Method _applyHalftone

src/tools/texture-lab/renderer.js:1367–1409

(data, width, height, params)

  }

  _applyHalftone(data, width, height, params) {
    const dotSize = params.dotSize;
    const angle = (params.angle * Math.PI) / 180;
    const cos = Math.cos(angle);
    const sin = Math.sin(angle);

    const output = new Uint8ClampedArray(data.length);
    output.fill(255);

    for (let y = 0; y < height; y++) {
      for (let x = 0; x < width; x++) {
        const rx = cos * x - sin * y;
        const ry = sin * x + cos * y;

        const cellX = Math.floor(rx / dotSize) * dotSize + dotSize / 2;
        const cellY = Math.floor(ry / dotSize) * dotSize + dotSize / 2;

        const dist = Math.sqrt(Math.pow(rx - cellX, 2) + Math.pow(ry - cellY, 2));
        const origX = Math.round(cos * cellX + sin * cellY);
        const origY = Math.round(-sin * cellX + cos * cellY);
        const idx = (Math.max(0, Math.min(height - 1, origY)) * width + Math.max(0, Math.min(width - 1, origX))) * 4;

        const brightness = (data[idx] * 0.299 + data[idx + 1] * 0.587 + data[idx + 2] * 0.114) / 255;
        const radius = dotSize * 0.5 * Math.sqrt(brightness);

        const i = (y * width + x) * 4;
        if (dist < radius) {
          if (params.monochrome) {
            output[i] = output[i + 1] = output[i + 2] = 0;
          } else {
            output[i] = data[idx];
            output[i + 1] = data[idx + 1];
            output[i + 2] = data[idx + 2];
          }
        }
        output[i + 3] = 255;
      }
    }

    for (let i = 0; i < data.length; i++) {
      data[i] = output[i];
    }
  }

  _applyAscii(width, height, params) {
    const cellSize = params.cellSize;