import { EventHandler } from '../core/event-handler.js';

/**

* @event

* @private

* @name Render#set:meshes

* @description Fired when the meshes are set

* @param {Mesh[]} meshes - The meshes

*/

/**

* @class

* @private

* @name Render

* @augments EventHandler

* @classdesc A render contains an array of meshes that are referenced by a single hierarchy node in a GLB model, and are accessible using {@link ContainerResource#renders} property. The render is the resource of a Render Asset.

* @description Create a new Render. These are usually created by the GLB loader and not created by hand.

* @property {Mesh[]} meshes The meshes that the render contains

*/

class Render extends EventHandler {

constructor() {

super();

// meshes are reference counted, and this class owns the references and is responsible

// for releasing the meshes when they are no longer referenced

this._meshes = null;

}

destroy() {

this.meshes = null;

}

// decrement references to meshes, destroy the ones with zero references

decRefMeshes() {

if (this._meshes) {

const count = this._meshes.length;

for (let i = 0; i < count; i++) {

const mesh = this._meshes[i];

if (mesh) {

mesh.decRefCount();

if (mesh.getRefCount() < 1) {

mesh.destroy();

this._meshes[i] = null;

}

}

}

}

}

// increments ref count on all meshes

incRefMeshes() {

if (this._meshes) {

const count = this._meshes.length;

for (let i = 0; i < count; i++) {

if (this._meshes[i]) {

this._meshes[i].incRefCount();

}

}

}

}

get meshes() {

return this._meshes;

}

set meshes(value) {

// decrement references on the existing meshes

this.decRefMeshes();

// assign new meshes

this._meshes = value;

this.incRefMeshes();

this.fire('set:meshes', value);

}

}

export { Render };