Babylon.js/src/Particles/babylon.particleSystemSet.ts

module BABYLON {

    /** Internal class used to store shapes for emitters */
    class ParticleSystemSetEmitterCreationOptions {
        public kind: string;
        public options: any;
        public renderingGroupId: number;
    }

    /**
     * Represents a set of particle systems working together to create a specific effect
     */
    export class ParticleSystemSet implements IDisposable {
        private _emitterCreationOptions: ParticleSystemSetEmitterCreationOptions;
        private _emitterNode: Nullable<TransformNode>;

        /**
         * Gets the particle system list
         */
        public systems = new Array<IParticleSystem>();

        /**
         * Gets the emitter node used with this set
         */
        public get emitterNode(): Nullable<TransformNode> {
            return this._emitterNode;
        }

        /**
         * Creates a new emitter mesh as a sphere
         * @param options defines the options used to create the sphere
         * @param renderingGroupId defines the renderingGroupId to use for the sphere
         * @param scene defines the hosting scene
         */
        public setEmitterAsSphere(options: {diameter: number, segments: number, color: Color3} , renderingGroupId: number, scene: Scene) {
            if (this._emitterNode) {
                this._emitterNode.dispose();
            }

            this._emitterCreationOptions = {
                kind: "Sphere",
                options: options,
                renderingGroupId: renderingGroupId
            }

            let emitterMesh = MeshBuilder.CreateSphere("emitterSphere", {diameter: options.diameter, segments: options.segments}, scene);
            emitterMesh.renderingGroupId = renderingGroupId;

            var material = new BABYLON.StandardMaterial("emitterSphereMaterial", scene)
            material.emissiveColor = options.color;    
            emitterMesh.material = material;     
            
            for (var system of this.systems) {
                system.emitter = emitterMesh;
            }

            this._emitterNode = emitterMesh;
        }

        /**
         * Starts all particle systems of the set
         * @param emitter defines an optional mesh to use as emitter for the particle systems
         */
        public start(emitter?: AbstractMesh): void {
            for (var system of this.systems) {
                if (emitter) {
                    system.emitter = emitter;
                }
                system.start();
            }
        }

        /**
         * Release all associated resources
         */
        public dispose(): void {
            for (var system of this.systems) {
                system.dispose();
            }

            this.systems = [];

            if (this._emitterNode) {
                this._emitterNode.dispose();
                this._emitterNode = null;
            }
        }

        /**
         * Serialize the set into a JSON compatible object
         * @returns a JSON compatible representation of the set
         */
        public serialize(): any {
            var result:any = {};

            result.systems = [];
            for (var system of this.systems) {
                result.systems.push(system.serialize());
            }

            if (this._emitterNode) {
                result.emitter = this._emitterCreationOptions;
            }

            return result;
        }

        /** 
         * Parse a new ParticleSystemSet from a serialized source
         * @param data defines a JSON compatible representation of the set
         * @param scene defines the hosting scene
         * @param gpu defines if we want GPU particles or CPU particles
         * @returns a new ParticleSystemSet
         */
        public static Parse(data: any, scene: Scene, gpu = false): ParticleSystemSet {
            var result = new ParticleSystemSet();
            var rootUrl = ParticleHelper.BaseAssetsUrl + "/textures/";

            for (var system of data.systems) {
                result.systems.push(gpu ? GPUParticleSystem.Parse(system, scene, rootUrl) : ParticleSystem.Parse(system, scene, rootUrl));
            }

            if (data.emitter) {
                let options = data.emitter.options;
                switch (data.emitter.kind) {                    
                    case "Sphere":
                        result.setEmitterAsSphere({
                            diameter: options.diameter, 
                            segments: options.segments,
                            color: Color3.FromArray(options.color)
                        }, data.emitter.renderingGroupId, scene);
                        break;
                }
            }

            return result;
        }
    }
}