地图金字塔所在块的经纬度范围 算法

地图金字塔从第0层开始

#define LON_SPAN 360.0
// 开始经度(最左端)
#define LAT_SPAN 180.0
#define GLOBAL_LEFT -180.0
// 开始纬度(最上端)
#define GLOBAL_TOP 90.0
#define GLOBAL_RIGHT 180.0
#define GLOBAL_BOTTOM -90.0
// 地球的纬度跨度(180-(-180)):360
#define LON_SPAN (GLOBAL_RIGHT - GLOBAL_LEFT)
// 地球的纬度跨度(90-(-90)):180
#define LAT_SPAN (GLOBAL_TOP - GLOBAL_BOTTOM)/// <summary>/// 给出块所在的层行列，求该块的经纬范围/// </summary>/// <param name="x">块所在的列</param>/// <param name="y">块所在的行</param>/// <param name="z">层数(start from 0)</param>void block_lat_and_lon_range(int storey, int block_x, int block_y, float& block_left, float& block_right, float& block_top, float& block_bottom){// 得到该块的经纬度坐标边界int n = pow(2, storey);// 经度float tile_width = LON_SPAN / n; // 每块的纬度跨度block_left = GLOBAL_LEFT + (block_y * tile_width);block_right = GLOBAL_LEFT + ((block_y + 1) * tile_width);// 纬度float tile_height = LAT_SPAN / n; // 每块的经度跨度block_top = GLOBAL_TOP - (block_x * tile_height);block_bottom = GLOBAL_TOP - ((block_x + 1) * tile_height);}