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......image.toPixelData().forEach((pixel, index) => {  if (pixel.alpha <= 0) {    this._filledSet.add(index);  }});......

/**     * Creates a texture from the specified image.     *     * You must call this function while the engine is running     * ([[Window.running]] is `true`), otherwise it will return null.     *     * @export     * @param {Image} image An image.     * @param {(Sampler | null)} [sampler] An object that defines how a texture     * should be sampled.     * @returns {(Texture | null)} A new texture object.     */    export function createFromImage(      image: Image,      sampler?: Sampler | null    ): Texture | null;

void main() {  float alpha = min(texture2D(u_texture, v_tex_coord).a, 0.4);  gl_FragColor = alpha * vec4(0.0, 0.0, 0.0, 1.0);}

protected isAvailable(minCol: number, minRow: number, maxCol: number, maxRow: number): boolean {    if (minCol > maxCol || minRow > maxRow) {      return true;    }    for (let col = minCol; col <= maxCol; col++) {      if (        this._filledSet.has(this.positionToIndex(col, minRow)) ||        this._filledSet.has(this.positionToIndex(col, maxRow))      ) {        return false;      }    }    for (let row = minRow; row <= maxRow; row++) {      if (        this._filledSet.has(this.positionToIndex(minCol, row)) ||        this._filledSet.has(this.positionToIndex(maxCol, row))      ) {        return false;      }    }    return this.isAvailable(minCol + 1, minRow + 1, maxCol - 1, maxRow - 1);  }

......const pixelCount = this.pixelCount;this._filledArray = new Uint8Array(pixelCount);this._integralPixelArray = new Uint32Array(pixelCount);for (let col = 0; col < this._width; col++) {  for (let row = 0; row < this._height; row++) {    const index = this.positionToIndex(col, row);    this._filledArray[index] = this._colorArray[index][3] > 0 ? 0 : 1;    this._integralPixelArray[index] = this._filledArray[index];    if (col > 0) {      this._integralPixelArray[index] += this._integralPixelArray[this.positionToIndex(col - 1, row)];    }    if (row > 0) {      this._integralPixelArray[index] += this._integralPixelArray[this.positionToIndex(col, row - 1)];    }    if (col > 0 && row > 0) {      this._integralPixelArray[index] -= this._integralPixelArray[this.positionToIndex(col - 1, row - 1)];    }  }}......

protected isAvailable(minCol: number, minRow: number, maxCol: number, maxRow: number): boolean {    const totalPixelCount = this._integralPixelArray[this.positionToIndex(maxCol, maxRow)];    const topPixelCount = minRow <= 0 ? 0 : this._integralPixelArray[this.positionToIndex(maxCol, minRow - 1)];    const leftPixelCount = minCol <= 0 ? 0 : this._integralPixelArray[this.positionToIndex(minCol - 1, maxRow)];    const leftTopPixelCount =      minRow <= 0 || minCol <= 0 ? 0 : this._integralPixelArray[this.positionToIndex(minCol - 1, minRow - 1)];    return totalPixelCount - topPixelCount - leftPixelCount + leftTopPixelCount <= 0;  }}

function createRectSpiralGenerator(  width: number,  height: number,  dt: number): (t: number, offset: number) => Position {  let x = 0;  let y = 0;  return function (t: number, offset: number = 0) {    t = t + offset;    const sign = t < 0 ? -1 : 1;    const num = Math.ceil(Math.sqrt(1 + 4 * t * sign) - sign) & 3;    if (num === 0) {      x += dt;    } else if (num === 1) {      y += dt;    } else if (num === 2) {      x -= dt;    } else {      y -= dt;    }    return {      col: x + Math.floor(width / 2),      row: y + Math.floor(height / 2),    };  };}

......const generator = createRectSpiralGenerator(this._width, this._height, spiralDelta);let t = 0;while (true) {  t += 1;  const pos = generator(t, 0);  if ((pos.col < 0 || pos.col >= this._width) && (pos.row < 0 || pos.row >= this._height)) {    break;  }  if (pos.col < 0 || pos.col >= this._width || pos.row < 0 || pos.row >= this._height) {    continue;  }  const index = this.positionToIndex(pos.col, pos.row);  if (this._colorArray[index][3] <= 0) {    continue;  }  this._availableIndexSet.add(index);}......

......App.getTaskWorkerBinder()?.sendMsg(  Task.WORD_CLOUD_UPDATE,  {    timeout, count  },  (response, expired) => {    const textureKey: string | null = response.key ?? null;    if (expired) {      cron.TransferCenter.instance.popObjectForKey(textureKey)?.release();      return;    }    const count: number = response.count ?? 0;    const completed: boolean = response.completed ?? false;    const success: boolean = response.success ?? false;    if (completed) {      this.reportShowEventIfNeeded(success, count);    } else {      this.triggerWordCloudEngineUpdate();    }    const texture = cron.TransferCenter.instance.popObjectForKey(textureKey);    this._displayer.addOneGroup(texture, completed, success);    texture.release();  });......

......const timeout = request.timeout;const count = request.count;const results = wordCloudEngine.run(timeout, count);const img = wordCloudEngine.snapshot(results);const texture = cron.Texture.createFromImage(img);const key = `word_cloud_${token++}`;cron.TransferCenter.instance.pushObjectForKey(key, texture);texture.release();response.key = key;response.completed = wordCloudEngine.completed;response.success = wordCloudEngine.filledRatio >= DEFAULT_FILLED_RATIO;response.count = wordCloudEngine.results.length;......

run(timeout: number = Number.POSITIVE_INFINITY, count?: number): Result<T>[] {  const results: Result<T>[] = [];  const ts = Date.now();  while (!this.completed && Date.now() - ts < timeout) {    const result = this.runOnce();    if (result) {      results.push(result);      if (count <= results.length) {        break;      }    }  }  return results;}

runOnce(): Result<T> | null {  if (this.completed) {    return null;  }  const model = this._models.next();  const style = this.findAvailable(model);  if (!style) {    return null;  }  const result = {    model,    style,  };  this._results.push(result);  return result;}