74 lines
2.1 KiB
JavaScript
74 lines
2.1 KiB
JavaScript
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define([
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'../Core/Cartesian3',
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'../Core/Check',
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'../Core/defaultValue',
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'../Core/defineProperties',
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'../Core/Math'
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], function(
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Cartesian3,
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Check,
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defaultValue,
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defineProperties,
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CesiumMath) {
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'use strict';
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/**
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* A ParticleEmitter that emits particles from a circle.
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* Particles will be positioned within a circle and have initial velocities going along the z vector.
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*
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* @alias CircleEmitter
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* @constructor
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*
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* @param {Number} [radius=1.0] The radius of the circle in meters.
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*/
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function CircleEmitter(radius) {
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radius = defaultValue(radius, 1.0);
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//>>includeStart('debug', pragmas.debug);
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Check.typeOf.number.greaterThan('radius', radius, 0.0);
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//>>includeEnd('debug');
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this._radius = defaultValue(radius, 1.0);
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}
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defineProperties(CircleEmitter.prototype, {
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/**
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* The radius of the circle in meters.
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* @memberof CircleEmitter.prototype
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* @type {Number}
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* @default 1.0
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*/
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radius : {
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get : function() {
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return this._radius;
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},
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set : function(value) {
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//>>includeStart('debug', pragmas.debug);
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Check.typeOf.number.greaterThan('value', value, 0.0);
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//>>includeEnd('debug');
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this._radius = value;
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}
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}
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});
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/**
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* Initializes the given {@link Particle} by setting it's position and velocity.
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*
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* @private
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* @param {Particle} particle The particle to initialize.
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*/
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CircleEmitter.prototype.emit = function(particle) {
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var theta = CesiumMath.randomBetween(0.0, CesiumMath.TWO_PI);
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var rad = CesiumMath.randomBetween(0.0, this._radius);
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var x = rad * Math.cos(theta);
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var y = rad * Math.sin(theta);
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var z = 0.0;
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particle.position = Cartesian3.fromElements(x, y, z, particle.position);
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particle.velocity = Cartesian3.clone(Cartesian3.UNIT_Z, particle.velocity);
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};
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return CircleEmitter;
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});
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