/**
 * The maximum latitude, in radians, 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 as follows:
 *   czm_pi * 0.5 - (2.0 * atan(exp(-czm_pi)))
 *
 * @name czm_webMercatorMaxLatitude
 * @glslConstant
 */
const float czm_webMercatorMaxLatitude = 1.4844222297453324;