@animech-public/playcanvas/build/playcanvas.dbg/src/scene/render.js

PlayCanvas WebGL game engine

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

/**
 * 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.
 *
 * @ignore
 */
class Render extends EventHandler {
  /**
   * Create a new Render instance. These are usually created by the GLB loader and not created
   * by hand.
   */
  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.
     *
     * @type {import('./mesh.js').Mesh[]}
     * @private
     */
    this._meshes = null;
  }

  /**
   * The meshes that the render contains.
   *
   * @type {import('./mesh.js').Mesh[]}
   */
  set meshes(value) {
    // decrement references on the existing meshes
    this.decRefMeshes();

    // assign new meshes
    this._meshes = value;
    this.incRefMeshes();
    this.fire('set:meshes', value);
  }
  get meshes() {
    return this._meshes;
  }
  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.refCount < 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();
        }
      }
    }
  }
}
/**
 * Fired when the meshes are set on the render. The handler is passed the an array of
 * {@link Mesh} objects.
 *
 * @event
 * @example
 * render.on('set:meshes', (meshes) => {
 *     console.log(`Render has ${meshes.length} meshes`);
 * });
 * @ignore
 */
Render.EVENT_SETMESHES = 'set:meshes';

export { Render };