WebMercatorProjection

Web 墨卡托 (EPSG:3857) 投影支持的最大纬度（北纬和南纬）。从技术上讲，墨卡托投影是针对 90 度以内（但不包括）的任何纬度定义的，但尽早切断它是有意义的，因为它随着纬度的增加呈指数增长。 Google 地图、Bing 地图和 Esri 使用的这一特定截止值背后的逻辑是，它使投影成为正方形。即，矩形在X和Y方向上相等。常量值通过调用计算：WebMercatorProjection.mercatorAngleToGeodeticLatitude(Math.PI) The maximum latitude (both North and South) supported by a Web Mercator (EPSG:3857) projection. Technically, the Mercator projection is defined for any latitude up to (but not including) 90 degrees, but it makes sense to cut it off sooner because it grows exponentially with increasing latitude. The logic behind this particular cutoff value, which is the one used by Google Maps, Bing Maps, and Esri, is that it makes the projection square. That is, the rectangle is equal in the X and Y directions. The constant value is computed by calling: WebMercatorProjection.mercatorAngleToGeodeticLatitude(Math.PI)

得到 Gets the Ellipsoid.

将 -PI/2 到 PI/2 范围内的以弧度表示的大地纬度转换为 -PI 到 PI 范围内的墨卡托角。 Converts a geodetic latitude in radians, in the range -PI/2 to PI/2, to a Mercator angle in the range -PI to PI.

将 -PI 到 PI 范围内的墨卡托角转换为 -PI/2 到 PI/2 范围内的大地纬度。 Converts a Mercator angle, in the range -PI to PI, to a geodetic latitude in the range -PI/2 to PI/2.

将大地椭球坐标（以弧度为单位）转换为以米为单位的等效 Web 墨卡托 X、Y、Z 坐标并以 a 形式返回 Converts geodetic ellipsoid coordinates, in radians, to the equivalent Web Mercator X, Y, Z coordinates expressed in meters and returned in a Cartesian3。高度将不加修改地复制到 Z 坐标。 . The height is copied unmodified to the Z coordinate.

将 Web 墨卡托 X、Y 坐标（以米为单位）转换为 Converts Web Mercator X, Y coordinates, expressed in meters, to a Cartographic 包含大地椭球坐标。 Z 坐标不加修改地复制到高度。 containing geodetic ellipsoid coordinates. The Z coordinate is copied unmodified to the height.