/src/ftk_interpolator_bounce.c

http://ftk.googlecode.com/ · C · 63 lines · 26 code · 8 blank · 29 comment · 6 complexity · 1f8ec1459af9e6d1ed76565fc6745cfe MD5 · raw file

  1. /*
  2. * File: ftk_interpolator_bounce.h
  3. * Author: Li XianJing <xianjimli@hotmail.com>
  4. * Brief: bounce interpolator for animation.
  5. *
  6. * Copyright (c) 2009 - 2011 Li XianJing <xianjimli@hotmail.com>
  7. *
  8. * Licensed under the Academic Free License version 2.1
  9. *
  10. * This program is free software; you can redistribute it and/or modify
  11. * it under the terms of the GNU General Public License as published by
  12. * the Free Software Foundation; either version 2 of the License, or
  13. * (at your option) any later version.
  14. *
  15. * This program is distributed in the hope that it will be useful,
  16. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18. * GNU General Public License for more details.
  19. *
  20. * You should have received a copy of the GNU General Public License
  21. * along with this program; if not, write to the Free Software
  22. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23. */
  24. /*
  25. * History:
  26. * ================================================================
  27. * 2011-03-20 Li XianJing <xianjimli@hotmail.com> created
  28. *
  29. */
  30. #include "ftk_interpolator.h"
  31. static float ftk_interpolator_bounce_calc(float percent)
  32. {
  33. return 8 * percent * percent;
  34. }
  35. static float ftk_interpolator_bounce_get(FtkInterpolator* thiz, float percent)
  36. {
  37. percent *= 1.1226f;
  38. if (percent < 0.3535f)
  39. return ftk_interpolator_bounce_calc(percent);
  40. else if (percent < 0.7408f)
  41. return ftk_interpolator_bounce_calc(percent - 0.54719f) + 0.7f;
  42. else if (percent < 0.9644f)
  43. return ftk_interpolator_bounce_calc(percent - 0.8526f) + 0.9f;
  44. else
  45. return ftk_interpolator_bounce_calc(percent - 1.0435f) + 0.95f;
  46. }
  47. const static FtkInterpolator s_interpolator_bounce =
  48. {
  49. ftk_interpolator_bounce_get,
  50. NULL
  51. };
  52. FtkInterpolator* ftk_interpolator_bounce_create(void)
  53. {
  54. return (FtkInterpolator*)&s_interpolator_bounce;
  55. }