units.ts

/** Display unit systems for the UI (independent of the scene's stored units). */
export type UnitSystem = 'imperial' | 'inches';

export function formatImperial(inches: number, opts: { precision?: 'inch' | 'eighth' } = {}): string {
  const sign = inches < 0 ? '-' : '';
  const abs = Math.abs(inches);
  const feet = Math.floor(abs / 12);
  const remIn = abs - feet * 12;

  if (opts.precision === 'eighth') {
    const eighths = Math.round(remIn * 8);
    const whole = Math.floor(eighths / 8);
    const frac = eighths % 8;
    const fracStr =
      frac === 0
        ? ''
        : frac === 4
          ? ' 1/2'
          : frac === 2
            ? ' 1/4'