/** * @file lv_trigo.c * Basic trigonometric integer functions */ /********************* * INCLUDES *********************/ #include "lv_trigo.h" /********************* * DEFINES *********************/ /********************** * TYPEDEFS **********************/ /********************** * STATIC PROTOTYPES **********************/ /********************** * STATIC VARIABLES **********************/ static int16_t sin0_90_table[] = { 0, 572, 1144, 1715, 2286, 2856, 3425, 3993, 4560, 5126, 5690, 6252, 6813, 7371, 7927, 8481, 9032, 9580, 10126, 10668, 11207, 11743, 12275, 12803, 13328, 13848, 14364, 14876, 15383, 15886, 16383, 16876, 17364, 17846, 18323, 18794, 19260, 19720, 20173, 20621, 21062, 21497, 21925, 22347, 22762, 23170, 23571, 23964, 24351, 24730, 25101, 25465, 25821, 26169, 26509, 26841, 27165, 27481, 27788, 28087, 28377, 28659, 28932, 29196, 29451, 29697, 29934, 30162, 30381, 30591, 30791, 30982, 31163, 31335, 31498, 31650, 31794, 31927, 32051, 32165, 32269, 32364, 32448, 32523, 32587, 32642, 32687, 32722, 32747, 32762 }; /********************** * MACROS **********************/ /********************** * GLOBAL FUNCTIONS **********************/ /** * Return with sinus of an angle * @param angle * @return sinus of 'angle'. sin(-90) = -32767, sin(90) = 32767 */ int16_t lv_trigo_sin(int16_t angle) { int16_t ret = 0; angle = angle % 360; if(angle < 0) angle = 360 + angle; if(angle < 90){ ret = sin0_90_table[angle]; } else if(angle >= 90 && angle < 180) { angle = 179 - angle; ret = sin0_90_table[angle]; } else if(angle >= 180 && angle < 270) { angle = angle - 180; ret = - sin0_90_table[angle]; } else { /*angle >=270*/ angle = 359 - angle; ret = - sin0_90_table[angle]; } return ret; } /********************** * STATIC FUNCTIONS **********************/