src/apps/haiku3d/MathUtils.cpp

   1 /*
   2  * Copyright 2008, Haiku Inc. All rights reserved.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *              Alexandre Deckner <alex@zappotek.com>
   7  */
   8
   9 // Some math utils, useful for animation
  10
  11
  12 #include "MathUtils.h"
  13
  14 #include <math.h>
  15
  16
  17 float
  18 MathUtils::EaseInOutCubic(float time, float start, float distance,
  19         float duration)
  20 {
  21         time /= duration  / 2.0;
  22         if (time < 1.0)
  23                 return distance / 2.0 * time * time * time + start;
  24         time -= 2.0;
  25         return distance / 2.0 * (time * time * time + 2.0) + start;
  26 }
  27
  28
  29 float
  30 MathUtils::EaseInOutQuart(float time, float start, float distance,
  31         float duration)
  32 {
  33         time /= duration  / 2;
  34
  35         if (time < 1)
  36                 return distance / 2 * time * time * time * time + start;
  37
  38         time -= 2;
  39
  40         return -distance / 2 * (time * time * time * time - 2) + start;
  41 }
  42
  43
  44 float
  45 MathUtils::EaseInOutQuint(float time, float start, float distance,
  46         float duration)
  47 {
  48         time /= duration  / 2;
  49         if (time < 1)
  50                 return distance / 2 * time * time * time * time * time + start;
  51         time -= 2;
  52         return distance / 2 *(time * time * time * time * time + 2) + start;
  53 }
  54
  55
  56 float
  57 MathUtils::EaseInOutSine(float time, float start, float distance,
  58         float duration)
  59 {
  60         return -distance / 2 * (cos(3.14159 * time / distance) - 1) + start;
  61 }