@openhps/core/dist/esm/three/loaders/CompressedTextureLoader.js

Open Hybrid Positioning System - Core component

import { LinearFilter } from '../constants.js';
import { FileLoader } from './FileLoader.js';
import { CompressedTexture } from '../textures/CompressedTexture.js';
import { Loader } from './Loader.js';

/**
 * Abstract base class for loading compressed texture formats S3TC, ASTC or ETC.
 * Textures are internally loaded via {@link FileLoader}.
 *
 * Derived classes have to implement the `parse()` method which holds the parsing
 * for the respective format.
 *
 * @abstract
 * @augments Loader
 */
class CompressedTextureLoader extends Loader {
  /**
   * Constructs a new compressed texture loader.
   *
   * @param {LoadingManager} [manager] - The loading manager.
   */
  constructor(manager) {
    super(manager);
  }

  /**
   * Starts loading from the given URL and passes the loaded compressed texture
   * to the `onLoad()` callback. The method also returns a new texture object which can
   * directly be used for material creation. If you do it this way, the texture
   * may pop up in your scene once the respective loading process is finished.
   *
   * @param {string} url - The path/URL of the file to be loaded. This can also be a data URI.
   * @param {function(CompressedTexture)} onLoad - Executed when the loading process has been finished.
   * @param {onProgressCallback} onProgress - Executed while the loading is in progress.
   * @param {onErrorCallback} onError - Executed when errors occur.
   * @return {CompressedTexture} The compressed texture.
   */
  load(url, onLoad, onProgress, onError) {
    const scope = this;
    const images = [];
    const texture = new CompressedTexture();
    const loader = new FileLoader(this.manager);
    loader.setPath(this.path);
    loader.setResponseType('arraybuffer');
    loader.setRequestHeader(this.requestHeader);
    loader.setWithCredentials(scope.withCredentials);
    let loaded = 0;
    function loadTexture(i) {
      loader.load(url[i], function (buffer) {
        const texDatas = scope.parse(buffer, true);
        images[i] = {
          width: texDatas.width,
          height: texDatas.height,
          format: texDatas.format,
          mipmaps: texDatas.mipmaps
        };
        loaded += 1;
        if (loaded === 6) {
          if (texDatas.mipmapCount === 1) texture.minFilter = LinearFilter;
          texture.image = images;
          texture.format = texDatas.format;
          texture.needsUpdate = true;
          if (onLoad) onLoad(texture);
        }
      }, onProgress, onError);
    }
    if (Array.isArray(url)) {
      for (let i = 0, il = url.length; i < il; ++i) {
        loadTexture(i);
      }
    } else {
      // compressed cubemap texture stored in a single DDS file

      loader.load(url, function (buffer) {
        const texDatas = scope.parse(buffer, true);
        if (texDatas.isCubemap) {
          const faces = texDatas.mipmaps.length / texDatas.mipmapCount;
          for (let f = 0; f < faces; f++) {
            images[f] = {
              mipmaps: []
            };
            for (let i = 0; i < texDatas.mipmapCount; i++) {
              images[f].mipmaps.push(texDatas.mipmaps[f * texDatas.mipmapCount + i]);
              images[f].format = texDatas.format;
              images[f].width = texDatas.width;
              images[f].height = texDatas.height;
            }
          }
          texture.image = images;
        } else {
          texture.image.width = texDatas.width;
          texture.image.height = texDatas.height;
          texture.mipmaps = texDatas.mipmaps;
        }
        if (texDatas.mipmapCount === 1) {
          texture.minFilter = LinearFilter;
        }
        texture.format = texDatas.format;
        texture.needsUpdate = true;
        if (onLoad) onLoad(texture);
      }, onProgress, onError);
    }
    return texture;
  }
}

/**
 * Represents the result object type of the `parse()` method.
 *
 * @typedef {Object} CompressedTextureLoader~TexData
 * @property {number} width - The width of the base mip.
 * @property {number} height - The width of the base mip.
 * @property {boolean} isCubemap - Whether the data represent a cubemap or not.
 * @property {number} mipmapCount - The mipmap count.
 * @property {Array<{data:TypedArray,width:number,height:number}>} mipmaps - An array holding the mipmaps.
 * Each entry holds the data and the dimensions for each level.
 * @property {number} format - The texture format.
 **/

export { CompressedTextureLoader };