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