source/maths/MathUtil.h

   1 /* Copyright (C) 2022 Wildfire Games.
   2  * This file is part of 0 A.D.
   3  *
   4  * 0 A.D. is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * 0 A.D. is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef INCLUDED_MATHUTIL
  19 #define INCLUDED_MATHUTIL
  20
  21 #define DEGTORAD(a)                                     ((a) * ((float)M_PI/180.0f))
  22 #define RADTODEG(a)                                     ((a) * (180.0f/(float)M_PI))
  23 #define SQR(x)                                          ((x) * (x))
  24
  25 template<typename T>
  26 inline T Interpolate(const T& a, const T& b, float t)
  27 {
  28         return a + (b - a) * t;
  29 }
  30
  31 template<typename T>
  32 inline T Clamp(T value, T min, T max)
  33 {
  34         if (value <= min)
  35                 return min;
  36         else if (value >= max)
  37                 return max;
  38         return value;
  39 }
  40
  41 template<typename T>
  42 inline T SmoothStep(T edge0, T edge1, T value)
  43 {
  44         value = Clamp<T>((value - edge0) / (edge1 - edge0), 0, 1);
  45         return value * value * (3 - 2 * value);
  46 }
  47
  48 template<typename T>
  49 inline T Sign(const T value)
  50 {
  51     if (value > T(0))
  52         return T(1);
  53     if (value < T(0))
  54         return T(-1);
  55     return T(0);
  56 }
  57
  58 #endif // INCLUDED_MATHUTIL