About

The white bars should move perfectly smoothly. Follow them with your eye. Any jank/jitter = FAIL The top bars are timer based, the bottom ones advance a fixed number of pixels per frame. If the bottom bars are jittery, frames are skipped or displayed for uneven periods. If the bottom bars slowly fall behind the top ones, the interval timer is inaccurate. If the top bars are jittery, the "new Date()" timer is unsmooth or frames are skipped.