export const ORBIT_VIEW_DIRECTIONS = Object.freeze([
  "iso",
  "+x",
  "-x",
  "+y",
  "-y",
  "+z",
  "-z",
]);

const ORBITS = Object.freeze({
  iso: Object.freeze({
    yaw: -Math.PI / 4,
    pitch: Math.asin(1 / Math.sqrt(3)),
  }),
  "+x": Object.freeze({ yaw: -Math.PI / 2, pitch: 0 }),
  "-x": Object.freeze({ yaw: Math.PI / 2, pitch: 0 }),
  "+y": Object.freeze({ yaw: Math.PI, pitch: 0 }),
  "-y": Object.freeze({ yaw: 0, pitch: 0 }),
  "+z": Object.freeze({ yaw: 0, pitch: Math.PI / 2 }),
  "-z": Object.freeze({ yaw: Math.PI, pitch: -Math.PI / 2 }),
});

/**
 * Return the orthographic camera orbit for a view from the named axis toward
 * the array origin. A fresh object prevents one view from mutating another.
 */
export function orbitForViewDirection(direction = "iso") {
  const orbit = ORBITS[direction];
  if (!orbit) {
    throw new RangeError(
      "view direction must be one of: " + ORBIT_VIEW_DIRECTIONS.join(", "),
    );
  }
  return { ...orbit };
}