text: /**
   * @file lv_area.c
   *
   */
  
  /*********************
   *      INCLUDES
   *********************/
  #ifdef LV_CONF_INCLUDE_SIMPLE
  #include "lv_conf.h"
  #else
  #include "../../lv_conf.h"
  #endif
  
  #include "lv_area.h"
  #include "lv_math.h"
  
  /*********************
   *      DEFINES
   *********************/
  
  /**********************
   *      TYPEDEFS
   **********************/
  
  /**********************
   *  STATIC PROTOTYPES
   **********************/
  
  /**********************
   *  STATIC VARIABLES
   **********************/
  
  /**********************
   *      MACROS
   **********************/
  
  /**********************
   *   GLOBAL FUNCTIONS
   **********************/
  
  /**
   * Initialize an area
   * @param area_p pointer to an area
   * @param x1 left coordinate of the area
   * @param y1 top coordinate of the area
   * @param x2 right coordinate of the area
   * @param y2 bottom coordinate of the area
   */
  void lv_area_set(lv_area_t * area_p, lv_coord_t x1, lv_coord_t y1, lv_coord_t x2, lv_coord_t y2)
  {
      area_p->x1 = x1;
      area_p->y1 = y1;
      area_p->x2 = x2;
      area_p->y2 = y2;
  }
  
  /**
   * Set the width of an area
   * @param area_p pointer to an area
   * @param w the new width of the area (w == 1 makes x1 == x2)
   */
  void lv_area_set_width(lv_area_t * area_p, lv_coord_t w)
  {
      area_p->x2 = area_p->x1 + w - 1;
  }
  
  /**
   * Set the height of an area
   * @param area_p pointer to an area
   * @param h the new height of the area (h == 1 makes y1 == y2)
   */
  void lv_area_set_height(lv_area_t * area_p, lv_coord_t h)
  {
      area_p->y2 = area_p->y1 + h - 1;
  }
  
  /**
   * Set the position of an area (width and height will be kept)
   * @param area_p pointer to an area
   * @param x the new x coordinate of the area
   * @param y the new y coordinate of the area
   */
  void lv_area_set_pos(lv_area_t * area_p, lv_coord_t x, lv_coord_t y)
  {
      lv_coord_t w = lv_area_get_width(area_p);
      lv_coord_t h = lv_area_get_height(area_p);
      area_p->x1   = x;
      area_p->y1   = y;
      lv_area_set_width(area_p, w);
      lv_area_set_height(area_p, h);
  }
  
  /**
   * Return with area of an area (x * y)
   * @param area_p pointer to an area
   * @return size of area
   */
  uint32_t lv_area_get_size(const lv_area_t * area_p)
  {
      uint32_t size;
  
      size = (uint32_t)(area_p->x2 - area_p->x1 + 1) * (area_p->y2 - area_p->y1 + 1);
  
      return size;
  }
  
  /**
   * Get the common parts of two areas
   * @param res_p pointer to an area, the result will be stored here
   * @param a1_p pointer to the first area
   * @param a2_p pointer to the second area
   * @return false: the two area has NO common parts, res_p is invalid
   */
  bool lv_area_intersect(lv_area_t * res_p, const lv_area_t * a1_p, const lv_area_t * a2_p)
  {
      /* Get the smaller area from 'a1_p' and 'a2_p' */
      res_p->x1 = LV_MATH_MAX(a1_p->x1, a2_p->x1);
      res_p->y1 = LV_MATH_MAX(a1_p->y1, a2_p->y1);
      res_p->x2 = LV_MATH_MIN(a1_p->x2, a2_p->x2);
      res_p->y2 = LV_MATH_MIN(a1_p->y2, a2_p->y2);
  
      /*If x1 or y1 greater then x2 or y2 then the areas union is empty*/
      bool union_ok = true;
      if((res_p->x1 > res_p->x2) || (res_p->y1 > res_p->y2)) {
          union_ok = false;
      }
  
      return union_ok;
  }
  /**
   * Join two areas into a third which involves the other two
   * @param res_p pointer to an area, the result will be stored here
   * @param a1_p pointer to the first area
   * @param a2_p pointer to the second area
   */
  void lv_area_join(lv_area_t * a_res_p, const lv_area_t * a1_p, const lv_area_t * a2_p)
  {
      a_res_p->x1 = LV_MATH_MIN(a1_p->x1, a2_p->x1);
      a_res_p->y1 = LV_MATH_MIN(a1_p->y1, a2_p->y1);
      a_res_p->x2 = LV_MATH_MAX(a1_p->x2, a2_p->x2);
      a_res_p->y2 = LV_MATH_MAX(a1_p->y2, a2_p->y2);
  }
  
  /**
   * Check if a point is on an area
   * @param a_p pointer to an area
   * @param p_p pointer to a point
   * @return false:the point is out of the area
   */
  bool lv_area_is_point_on(const lv_area_t * a_p, const lv_point_t * p_p)
  {
      bool is_on = false;
  
      if((p_p->x >= a_p->x1 && p_p->x <= a_p->x2) && ((p_p->y >= a_p->y1 && p_p->y <= a_p->y2))) {
          is_on = true;
      }
  
      return is_on;
  }
  
  /**
   * Check if two area has common parts
   * @param a1_p pointer to an area.
   * @param a2_p pointer to an other area
   * @return false: a1_p and a2_p has no common parts
   */
  bool lv_area_is_on(const lv_area_t * a1_p, const lv_area_t * a2_p)
  {
      if((a1_p->x1 <= a2_p->x2) && (a1_p->x2 >= a2_p->x1) && (a1_p->y1 <= a2_p->y2) && (a1_p->y2 >= a2_p->y1)) {
          return true;
      } else {
          return false;
      }
  }
  
  /**
   * Check if an area is fully on an other
   * @param ain_p pointer to an area which could be in 'aholder_p'
   * @param aholder pointer to an area which could involve 'ain_p'
   * @return
   */
  bool lv_area_is_in(const lv_area_t * ain_p, const lv_area_t * aholder_p)
  {
      bool is_in = false;
  
      if(ain_p->x1 >= aholder_p->x1 && ain_p->y1 >= aholder_p->y1 && ain_p->x2 <= aholder_p->x2 &&
         ain_p->y2 <= aholder_p->y2) {
          is_in = true;
      }
  
      return is_in;
  }
  
  /**
   * Increment or decrement an area's size by a single amount
   * @param a_p pointer to an area to grow
   * @param amount amount to increment the area, or negative to decrement
   */
  void lv_area_increment(lv_area_t * a_p, const lv_coord_t amount)
  {
      a_p->x1 -= amount;
      a_p->y1 -= amount;
      a_p->x2 += amount;
      a_p->y2 += amount;
  }
  
  /**********************
   *   STATIC FUNCTIONS
   **********************/
  