Function drawOledThresholdedImage

app.js:3645–3679

(ctx, src, x, y, w, h, color)

}

function drawOledThresholdedImage(ctx, src, x, y, w, h, color) {
  const img = getCachedOledImage(src);
  if (!img || !img.complete || !img.naturalWidth) return;
  const W = Math.max(1, Math.floor(w));
  const H = Math.max(1, Math.floor(h));
  imgCanvas.width = W;
  imgCanvas.height = H;
  imgCtx.clearRect(0, 0, W, H);
  imgCtx.imageSmoothingEnabled = false;
  imgCtx.drawImage(img, 0, 0, W, H);
  let data = null;
  try {
    data = imgCtx.getImageData(0, 0, W, H).data;
  } catch (e) {
    // Likely a CORS/file:// tainted canvas. Fallback: draw pixelated image without thresholding.
    try {
      ctx.imageSmoothingEnabled = false;
      ctx.drawImage(img, x, y, W, H);
      return;
    } catch (_) {
      return;
    }
  }
  ctx.fillStyle = color;
  for (let j = 0; j < H; j++) {
    for (let i = 0; i < W; i++) {
      const idx = (j * W + i) * 4;
      const a = data[idx + 3];
      if (a < 50) continue;
      const r = data[idx], g = data[idx + 1], b = data[idx + 2];
      const lum = (0.299 * r + 0.587 * g + 0.114 * b);
      if (lum > 80) ctx.fillRect(x + i, y + j, 1, 1);
    }
  }
}

function renderElements() {
  const scale = parseFloat(preview.dataset.scale || "1");