text: /**
   * @file lv_math.c
   *
   */
  
  /*********************
   *      INCLUDES
   *********************/
  #include "lv_math.h"
  #include <stdbool.h>
  #include <stdlib.h>
  
  /*********************
   *      DEFINES
   *********************/
  
  /**********************
   *      TYPEDEFS
   **********************/
  
  /**********************
   *  STATIC PROTOTYPES
   **********************/
  
  /**********************
   *  STATIC VARIABLES
   **********************/
  static const 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, 32767};
  
  /**********************
   *      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 = 180 - angle;
          ret   = sin0_90_table[angle];
      } else if(angle >= 180 && angle < 270) {
          angle = angle - 180;
          ret   = -sin0_90_table[angle];
      } else { /*angle >=270*/
          angle = 360 - angle;
          ret   = -sin0_90_table[angle];
      }
  
      return ret;
  }
  
  /**
   * Calculate a value of a Cubic Bezier function.
   * @param t time in range of [0..LV_BEZIER_VAL_MAX]
   * @param u0 start values in range of [0..LV_BEZIER_VAL_MAX]
   * @param u1 control value 1 values in range of [0..LV_BEZIER_VAL_MAX]
   * @param u2 control value 2 in range of [0..LV_BEZIER_VAL_MAX]
   * @param u3 end values in range of [0..LV_BEZIER_VAL_MAX]
   * @return the value calculated from the given parameters in range of [0..LV_BEZIER_VAL_MAX]
   */
  int32_t lv_bezier3(uint32_t t, int32_t u0, int32_t u1, int32_t u2, int32_t u3)
  {
      uint32_t t_rem  = 1024 - t;
      uint32_t t_rem2 = (t_rem * t_rem) >> 10;
      uint32_t t_rem3 = (t_rem2 * t_rem) >> 10;
      uint32_t t2     = (t * t) >> 10;
      uint32_t t3     = (t2 * t) >> 10;
  
      uint32_t v1 = ((uint32_t)t_rem3 * u0) >> 10;
      uint32_t v2 = ((uint32_t)3 * t_rem2 * t * u1) >> 20;
      uint32_t v3 = ((uint32_t)3 * t_rem * t2 * u2) >> 20;
      uint32_t v4 = ((uint32_t)t3 * u3) >> 10;
  
      return v1 + v2 + v3 + v4;
  }
  
  /**
   * Calculate the integer square root of a number.
   * @param num
   * @return square root of 'num'
   */
  uint32_t lv_sqrt(uint32_t num)
  {
      // http://www.codecodex.com/wiki/Calculate_an_integer_square_root#C
      uint32_t root  = 0;
      uint32_t place = 0x40000000;
  
      while(place > num) place >>= 2;
      while(place) {
          if(num >= root + place) {
              num -= root + place;
              root += (place << 1);
          }
          root >>= 1;
          place >>= 2;
      }
      return root;
  }
  
  /**********************
   *   STATIC FUNCTIONS
   **********************/
  