Add existing to tracked

node_modules/@cesium/engine/Source/Scene/ConeEmitter.js

@@ -0,0 +1,61 @@
+import Cartesian3 from "../Core/Cartesian3.js";
+import Check from "../Core/Check.js";
+import CesiumMath from "../Core/Math.js";
+
+const defaultAngle = CesiumMath.toRadians(30.0);
+
+/**
+ * A ParticleEmitter that emits particles within a cone.
+ * Particles will be positioned at the tip of the cone and have initial velocities going towards the base.
+ *
+ * @alias ConeEmitter
+ * @constructor
+ *
+ * @param {number} [angle=Cesium.Math.toRadians(30.0)] The angle of the cone in radians.
+ */
+function ConeEmitter(angle) {
+  this._angle = angle ?? defaultAngle;
+}
+
+Object.defineProperties(ConeEmitter.prototype, {
+  /**
+   * The angle of the cone in radians.
+   * @memberof CircleEmitter.prototype
+   * @type {number}
+   * @default Cesium.Math.toRadians(30.0)
+   */
+  angle: {
+    get: function () {
+      return this._angle;
+    },
+    set: function (value) {
+      //>>includeStart('debug', pragmas.debug);
+      Check.typeOf.number("value", value);
+      //>>includeEnd('debug');
+      this._angle = value;
+    },
+  },
+});
+
+/**
+ * Initializes the given {Particle} by setting it's position and velocity.
+ *
+ * @private
+ * @param {Particle} particle The particle to initialize
+ */
+ConeEmitter.prototype.emit = function (particle) {
+  const radius = Math.tan(this._angle);
+
+  // Compute a random point on the cone's base
+  const theta = CesiumMath.randomBetween(0.0, CesiumMath.TWO_PI);
+  const rad = CesiumMath.randomBetween(0.0, radius);
+
+  const x = rad * Math.cos(theta);
+  const y = rad * Math.sin(theta);
+  const z = 1.0;
+
+  particle.velocity = Cartesian3.fromElements(x, y, z, particle.velocity);
+  Cartesian3.normalize(particle.velocity, particle.velocity);
+  particle.position = Cartesian3.clone(Cartesian3.ZERO, particle.position);
+};
+export default ConeEmitter;