/*
* 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.
*/
/**
* @exports SurfaceCircle
*/
define(['../error/ArgumentError',
'../geom/Location',
'../util/Logger',
'../shapes/ShapeAttributes',
'../shapes/SurfaceShape'
],
function (ArgumentError,
Location,
Logger,
ShapeAttributes,
SurfaceShape) {
"use strict";
/**
* Constructs a surface circle with a specified center and radius and an optional attributes bundle.
* @alias SurfaceCircle
* @constructor
* @augments SurfaceShape
* @classdesc Represents a circle draped over the terrain surface.
* <p>
* SurfaceCircle uses the following attributes from its associated shape attributes bundle:
* <ul>
* <li>Draw interior</li>
* <li>Draw outline</li>
* <li>Interior color</li>
* <li>Outline color</li>
* <li>Outline width</li>
* <li>Outline stipple factor</li>
* <li>Outline stipple pattern</li>
* </ul>
* @param {Location} center The circle's center location.
* @param {Number} radius The circle's radius in meters.
* @param {ShapeAttributes} attributes The attributes to apply to this shape. May be null, in which case
* attributes must be set directly before the shape is drawn.
* @throws {ArgumentError} If the specified center location is null or undefined or the specified radius
* is negative.
*/
var SurfaceCircle = function (center, radius, attributes) {
if (!center) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "SurfaceCircle", "constructor", "missingLocation"));
}
if (radius < 0) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "SurfaceCircle", "constructor", "Radius is negative"));
}
SurfaceShape.call(this, attributes);
// All these are documented with their property accessors below.
this._center = center;
this._radius = radius;
this._intervals = SurfaceCircle.DEFAULT_NUM_INTERVALS;
};
SurfaceCircle.prototype = Object.create(SurfaceShape.prototype);
Object.defineProperties(SurfaceCircle.prototype, {
/**
* This shape's center location.
* @memberof SurfaceCircle.prototype
* @type {Location}
*/
center: {
get: function () {
return this._center;
},
set: function (value) {
this.stateKeyInvalid = true;
this.resetBoundaries();
this._center = value;
}
},
/**
* This shape's radius, in meters.
* @memberof SurfaceCircle.prototype
* @type {Number}
*/
radius: {
get: function () {
return this._radius;
},
set: function (value) {
this.stateKeyInvalid = true;
this.resetBoundaries();
this._radius = value;
}
},
/**
* The number of intervals to generate locations for.
* @type {Number}
* @memberof SurfaceCircle.prototype
* @default SurfaceCircle.DEFAULT_NUM_INTERVALS
*/
intervals: {
get: function () {
return this._intervals;
},
set: function (value) {
this.stateKeyInvalid = true;
this.resetBoundaries();
this._intervals = value;
}
}
});
// Internal use only. Intentionally not documented.
SurfaceCircle.staticStateKey = function (shape) {
var shapeStateKey = SurfaceShape.staticStateKey(shape);
return shapeStateKey +
" ce " + shape.center.toString() +
" ra " + shape.radius.toString();
};
// Internal use only. Intentionally not documented.
SurfaceCircle.prototype.computeStateKey = function () {
return SurfaceCircle.staticStateKey(this);
};
// Internal. Intentionally not documented.
SurfaceCircle.prototype.computeBoundaries = function (dc) {
if (this.radius === 0) {
return null;
}
var numLocations = 1 + Math.max(SurfaceCircle.MIN_NUM_INTERVALS, this.intervals),
da = 360 / (numLocations - 1),
arcLength = this.radius / dc.globe.radiusAt(this.center.latitude, this.center.longitude);
this._boundaries = new Array(numLocations);
for (var i = 0; i < numLocations; i++) {
var azimuth = (i !== numLocations - 1) ? (i * da) : 0;
this._boundaries[i] = Location.greatCircleLocation(
this.center,
azimuth, // In degrees
arcLength, // In radians
new Location(0, 0)
);
}
};
// Internal use only. Intentionally not documented.
SurfaceCircle.prototype.getReferencePosition = function () {
return this.center;
};
// Internal use only. Intentionally not documented.
SurfaceCircle.prototype.moveTo = function (globe, position) {
this.center = position;
};
/**
* The minimum number of intervals the circle generates.
* @type {Number}
*/
SurfaceCircle.MIN_NUM_INTERVALS = 8;
/**
* The default number of intervals the circle generates.
* @type {Number}
*/
SurfaceCircle.DEFAULT_NUM_INTERVALS = 64;
return SurfaceCircle;
});