Add progress information about wasm-vips HOT 3 CLOSED

// Load a huge image
const im = vips.Image.black(100000, 100000);

// Attach progress feedback
let lastPercent = 0;
im.onProgress = (percent) => {
  // This callback is triggered once per work unit (typically a 128 x
  // 128 area of pixels) during image computation. Therefore, we only
  // need to print when there's a change in the percentage.
  if (percent !== lastPercent) {
    console.log(`${percent}% complete`);
    lastPercent = percent;
  }

  // To stop long-running computations, we could block evaluation after a
  // certain amount of time. To avoid complexity in this example, issue the
  // kill signal after 25% completion.
  if (percent >= 25) {
    im.kill = true;
  }
};

// Save
im.writeToFile('x.png');