/* detect.js — tuned ArUco 4x4 detection.
 * Phantom-ID fix: reject any marker decoded with hamming distance > 0 (maxHamming: 0).
 */
export function createDetector() {
  return new AR.Detector({ dictionaryName: 'ARUCO_4X4_1000', maxHammingDistance: 0 });
}

export function detectMarkers(detector, imageData, knownIds) {
  const markers = detector.detect(imageData);
  // keep only markers that exist in the scene, with sane geometry
  return markers.filter(m => knownIds.has(m.id) && quadArea(m.corners) > 100);
}

export function quadArea(c) {
  // shoelace
  let a = 0;
  for (let i = 0; i < 4; i++) {
    const p = c[i], q = c[(i + 1) % 4];
    a += p.x * q.y - q.x * p.y;
  }
  return Math.abs(a) / 2;
}