math-extra.h 1.9 KB

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  1. /******************************************************************************
  2. Copyright (C) 2023 by Lain Bailey <lain@obsproject.com>
  3. This program is free software: you can redistribute it and/or modify
  4. it under the terms of the GNU General Public License as published by
  5. the Free Software Foundation, either version 2 of the License, or
  6. (at your option) any later version.
  7. This program is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  10. GNU General Public License for more details.
  11. You should have received a copy of the GNU General Public License
  12. along with this program. If not, see <http://www.gnu.org/licenses/>.
  13. ******************************************************************************/
  14. #pragma once
  15. #include "../util/c99defs.h"
  16. /*
  17. * A few general math functions that I couldn't really decide where to put.
  18. *
  19. * Polar/Cart conversion, torque functions (for smooth movement), percentage,
  20. * random floats.
  21. */
  22. #ifdef __cplusplus
  23. extern "C" {
  24. #endif
  25. struct vec2;
  26. struct vec3;
  27. EXPORT void polar_to_cart(struct vec3 *dst, const struct vec3 *v);
  28. EXPORT void cart_to_polar(struct vec3 *dst, const struct vec3 *v);
  29. EXPORT void norm_to_polar(struct vec2 *dst, const struct vec3 *norm);
  30. EXPORT void polar_to_norm(struct vec3 *dst, const struct vec2 *polar);
  31. EXPORT float calc_torquef(float val1, float val2, float torque, float min_adjust, float t);
  32. EXPORT void calc_torque(struct vec3 *dst, const struct vec3 *v1, const struct vec3 *v2, float torque, float min_adjust,
  33. float t);
  34. static inline float get_percentage(float start, float end, float mid)
  35. {
  36. return (mid - start) / (end - start);
  37. }
  38. static inline float get_percentagei(int start, int end, int mid)
  39. {
  40. return (float)(mid - start) / (float)(end - start);
  41. }
  42. EXPORT float rand_float(int positive_only);
  43. #ifdef __cplusplus
  44. }
  45. #endif