/*
* Copyright 2003-2006, 2009, 2017, United States Government, as represented by the Administrator of the
* National Aeronautics and Space Administration. All rights reserved.
*
* The NASAWorldWind/WebWorldWind platform is licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
define([], function () {
"use strict";
/**
* Provides constants and functions for working with angles.
* @exports Angle
*/
var Angle = {
/**
* Conversion factor for degrees to radians.
* @constant
*/
DEGREES_TO_RADIANS: Math.PI / 180.0,
/**
* Conversion factor for radians to degrees.
* @constant
*/
RADIANS_TO_DEGREES: 180.0 / Math.PI,
/**
* 2 pi.
* @constant
*/
TWO_PI: 2 * Math.PI,
/**
* pi / 2
* @constant
*/
HALF_PI: Math.PI / 2,
/**
* Normalizes a specified value to be within the range of [-180, 180] degrees.
* @param {Number} degrees The value to normalize, in degrees.
* @returns {Number} The specified value normalized to [-180, 180] degrees.
*/
normalizedDegrees: function (degrees) {
var angle = degrees % 360;
return angle > 180 ? angle - 360 : angle < -180 ? 360 + angle : angle;
},
/**
* Normalizes a specified value to be within the range of [-90, 90] degrees.
* @param {Number} degrees The value to normalize, in degrees.
* @returns {Number} The specified value normalized to the normal range of latitude.
*/
normalizedDegreesLatitude: function (degrees) {
var lat = degrees % 180;
return lat > 90 ? 180 - lat : lat < -90 ? -180 - lat : lat;
},
/**
* Normalizes a specified value to be within the range of [-180, 180] degrees.
* @param {Number} degrees The value to normalize, in degrees.
* @returns {Number} The specified value normalized to the normal range of longitude.
*/
normalizedDegreesLongitude: function (degrees) {
var lon = degrees % 360;
return lon > 180 ? lon - 360 : lon < -180 ? 360 + lon : lon;
},
/**
* Normalizes a specified value to be within the range of [-Pi, Pi] radians.
* @param {Number} radians The value to normalize, in radians.
* @returns {Number} The specified value normalized to [-Pi, Pi] radians.
*/
normalizedRadians: function (radians) {
var angle = radians % this.TWO_PI;
return angle > Math.PI ? angle - this.TWO_PI : angle < -Math.PI ? this.TWO_PI + angle : angle;
},
/**
* Normalizes a specified value to be within the range of [-Pi/2, Pi/2] radians.
* @param {Number} radians The value to normalize, in radians.
* @returns {Number} The specified value normalized to the normal range of latitude.
*/
normalizedRadiansLatitude: function (radians) {
var lat = radians % Math.PI;
return lat > this.HALF_PI ? Math.PI - lat : lat < -this.HALF_PI ? -Math.PI - lat : lat;
},
/**
* Normalizes a specified value to be within the range of [-Pi, Pi] radians.
* @param {Number} radians The value to normalize, in radians.
* @returns {Number} The specified value normalized to the normal range of longitude.
*/
normalizedRadiansLongitude: function (radians) {
var lon = radians % this.TWO_PI;
return lon > Math.PI ? lon - this.TWO_PI : lon < -Math.PI ? this.TWO_PI + lon : lon;
},
/**
* Indicates whether a specified value is within the normal range of latitude, [-90, 90].
* @param {Number} degrees The value to test, in degrees.
* @returns {Boolean} true if the value is within the normal range of latitude, otherwise false.
*/
isValidLatitude: function (degrees) {
return degrees >= -90 && degrees <= 90;
},
/**
* Indicates whether a specified value is within the normal range of longitude, [-180, 180].
* @param {Number} degrees The value to test, in degrees.
* @returns {boolean} true if the value is within the normal range of longitude, otherwise false.
*/
isValidLongitude: function (degrees) {
return degrees >= -180 && degrees <= 180;
},
/**
* Returns a string representation of a specified value in degrees.
* @param {Number} degrees The value for which to compute the string.
* @returns {String} The computed string, which is a decimal degrees value followed by the degree symbol.
*/
toString: function (degrees) {
return degrees.toString() + '\u00B0';
},
/**
* Returns a decimal degrees string representation of a specified value in degrees.
* @param {Number} degrees The value for which to compute the string.
* @returns {String} The computed string, which is a decimal degrees value followed by the degree symbol.
*/
toDecimalDegreesString: function (degrees) {
return degrees.toString() + '\u00B0';
},
/**
* Returns a degrees-minutes-seconds string representation of a specified value in degrees.
* @param {Number} degrees The value for which to compute the string.
* @returns {String} The computed string in degrees, minutes and decimal seconds.
*/
toDMSString: function (degrees) {
var sign,
temp,
d,
m,
s;
sign = degrees < 0 ? -1 : 1;
temp = sign * degrees;
d = Math.floor(temp);
temp = (temp - d) * 60;
m = Math.floor(temp);
temp = (temp - m) * 60;
s = Math.round(temp);
if (s == 60) {
m++;
s = 0;
}
if (m == 60) {
d++;
m = 0;
}
return (sign == -1 ? "-" : "") + d + "\u00B0" + " " + m + "\u2019" + " " + s + "\u201D";
},
/**
* Returns a degrees-minutes string representation of a specified value in degrees.
* @param {Number} degrees The value for which to compute the string.
* @returns {String} The computed string in degrees and decimal minutes.
*/
toDMString: function (degrees) {
var sign,
temp,
d,
m,
s,
mf;
sign = degrees < 0 ? -1 : 1;
temp = sign * degrees;
d = Math.floor(temp);
temp = (temp - d) * 60;
m = Math.floor(temp);
temp = (temp - m) * 60;
s = Math.round(temp);
if (s == 60) {
m++;
s = 0;
}
if (m == 60) {
d++;
m = 0;
}
mf = s == 0 ? m : m + s / 60;
return (sign == -1 ? "-" : "") + d + "\u00B0" + " " + mf + "\u2019";
}
};
return Angle;
});