engine/include/support/line3d.h

   1 // Copyright (C) 2002-2007 Nikolaus Gebhardt
   2 // This file is part of the "Irrlicht Engine".
   3 // For conditions of distribution and use, see copyright notice in irrlicht.h
   4
   5 #ifndef __IRR_LINE_3D_H_INCLUDED__
   6 #define __IRR_LINE_3D_H_INCLUDED__
   7
   8 #include "irrTypes.h"
   9 #include "vector3d.h"
  10
  11 namespace irr
  12 {
  13 namespace core
  14 {
  15
  16 //! 3D line between two points with intersection methods.
  17 template <class T>
  18 class line3d
  19 {
  20         public:
  21
  22                 // Constructors
  23
  24                 line3d() : start(0,0,0), end(1,1,1) {}
  25                 line3d(T xa, T ya, T za, T xb, T yb, T zb) : start(xa, ya, za), end(xb, yb, zb) {}
  26                 line3d(const vector3d<T>& start, const vector3d<T>& end) : start(start), end(end) {}
  27
  28                 // operators
  29
  30                 line3d<T> operator+(const vector3d<T>& point) const { return line3d<T>(start + point, end + point); }
  31                 line3d<T>& operator+=(const vector3d<T>& point) { start += point; end += point; return *this; }
  32
  33                 line3d<T> operator-(const vector3d<T>& point) const { return line3d<T>(start - point, end - point); }
  34                 line3d<T>& operator-=(const vector3d<T>& point) { start -= point; end -= point; return *this; }
  35
  36                 bool operator==(const line3d<T>& other) const { return (start==other.start && end==other.end) || (end==other.start && start==other.end);}
  37                 bool operator!=(const line3d<T>& other) const { return !(start==other.start && end==other.end) || (end==other.start && start==other.end);}
  38
  39                 // functions
  40
  41                 void setLine(const T& xa, const T& ya, const T& za, const T& xb, const T& yb, const T& zb) {start.set(xa, ya, za); end.set(xb, yb, zb);}
  42                 void setLine(const vector3d<T>& nstart, const vector3d<T>& nend) {start.set(nstart); end.set(nend);}
  43                 void setLine(const line3d<T>& line) {start.set(line.start); end.set(line.end);}
  44
  45                 //! Returns length of line
  46                 //! \return Returns length of line.
  47                 T getLength() const { return start.getDistanceFrom(end); }
  48
  49                 //! Returns sqared length of line
  50                 //! \return Returns sqared length of line.
  51                 T getLengthSQ() const { return start.getDistanceFromSQ(end); }
  52
  53                 //! Returns middle of line
  54                 vector3d<T> getMiddle() const
  55                 {
  56                         return (start + end) * (T)0.5;
  57                 }
  58
  59                 //! Returns vector of line
  60                 vector3d<T> getVector() const
  61                 {
  62                         return end - start;
  63                 }
  64
  65                 //! Returns if the given point is between start and end of the
  66                 //! line. Assumes that the point is already somewhere on the line.
  67                 bool isPointBetweenStartAndEnd(const vector3d<T>& point) const
  68                 {
  69                         return point.isBetweenPoints(start, end);
  70                 }
  71
  72                 //! Returns the closest point on this line to a point
  73                 vector3d<T> getClosestPoint(const vector3d<T>& point) const
  74                 {
  75                         vector3d<T> c = point - start;
  76                         vector3d<T> v = end - start;
  77                         T d = (T)v.getLength();
  78                         v /= d;
  79                         T t = v.dotProduct(c);
  80
  81                         if (t < (T)0.0)
  82                                 return start;
  83                         if (t > d)
  84                                 return end;
  85
  86                         v *= t;
  87                         return start + v;
  88                 }
  89
  90                 //! Returns if the line intersects with a shpere
  91                 //! \param sorigin: Origin of the shpere.
  92                 //! \param sradius: Radius of the sphere.
  93                 //! \param outdistance: The distance to the first intersection point.
  94                 //! \return Returns true if there is an intersection.
  95                 //! If there is one, the distance to the first intersection point
  96                 //! is stored in outdistance.
  97                 bool getIntersectionWithSphere(vector3d<T> sorigin, T sradius, f64& outdistance) const
  98                 {
  99                         const vector3d<T> q = sorigin - start;
 100                         T c = q.getLength();
 101                         T v = q.dotProduct(getVector().normalize());
 102                         T d = sradius * sradius - (c*c - v*v);
 103
 104                         if (d < 0.0)
 105                                 return false;
 106
 107                         outdistance = v - sqrt((f64)d);
 108                         return true;
 109                 }
 110
 111                 // member variables
 112
 113                 vector3d<T> start;
 114                 vector3d<T> end;
 115 };
 116
 117         //! Typedef for an f32 line.
 118         typedef line3d<f32> line3df;
 119         //! Typedef for an integer line.
 120         typedef line3d<s32> line3di;
 121
 122 } // end namespace core
 123 } // end namespace irr
 124
 125 #endif
 126