package main

import "time"

const guiFrameInterval = time.Second / 60

// videoPollInterval bounds GUI latency when no video producer is waiting.
// It is not a video-rate cap: Next returns immediately whenever a frame
// arrives, including for sources faster than this interval.
const videoPollInterval = 8 * time.Millisecond

func remainingFrameTime(start, now time.Time, interval time.Duration) time.Duration {
	remaining := interval - now.Sub(start)
	if remaining < 0 {
		return 0
	}
	return remaining
}

func paceFrame(start time.Time) {
	if remaining := remainingFrameTime(start, time.Now(), guiFrameInterval); remaining > 0 {
		time.Sleep(remaining)
	}
}