Babylon.js/src/Particles/subEmitter.ts

import { Vector3 } from "Maths/math";
import { AbstractMesh } from "Meshes/abstractMesh";
import { Mesh } from "Meshes/mesh";
import { ParticleSystem } from "Particles/particleSystem";
import { Scene } from "scene";
    /**
     * Type of sub emitter
     */
    export enum SubEmitterType {
        /**
         * Attached to the particle over it's lifetime
         */
        ATTACHED,
        /**
         * Created when the particle dies
         */
        END
    }

    /**
     * Sub emitter class used to emit particles from an existing particle
     */
    export class SubEmitter {
        /**
         * Type of the submitter (Default: END)
         */
        public type = SubEmitterType.END;
        /**
         * If the particle should inherit the direction from the particle it's attached to. (+Y will face the direction the particle is moving) (Default: false)
         * Note: This only is supported when using an emitter of type Mesh
         */
        public inheritDirection = false;
        /**
         * How much of the attached particles speed should be added to the sub emitted particle (default: 0)
         */
        public inheritedVelocityAmount = 0;
        /**
         * Creates a sub emitter
         * @param particleSystem the particle system to be used by the sub emitter
         */
        constructor(
            /**
             * the particle system to be used by the sub emitter
             */
            public particleSystem: ParticleSystem
        ) {
            // Create mesh as emitter to support rotation
            if (!particleSystem.emitter || !(<AbstractMesh>particleSystem.emitter).dispose) {
                particleSystem.emitter = new AbstractMesh("SubemitterSystemEmitter", particleSystem.getScene());
            }

            // Automatically dispose of subemitter when system is disposed
            particleSystem.onDisposeObservable.add(() => {
                if (particleSystem.emitter && (<AbstractMesh>particleSystem.emitter).dispose) {
                    (<AbstractMesh>particleSystem.emitter).dispose();
                }
            });
        }
        /**
         * Clones the sub emitter
         * @returns the cloned sub emitter
         */
        public clone(): SubEmitter {
            // Clone particle system
            var emitter = this.particleSystem.emitter;
            if (!emitter) {
                emitter = new Vector3();
            } else if (emitter instanceof Vector3) {
                emitter = emitter.clone();
            } else if (emitter instanceof AbstractMesh) {
                emitter = new Mesh("", emitter.getScene());
                emitter.isVisible = false;
            }
            var clone = new SubEmitter(this.particleSystem.clone("", emitter));

            // Clone properties
            clone.type = this.type;
            clone.inheritDirection = this.inheritDirection;
            clone.inheritedVelocityAmount = this.inheritedVelocityAmount;

            clone.particleSystem._disposeEmitterOnDispose = true;
            clone.particleSystem.disposeOnStop = true;
            return clone;
        }

        /**
         * Serialize current object to a JSON object
         * @returns the serialized object
         */
        public serialize(): any {
            let serializationObject: any = {};

            serializationObject.type = this.type;
            serializationObject.inheritDirection = this.inheritDirection;
            serializationObject.inheritedVelocityAmount = this.inheritedVelocityAmount;
            serializationObject.particleSystem = this.particleSystem.serialize();

            return serializationObject;
        }

        /**
         * Creates a new SubEmitter from a serialized JSON version
         * @param serializationObject defines the JSON object to read from
         * @param scene defines the hosting scene
         * @param rootUrl defines the rootUrl for data loading
         * @returns a new SubEmitter
         */
        public static Parse(serializationObject: any, scene: Scene, rootUrl: string): SubEmitter {
            let system = serializationObject.particleSystem;
            let subEmitter = new SubEmitter(ParticleSystem.Parse(system, scene, rootUrl));
            subEmitter.type = serializationObject.type;
            subEmitter.inheritDirection = serializationObject.inheritDirection;
            subEmitter.inheritedVelocityAmount = serializationObject.inheritedVelocityAmount;
            subEmitter.particleSystem._isSubEmitter = true;

            return subEmitter;
        }

        /** Release associated resources */
        public dispose() {
            this.particleSystem.dispose();
        }
    }