Function getMeterPerMapUnit

src/common/util/MapCalculateUtil.js:25–45

(mapUnit)

 * ```
 */
export var getMeterPerMapUnit = function(mapUnit) {
    var meterPerMapUnit;
    if(!mapUnit){
      return meterPerMapUnit;
    }
    var earchRadiusInMeters = 6378137;
    
    if (['m','meter','meters'].indexOf(mapUnit.toLocaleLowerCase())>-1) {
        meterPerMapUnit = 1;
    } else if (['degrees','deg','degree','dd'].indexOf(mapUnit.toLocaleLowerCase())>-1) {
        // 每度表示多少米。
        meterPerMapUnit = (Math.PI * 2 * earchRadiusInMeters) / 360;
    } else if (mapUnit === Unit.KILOMETER) {
        meterPerMapUnit = 1000;
    } else if (mapUnit === Unit.INCH) {
        meterPerMapUnit = 2.5399999918e-2;
    } else if (mapUnit === Unit.FOOT) {
        meterPerMapUnit = 0.3048;
    }
    return meterPerMapUnit;
};

/**
 * @private