Function decodeExtSplat

src/utils.ts:430–456

(
  extArrays: [Uint32Array, Uint32Array],
  index: number,
)

}

export function decodeExtSplat(
  extArrays: [Uint32Array, Uint32Array],
  index: number,
): {
  center: THREE.Vector3;
  scales: THREE.Vector3;
  quaternion: THREE.Quaternion;
  color: THREE.Color;
  opacity: number;
} {
  // Returns a static object which is reused each time
  const result = packedFields;
  const i4 = index * 4;
  const [extA, extB] = extArrays;
  result.center.x = uintBitsToFloat(extA[i4]);
  result.center.y = uintBitsToFloat(extA[i4 + 1]);
  result.center.z = uintBitsToFloat(extA[i4 + 2]);
  result.opacity = fromHalf(extA[i4 + 3] & 0xffff);
  result.color.r = fromHalf(extB[i4] & 0xffff);
  result.color.g = fromHalf(extB[i4] >>> 16);
  result.color.b = fromHalf(extB[i4 + 1] & 0xffff);
  result.scales.x = Math.exp(fromHalf(extB[i4 + 1] >>> 16));
  result.scales.y = Math.exp(fromHalf(extB[i4 + 2] & 0xffff));
  result.scales.z = Math.exp(fromHalf(extB[i4 + 2] >>> 16));
  decodeQuatOctXy1010R12(extB[i4 + 3], result.quaternion);
  return result;
}

// Encode a PackedSplat as 4 consecutive Uint32 elements in the packedSplats array.
// The center coordinates x,y,z are encoded as float16, the scales x,y,z as a