lv_trigo.c 2.0 KB

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  1. /**
  2. * @file lv_trigo.c
  3. * Basic trigonometric integer functions
  4. */
  5. /*********************
  6. * INCLUDES
  7. *********************/
  8. #include "lv_trigo.h"
  9. /*********************
  10. * DEFINES
  11. *********************/
  12. /**********************
  13. * TYPEDEFS
  14. **********************/
  15. /**********************
  16. * STATIC PROTOTYPES
  17. **********************/
  18. /**********************
  19. * STATIC VARIABLES
  20. **********************/
  21. static int16_t sin0_90_table[] =
  22. {
  23. 0, 572, 1144, 1715, 2286, 2856, 3425, 3993, 4560, 5126,
  24. 5690, 6252, 6813, 7371, 7927, 8481, 9032, 9580, 10126, 10668,
  25. 11207, 11743, 12275, 12803, 13328, 13848, 14364, 14876, 15383, 15886,
  26. 16383, 16876, 17364, 17846, 18323, 18794, 19260, 19720, 20173, 20621,
  27. 21062, 21497, 21925, 22347, 22762, 23170, 23571, 23964, 24351, 24730,
  28. 25101, 25465, 25821, 26169, 26509, 26841, 27165, 27481, 27788, 28087,
  29. 28377, 28659, 28932, 29196, 29451, 29697, 29934, 30162, 30381, 30591,
  30. 30791, 30982, 31163, 31335, 31498, 31650, 31794, 31927, 32051, 32165,
  31. 32269, 32364, 32448, 32523, 32587, 32642, 32687, 32722, 32747, 32762
  32. };
  33. /**********************
  34. * MACROS
  35. **********************/
  36. /**********************
  37. * GLOBAL FUNCTIONS
  38. **********************/
  39. /**
  40. * Return with sinus of an angle
  41. * @param angle
  42. * @return sinus of 'angle'. sin(-90) = -32767, sin(90) = 32767
  43. */
  44. int16_t lv_trigo_sin(int16_t angle)
  45. {
  46. int16_t ret = 0;
  47. angle = angle % 360;
  48. if(angle < 0) angle = 360 + angle;
  49. if(angle < 90){
  50. ret = sin0_90_table[angle];
  51. } else if(angle >= 90 && angle < 180)
  52. {
  53. angle = 179 - angle;
  54. ret = sin0_90_table[angle];
  55. } else if(angle >= 180 && angle < 270)
  56. {
  57. angle = angle - 180;
  58. ret = - sin0_90_table[angle];
  59. } else { /*angle >=270*/
  60. angle = 359 - angle;
  61. ret = - sin0_90_table[angle];
  62. }
  63. return ret;
  64. }
  65. /**********************
  66. * STATIC FUNCTIONS
  67. **********************/