webgl-3d-viewer/src/viewer/loaders/ModelLoaderRegistry.js

A WebGL ThreeJS STL viewer implementation written in ES6

import ldFirst from 'lodash/array/first';
import ldFilter from 'lodash/collection/filter';
import md5 from 'blueimp-md5';

import Loader from './STLLoader';


export default class ModelLoaderRegistry {

  get registry() {
    return ModelLoaderRegistry.modelRegistry;
  }

  load(url, onLoad = ()=>{}, onProgress = ()=>{}, onError = ()=>{}, onParseStart = ()=>{}, onParseEnd = ()=>{}) {

    const id = this._genId(url);
    const regEntry = this._findEntryById(id);

    if (regEntry) {
      let geometry = regEntry.geometry;
      geometry.registry = true;

      onParseStart();
      onLoad(regEntry.geometry);
      onParseEnd();
      onProgress({loaded: 100, total: 100});
    } else {

      const loader = new Loader();

      loader.load(url, (geometry) => {

        geometry.registry = false;

        const RegistryItem = {
          id: id,
          geometry: geometry
        };

        this.registry.push(RegistryItem);
        onLoad(geometry);

      }, onProgress, onError, onParseStart, onParseEnd);
    }
  }

  parse(model) {

    const id = this._genId(model);
    const regEntry = this._findEntryById(id);
    let geometry = null;

    if (regEntry) {
      geometry = regEntry.geometry;
      geometry.registry = true;
    } else {

      const loader = new Loader();
      const content = loader.parse(model);

      const RegistryItem = {
        id: id,
        geometry: content
      };

      this.registry.push(RegistryItem);
      geometry = content;
      geometry.registry = true;
    }

    return geometry;
  }

  _findEntryById(id) {
    const entry = ldFirst(ldFilter(this.registry, {id: id}));

    if (entry) {
      return Object.assign({}, entry);
    }
  }

  _genId(base) {

    let id = '';

    if (base instanceof ArrayBuffer) {
      // ConvertBufferToBase64
      const bufferBase64 = btoa([].reduce.call(new Uint8Array(base), function(p, c) { return p + String.fromCharCode(c); }, ''));
      id = md5(bufferBase64, 'arraybuffer');
    } else {
      id =  md5(base, 'url');
    }

    return id;
  }
}

ModelLoaderRegistry.modelRegistry = [];