WFMath: ball.h Source File

00001 // ball.h (A n-dimensional ball)
00002 //
00003 //  The WorldForge Project
00004 //  Copyright (C) 2000, 2001  The WorldForge Project
00005 //
00006 //  This program is free software; you can redistribute it and/or modify
00007 //  it under the terms of the GNU General Public License as published by
00008 //  the Free Software Foundation; either version 2 of the License, or
00009 //  (at your option) any later version.
00010 //
00011 //  This program is distributed in the hope that it will be useful,
00012 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 //  GNU General Public License for more details.
00015 //
00016 //  You should have received a copy of the GNU General Public License
00017 //  along with this program; if not, write to the Free Software
00018 //  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00019 //
00020 //  For information about WorldForge and its authors, please contact
00021 //  the Worldforge Web Site at http://www.worldforge.org.
00022 //
00023 
00024 // Author: Ron Steinke
00025 
00026 #ifndef WFMATH_BALL_H
00027 #define WFMATH_BALL_H
00028 
00029 #include <wfmath/point.h>
00030 #include <wfmath/intersect_decls.h>
00031 
00032 namespace WFMath {
00033 
00034 template<int dim> class Ball;
00035 
00037 template<int dim, template<class, class> class container>
00038 Ball<dim> BoundingSphere(const container<Point<dim>, std::allocator<Point<dim> > >& c);
00040 template<int dim, template<class, class> class container>
00041 Ball<dim> BoundingSphereSloppy(const container<Point<dim>, std::allocator<Point<dim> > >& c);
00042 
00043 template<int dim>
00044 std::ostream& operator<<(std::ostream& os, const Ball<dim>& m);
00045 template<int dim>
00046 std::istream& operator>>(std::istream& is, Ball<dim>& m);
00047 
00049 
00059 template<int dim = 3>
00060 class Ball
00061 {
00062  public:
00064   Ball() : m_center(), m_radius(0.f) {}
00066   Ball(const Point<dim>& center, CoordType radius)
00067   : m_center(center), m_radius(radius) { if (radius < 0) m_center.setValid(false); }
00069   Ball(const Ball& b) : m_center(b.m_center), m_radius(b.m_radius) {}
00071   explicit Ball(const AtlasInType& a);
00072 
00073   ~Ball() {}
00074 
00075   friend std::ostream& operator<< <dim>(std::ostream& os, const Ball& b);
00076   friend std::istream& operator>> <dim>(std::istream& is, Ball& b);
00077 
00079   AtlasOutType toAtlas() const;
00081   void fromAtlas(const AtlasInType& a);
00082 
00083   Ball& operator=(const Ball& b)
00084   {m_radius = b.m_radius; m_center = b.m_center; return *this;}
00085 
00086   bool isEqualTo(const Ball& b, CoordType epsilon = numeric_constants<CoordType>::epsilon()) const;
00087 
00088   bool operator==(const Ball& b) const  {return isEqualTo(b);}
00089   bool operator!=(const Ball& b) const  {return !isEqualTo(b);}
00090 
00091   bool isValid() const {return m_center.isValid();}
00092 
00093   // Descriptive characteristics
00094 
00095   size_t numCorners() const {return 0;}
00096   // This next function exists so that Ball can be used by code
00097   // that finds the number of corners with numCorners(), and does something
00098   // with each corner with getCorner(). No idea how useful that is, but
00099   // it's not a particularly complicated function to write.
