Function sampleTimes

packages/cli/src/commands/motionShotLayout.ts:85–99

(
  dur: number,
  n: number,
  from: number | null,
  to: number | null,
)

/** N equal-time sample points across [from?, to?] within [0, dur]. */
export function sampleTimes(
  dur: number,
  n: number,
  from: number | null,
  to: number | null,
): number[] {
  const t0 = from != null ? Math.max(0, Math.min(from, dur)) : 0;
  const t1 = to != null ? Math.max(0, Math.min(to, dur)) : dur;
  const count = Math.max(1, Math.floor(n));
  if (count === 1) return [t0];
  return Array.from({ length: count }, (_, i) => {
    const t = t0 + (i / (count - 1)) * (t1 - t0);
    return Math.round(t * 1000) / 1000;
  });
}

/** Opacity ramp for the rendered ("ghost") onion-skin: older frames fainter,
 *  the newest frame solid, so the composite of real painted frames reads as a