src/vector3.h

   1 //  vector3.h
   2 //
   3 //  C++ class for 3-element vectors
   4 //
   5 //  Copyright (C) 2000-2002, Mark R. Shinwell.
   6 //  Copyright (C) 2002-2004,2005,2006,2015 Olly Betts
   7 //
   8 //  This program is free software; you can redistribute it and/or modify
   9 //  it under the terms of the GNU General Public License as published by
  10 //  the Free Software Foundation; either version 2 of the License, or
  11 //  (at your option) any later version.
  12 //
  13 //  This program is distributed in the hope that it will be useful,
  14 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 //  GNU General Public License for more details.
  17 //
  18 //  You should have received a copy of the GNU General Public License
  19 //  along with this program; if not, write to the Free Software
  20 //  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21 //
  22
  23 #ifndef Vector3_h
  24 #define Vector3_h
  25
  26 #include <math.h>
  27
  28 class Vector3 {
  29 protected:
  30     double x, y, z;
  31
  32 public:
  33     Vector3() : x(0.0), y(0.0), z(0.0) { }
  34     Vector3(double a, double b, double c) : x(a), y(b), z(c) { }
  35
  36     double GetX() const { return x; }
  37     double GetY() const { return y; }
  38     double GetZ() const { return z; }
  39
  40     double magnitude() const {
  41         return sqrt(x*x + y*y + z*z);
  42     }
  43
  44     // Returns a value in *radians*.
  45     double gradient() const {
  46         return atan2(z, sqrt(x*x + y*y));
  47     }
  48
  49     void normalise();
  50
  51     void assign(double a, double b, double c) {
  52         x = a; y = b; z = c;
  53     }
  54
  55     void assign(const Vector3 &v) {
  56         *this = v;
  57     }
  58
  59     friend Vector3 operator-(const Vector3& o) {
  60         return Vector3(-o.x, -o.y, -o.z);
  61     }
  62     Vector3& operator*=(double);
  63     Vector3& operator/=(double);
  64     Vector3& operator+=(const Vector3&);
  65     Vector3& operator-=(const Vector3&);
  66
  67     friend Vector3 operator*(double, const Vector3&);
  68     friend Vector3 operator*(const Vector3& v, double f) {
  69         return f * v;
  70     }
  71     friend Vector3 operator*(const Vector3&, const Vector3&); // cross product
  72     friend Vector3 operator+(const Vector3&, const Vector3&);
  73     friend Vector3 operator-(const Vector3&, const Vector3&);
  74     friend bool operator==(const Vector3&, const Vector3&);
  75     friend bool operator<(const Vector3&, const Vector3&);
  76     friend double dot(const Vector3&, const Vector3&);
  77 };
  78
  79 inline bool operator==(const Vector3& a, const Vector3& b) {
  80     return a.x == b.x && a.y == b.y && a.z == b.z;
  81 }
  82
  83 // So we can use Vector3 as a key in a map...
  84 inline bool operator<(const Vector3& a, const Vector3& b) {
  85     if (a.x != b.x) return a.x < b.x;
  86     if (a.y != b.y) return a.y < b.y;
  87     return a.z < b.z;
  88 }
  89
  90 #endif