00100   Point<dim> getCorner(size_t) const {return m_center;}
00101   Point<dim> getCenter() const {return m_center;}
00102 
00104   const Point<dim>& center() const {return m_center;}
00106   Point<dim>& center() {return m_center;}
00108   CoordType radius() const {return m_radius;}
00110   CoordType& radius() {return m_radius;}
00111 
00112   // Movement functions
00113 
00114   Ball& shift(const Vector<dim>& v) {m_center += v; return *this;}
00115   Ball& moveCornerTo(const Point<dim>&, size_t) {return *this;}
00116   Ball& moveCenterTo(const Point<dim>& p) {m_center = p; return *this;}
00117 
00118   Ball& rotateCorner(const RotMatrix<dim>&, size_t) {return *this;}
00119   Ball& rotateCenter(const RotMatrix<dim>&) {return *this;}
00120   Ball& rotatePoint(const RotMatrix<dim>& m, const Point<dim>& p)
00121   {m_center.rotate(m, p); return *this;}
00122 
00123   // 3D rotation function
00124   Ball& rotateCorner(const Quaternion&, size_t corner);
00125   Ball& rotateCenter(const Quaternion&);
00126   Ball& rotatePoint(const Quaternion& q, const Point<dim>& p);
00127 
00128   // Intersection functions
00129 
00130   AxisBox<dim> boundingBox() const;
00131   Ball boundingSphere() const           {return *this;}
00132   Ball boundingSphereSloppy() const     {return *this;}
00133 
00134   Ball toParentCoords(const Point<dim>& origin,
00135       const RotMatrix<dim>& rotation = RotMatrix<dim>().identity()) const
00136         {return Ball(m_center.toParentCoords(origin, rotation), m_radius);}
00137   Ball toParentCoords(const AxisBox<dim>& coords) const
00138         {return Ball(m_center.toParentCoords(coords), m_radius);}
00139   Ball toParentCoords(const RotBox<dim>& coords) const
00140         {return Ball(m_center.toParentCoords(coords), m_radius);}
00141 
00142   // toLocal is just like toParent, expect we reverse the order of
00143   // translation and rotation and use the opposite sense of the rotation
00144   // matrix
00145 
00146   Ball toLocalCoords(const Point<dim>& origin,
00147       const RotMatrix<dim>& rotation = RotMatrix<dim>().identity()) const
00148         {return Ball(m_center.toLocalCoords(origin, rotation), m_radius);}
00149   Ball toLocalCoords(const AxisBox<dim>& coords) const
00150         {return Ball(m_center.toLocalCoords(coords), m_radius);}
00151   Ball toLocalCoords(const RotBox<dim>& coords) const
00152         {return Ball(m_center.toLocalCoords(coords), m_radius);}
00153 
00154   // 3D only
00155   Ball toParentCoords(const Point<dim>& origin, const Quaternion& rotation) const;
00156   Ball toLocalCoords(const Point<dim>& origin, const Quaternion& rotation) const;
00157 
00158   friend bool Intersect<dim>(const Ball& b, const Point<dim>& p, bool proper);
00159   friend bool Contains<dim>(const Point<dim>& p, const Ball& b, bool proper);
00160 
00161   friend bool Intersect<dim>(const Ball& b, const AxisBox<dim>& a, bool proper);
00162   friend bool Contains<dim>(const Ball& b, const AxisBox<dim>& a, bool proper);
00163   friend bool Contains<dim>(const AxisBox<dim>& a, const Ball& b, bool proper);
00164 
00165   friend bool Intersect<dim>(const Ball& b1, const Ball& b2, bool proper);
00166   friend bool Contains<dim>(const Ball& outer, const Ball& inner, bool proper);
00167 
00168   friend bool Intersect<dim>(const Segment<dim>& s, const Ball& b, bool proper);
00169   friend bool Contains<dim>(const Segment<dim>& s, const Ball& b, bool proper);
00170 
00171   friend bool Intersect<dim>(const RotBox<dim>& r, const Ball& b, bool proper);
00172   friend bool Contains<dim>(const RotBox<dim>& r, const Ball& b, bool proper);
00173   friend bool Contains<dim>(const Ball& b, const RotBox<dim>& r, bool proper);
00174 
00175   friend bool Intersect<dim>(const Polygon<dim>& p, const Ball& b, bool proper);
00176   friend bool Contains<dim>(const Polygon<dim>& p, const Ball& b, bool proper);
00177   friend bool Contains<dim>(const Ball& b, const Polygon<dim>& p, bool proper);
00178 
00179  private:
00180 
00181   Point<dim> m_center;
00182   CoordType m_radius;
00183 };
00184 
00185 template<int dim>
00186 inline bool Ball<dim>::isEqualTo(const Ball<dim>& b, CoordType epsilon) const
00187 {
00188   return Equal(m_center, b.m_center, epsilon)
00189       && Equal(m_radius, b.m_radius, epsilon);
00190 }
00191 
00192 } // namespace WFMath
00193 
00194 #endif  // WFMATH_BALL_H