Get the axis-aligned bounding box for a set of points
53 template<int dim, template<class, class> class container>
54 AxisBox<dim> BoundingBox(const container<Point<dim>, std::allocator<Point<dim> > >& c);
55
56 /// A dim dimensional axis-aligned box
57 /**
58 * This class implements the full shape interface, as described in
59 * the fake class Shape, with the exception of the rotation functions.
60 **/
61 template<int dim = 3>
62 class AxisBox
63 {
64 public:
65 /// Construct an uninitialized box
AxisBox()66 AxisBox() : m_low(), m_high() {}
67 /// Construct a box with opposite corners p1 and p2
68 AxisBox(const Point<dim>& p1, const Point<dim>& p2, bool ordered = false) :
m_low()69 m_low(), m_high()
70 {setCorners(p1, p2, ordered);}
71 /// Construct a copy of a box
AxisBox(const AxisBox & a)72 AxisBox(const AxisBox& a) : m_low(a.m_low), m_high(a.m_high) {}
73 /// Construct a box from an object passed by Atlas
74 explicit AxisBox(const AtlasInType& a);
75
76 friend std::ostream& operator<< <dim>(std::ostream& os, const AxisBox& a);
77 friend std::istream& operator>> <dim>(std::istream& is, AxisBox& a);
78
79 /// Create an Atlas object from the box
80 AtlasOutType toAtlas() const;
81 /// Set the box's value to that given by an Atlas object
82 void fromAtlas(const AtlasInType& a);
83
84 AxisBox& operator=(const AxisBox& a)
85 {m_low = a.m_low; m_high = a.m_high; return *this;}
86
87 bool isEqualTo(const AxisBox& b, CoordType epsilon = numeric_constants<CoordType>::epsilon()) const;
88 bool operator==(const AxisBox& a) const {return isEqualTo(a);}
89 bool operator!=(const AxisBox& a) const {return !isEqualTo(a);}
90
isValid()91 bool isValid() const {return m_low.isValid() && m_high.isValid();}
92
93 // Descriptive characteristics
94
numCorners()95 size_t numCorners() const {return 1 << dim;}
96 Point<dim> getCorner(size_t i) const;
getCenter()97 Point<dim> getCenter() const {return Midpoint(m_low, m_high);}
98
99 /// Get a reference to corner 0
lowCorner()100 const Point<dim>& lowCorner() const {return m_low;}
lowCorner()101 Point<dim>& lowCorner() {return m_low;}
102 /// Get a reference to corner (2^dim)-1
highCorner()103 const Point<dim>& highCorner() const {return m_high;}
highCorner()104 Point<dim>& highCorner() {return m_high;}
105
106 /// Get the lower bound of the box on the i'th axis
lowerBound(const int axis)107 CoordType lowerBound(const int axis) const {return m_low[axis];}
108 /// Get the upper bound of the box on the i'th axis
upperBound(const int axis)109 CoordType upperBound(const int axis) const {return m_high[axis];}
110
111 /// Set the box to have opposite corners p1 and p2
112 /**
113 * The 'ordered' variable may be set to true if p1[i] <= p2[i] for all
114 * i. It is always safe to leave 'ordered' as false, it is a speed
115 * optimization primarily intended for use inside the library.
116 **/
117 AxisBox& setCorners(const Point<dim>& p1, const Point<dim>& p2,
118 bool ordered = false);
119
120 // Movement functions
121
shift(const Vector<dim> & v)122 AxisBox& shift(const Vector<dim>& v)
123 {m_low += v; m_high += v; return *this;}
moveCornerTo(const Point<dim> & p,size_t corner)124 AxisBox& moveCornerTo(const Point<dim>& p, size_t corner)
125 {return shift(p - getCorner(corner));}
moveCenterTo(const Point<dim> & p)126 AxisBox& moveCenterTo(const Point<dim>& p)
127 {return shift(p - getCenter());}
128
129 // No rotation functions, this shape can't rotate
130
131 // Intersection functions
132
boundingBox()133 AxisBox boundingBox() const {return *this;}
134 Ball<dim> boundingSphere() const;
135 Ball<dim> boundingSphereSloppy() const;
136
toParentCoords(const Point<dim> & origin)137 AxisBox toParentCoords(const Point<dim>& origin) const
138 {return AxisBox(m_low.toParentCoords(origin), m_high.toParentCoords(origin), true);}
toParentCoords(const AxisBox<dim> & coords)139 AxisBox toParentCoords(const AxisBox<dim>& coords) const
140 {return AxisBox(m_low.toParentCoords(coords), m_high.toParentCoords(coords), true);}
141
142 // toLocal is just like toParent, expect we reverse the order of
143 // translation and rotation and use the opposite sense of the rotation
144 // matrix
145
toLocalCoords(const Point<dim> & origin)146 AxisBox toLocalCoords(const Point<dim>& origin) const
147 {return AxisBox(m_low.toLocalCoords(origin), m_high.toLocalCoords(origin), true);}
toLocalCoords(const AxisBox<dim> & coords)148 AxisBox toLocalCoords(const AxisBox<dim>& coords) const
149 {return AxisBox(m_low.toLocalCoords(coords), m_high.toLocalCoords(coords), true);}
150
151 /// Return true if the boxes intersect, and set 'out' to their intersection
152 friend bool Intersection<dim>(const AxisBox& a1, const AxisBox& a2, AxisBox& out);
153 /// Get the minimal box that contains a1 and a2
154 friend AxisBox Union<dim>(const AxisBox& a1, const AxisBox& a2);
155
156 friend bool Intersect<dim>(const AxisBox& b, const Point<dim>& p, bool proper);
157 friend bool Contains<dim>(const Point<dim>& p, const AxisBox& b, bool proper);
158
159 friend bool Intersect<dim>(const AxisBox& b1, const AxisBox& b2, bool proper);
160 friend bool Contains<dim>(const AxisBox& outer, const AxisBox& inner, bool proper);
161
162 friend bool Intersect<dim>(const Ball<dim>& b, const AxisBox& a, bool proper);
163 friend bool Contains<dim>(const Ball<dim>& b, const AxisBox& a, bool proper);
164 friend bool Contains<dim>(const AxisBox& a, const Ball<dim>& b, bool proper);
165
166 friend bool Intersect<dim>(const Segment<dim>& s, const AxisBox& b, bool proper);
167 friend bool Contains<dim>(const Segment<dim>& s, const AxisBox& b, bool proper);
168
169 friend bool Intersect<dim>(const RotBox<dim>& r, const AxisBox& b, bool proper);
170 friend bool Contains<dim>(const RotBox<dim>& r, const AxisBox& b, bool proper);
171 friend bool Contains<dim>(const AxisBox& b, const RotBox<dim>& r, bool proper);
172
173 friend bool Intersect<dim>(const Polygon<dim>& p, const AxisBox& b, bool proper);
174 friend bool Contains<dim>(const Polygon<dim>& p, const AxisBox& b, bool proper);
175 friend bool Contains<dim>(const AxisBox& b, const Polygon<dim>& p, bool proper);
176
177 private:
178
179 Point<dim> m_low, m_high;
180 };
181
182 template<int dim>
isEqualTo(const AxisBox<dim> & b,CoordType epsilon)183 inline bool AxisBox<dim>::isEqualTo(const AxisBox<dim>& b, CoordType epsilon) const
184 {
185 return Equal(m_low, b.m_low, epsilon)
186 && Equal(m_high, b.m_high, epsilon);
187 }
188
189 } // namespace WFMath
190
191 #endif // WFMATH_AXIS_BOX_H
192