Function createOneTextureLoader

packages/tests/utils.js:310–376

(
  makeTexture: (gl: any) => WebGLTexture,
  size: [number, number]
)

);

export function createOneTextureLoader(
  makeTexture: (gl: any) => WebGLTexture,
  size: [number, number]
) {
  const textureId = Symbol("one-texture");
  const counters = {
    constructor: 0,
    dispose: 0,
    canLoad: 0,
    get: 0,
    load: 0,
    createTexture: 0
  };
  const d = defer();
  function resolve() {
    d.resolve();
    return delay(50); // FIXME this is a hack.
  }
  function reject(e: Error) {
    d.reject(e);
    return delay(50); // FIXME this is a hack.
  }
  class Loader extends WebGLTextureLoader<typeof textureId> {
    texture: ?Texture = null;
    constructor(gl: WebGLRenderingContext) {
      super(gl);
      ++counters.constructor;
    }
    dispose() {
      ++counters.dispose;
    }
    canLoad(input: any) {
      ++counters.canLoad;
      return input === textureId;
    }
    get() {
      ++counters.get;
      return (
        this.texture && {
          texture: this.texture,
          width: size[0],
          height: size[1]
        }
      );
    }
    load() {
      ++counters.load;
      const promise = d.promise.then(() => {
        ++counters.createTexture;
        this.texture = makeTexture(this.gl);
        return {
          texture: this.texture,
          width: size[0],
          height: size[1]
        };
      });
      return promise;
    }