// src/workers/renderer.worker.js

// Color gradients
const viridis = [
  [68, 1, 84], [68, 2, 86], [69, 4, 87], [69, 5, 89], [70, 7, 90], [70, 8, 92], [70, 10, 93], [70, 11, 94],
  // ... (rest unchanged)
  [72, 223, 255]
];
// Dark 'hot' colormap: black → red only
const hot = Array.from({length:256}, (_,i)=>{
  let t = i/255;
  return [
    Math.round(255 * t),
    0,
    0
  ];
});
const cool = Array.from({length:256}, (_,i)=>{
  let t = i/255;
  return [Math.round(255*t), Math.round(255*(1-t)), 255];
});
const rainbow = Array.from({length:256}, (_,i)=>{
  let t = i/255;
  let r = Math.round(255 * Math.max(0, Math.min(1, 1.5 - Math.abs(4*t-3))));
  let g = Math.round(255 * Math.max(0, Math.min(1, 1.5 - Math.abs(4*t-2))));
  let b = Math.round(255 * Math.max(0, Math.min(1, 1.5 - Math.abs(4*t-1))));
  return [r,g,b];
});

self.onmessage = function(event) {
  const { canvas, data, options = {}, gradient = 'viridis' } = event.data;
  const width = canvas.width;
  const height = canvas.height;
  const ctx = canvas.getContext('2d');
  const intensityGrid = new Float32Array(data);




  // Find max intensity for normalization, ignore top 0.1% outliers for better color contrast
  const sorted = Array.from(intensityGrid).sort((a, b) => a - b);
  const max = sorted[Math.floor(sorted.length * 0.999)] || 1;

  function getColor(i) {
    // Log normalization for high contrast
    const t = Math.min(1, Math.log1p(i) / Math.log1p(max));
    let palette = viridis;
    if (gradient === 'hot') palette = hot;
    else if (gradient === 'cool') palette = cool;
    else if (gradient === 'rainbow') palette = rainbow;
    const idx = Math.floor(t * (palette.length - 1));
    const [r, g, b] = palette[idx];
    // Alpha: fade in with intensity, sharper
    const a = Math.round(255 * Math.pow(t, 1.2));
    return [r, g, b, a];
  }

  // Draw pixels
  const imageData = ctx.createImageData(width, height);
  for (let i = 0; i < intensityGrid.length; i++) {
    const [r, g, b, a] = getColor(intensityGrid[i]);
    const p = i * 4;
    imageData.data[p] = r;
    imageData.data[p+1] = g;
    imageData.data[p+2] = b;
    imageData.data[p+3] = a;
  }
  ctx.putImageData(imageData, 0, 0);

  // Transfer rendered bitmap for display
  canvas.convertToBlob().then(blob =>
    createImageBitmap(blob).then(bitmap => {
      self.postMessage({ bitmap });
    })
  );
};