Source/System/Image/Squish/maths.h

   1 /* -----------------------------------------------------------------------------
   2
   3         Copyright (c) 2006 Simon Brown                          si@sjbrown.co.uk
   4
   5         Permission is hereby granted, free of charge, to any person obtaining
   6         a copy of this software and associated documentation files (the
   7         "Software"), to deal in the Software without restriction, including
   8         without limitation the rights to use, copy, modify, merge, publish,
   9         distribute, sublicense, and/or sell copies of the Software, and to
  10         permit persons to whom the Software is furnished to do so, subject to
  11         the following conditions:
  12
  13         The above copyright notice and this permission notice shall be included
  14         in all copies or substantial portions of the Software.
  15
  16         THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17         OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18         MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  19         IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  20         CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  21         TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  22         SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23
  24    -------------------------------------------------------------------------- */
  25
  26 #ifndef SQUISH_MATHS_H
  27 #define SQUISH_MATHS_H
  28
  29 #include <cmath>
  30 #include <algorithm>
  31 #include "config.h"
  32
  33 namespace osgsquish {
  34
  35 class Vec3
  36 {
  37 public:
  38         typedef Vec3 const& Arg;
  39
  40         Vec3() : m_x(0.f), m_y(0.f), m_z(0.f)
  41         {
  42         }
  43
  44         explicit Vec3( float s ) : m_x(s), m_y(s), m_z(s)
  45         {
  46         }
  47
  48         Vec3( float x, float y, float z )  : m_x(x), m_y(y), m_z(z)
  49         {
  50         }
  51
  52         float X() const { return m_x; }
  53         float Y() const { return m_y; }
  54         float Z() const { return m_z; }
  55
  56         Vec3 operator-() const
  57         {
  58                 return Vec3( -m_x, -m_y, -m_z );
  59         }
  60
  61         Vec3& operator+=( Arg v )
  62         {
  63                 m_x += v.m_x;
  64                 m_y += v.m_y;
  65                 m_z += v.m_z;
  66                 return *this;
  67         }
  68
  69         Vec3& operator-=( Arg v )
  70         {
  71                 m_x -= v.m_x;
  72                 m_y -= v.m_y;
  73                 m_z -= v.m_z;
  74                 return *this;
  75         }
  76
  77         Vec3& operator*=( Arg v )
  78         {
  79                 m_x *= v.m_x;
  80                 m_y *= v.m_y;
  81                 m_z *= v.m_z;
  82                 return *this;
  83         }
  84
  85         Vec3& operator*=( float s )
  86         {
  87                 m_x *= s;
  88                 m_y *= s;
  89                 m_z *= s;
  90                 return *this;
  91         }
  92
  93         Vec3& operator/=( Arg v )
  94         {
  95                 m_x /= v.m_x;
  96                 m_y /= v.m_y;
  97                 m_z /= v.m_z;
  98                 return *this;
  99         }
 100
 101         Vec3& operator/=( float s )
 102         {
 103                 float t = 1.0f/s;
 104                 m_x *= t;
 105                 m_y *= t;
 106                 m_z *= t;
 107                 return *this;
 108         }
 109
 110         friend Vec3 operator+( Arg left, Arg right )
 111         {
 112                 Vec3 copy( left );
 113                 return copy += right;
 114         }
 115
 116         friend Vec3 operator-( Arg left, Arg right )
 117         {
 118                 Vec3 copy( left );
 119                 return copy -= right;
 120         }
 121
 122         friend Vec3 operator*( Arg left, Arg right )
 123         {
 124                 Vec3 copy( left );
 125                 return copy *= right;
 126         }
 127
 128         friend Vec3 operator*( Arg left, float right )
 129         {
 130                 Vec3 copy( left );
 131                 return copy *= right;
 132         }
 133
 134         friend Vec3 operator*( float left, Arg right )
 135         {
 136                 Vec3 copy( right );
 137                 return copy *= left;
 138         }
 139
 140         friend Vec3 operator/( Arg left, Arg right )
 141         {
 142                 Vec3 copy( left );
 143                 return copy /= right;
 144         }
 145
 146         friend Vec3 operator/( Arg left, float right )
 147         {
 148                 Vec3 copy( left );
 149                 return copy /= right;
 150         }
 151
 152         friend float Dot( Arg left, Arg right )
 153         {
 154                 return left.m_x*right.m_x + left.m_y*right.m_y + left.m_z*right.m_z;
 155         }
 156
 157         friend Vec3 Min( Arg left, Arg right )
 158         {
 159                 return Vec3(
 160                         std::min( left.m_x, right.m_x ),
 161                         std::min( left.m_y, right.m_y ),
 162                         std::min( left.m_z, right.m_z )
 163                 );
 164         }
 165
 166         friend Vec3 Max( Arg left, Arg right )
 167         {
 168                 return Vec3(
 169                         std::max( left.m_x, right.m_x ),
 170                         std::max( left.m_y, right.m_y ),
 171                         std::max( left.m_z, right.m_z )
 172                 );
 173         }
 174
 175         friend Vec3 Truncate( Arg v )
 176         {
 177                 return Vec3(
 178                         v.m_x > 0.0f ? std::floor( v.m_x ) : std::ceil( v.m_x ),
 179                         v.m_y > 0.0f ? std::floor( v.m_y ) : std::ceil( v.m_y ),
 180                         v.m_z > 0.0f ? std::floor( v.m_z ) : std::ceil( v.m_z )
 181                 );
 182         }
 183
 184 private:
 185         float m_x;
 186         float m_y;
 187         float m_z;
 188 };
 189
 190 inline float LengthSquared( Vec3::Arg v )
 191 {
 192         return Dot( v, v );
 193 }
 194
 195 class Sym3x3
 196 {
 197 public:
 198         Sym3x3()
 199         {
 200         }
 201
 202         Sym3x3( float s )
 203         {
 204                 for( int i = 0; i < 6; ++i )
 205                         m_x[i] = s;
 206         }
 207
 208         float operator[]( int index ) const
 209         {
 210                 return m_x[index];
 211         }
 212
 213         float& operator[]( int index )
 214         {
 215                 return m_x[index];
 216         }
 217
 218 private:
 219         float m_x[6];
 220 };
 221
 222 Sym3x3 ComputeWeightedCovariance( int n, Vec3 const* points, float const* weights );
 223 Vec3 ComputePrincipleComponent( Sym3x3 const& matrix );
 224
 225 } // namespace squish
 226
 227 #endif // ndef SQUISH_MATHS_H