javascript - JS requestAnimationFrame 在给定的赫兹上闪烁

Question

我有下面的代码在给定的时间间隔内闪烁 Canvas ，我怎样才能让它在给定的赫兹(每秒次数)上闪烁

var startTime;
var interval;
var index = 0;
var colors = ['black', 'white'];
var id = null;

function animate(time) {
  id = requestAnimationFrame(animate);

  if (!startTime) { startTime = time; }
  var elapsed = time - startTime;
  if (elapsed > interval) {
    startTime = time;
    canvas.style.backgroundColor = colors[index];
    if (++index > colors.length) { index = 0; }
  }
}

function startBlink() {
  interval = parseFloat(document.getElementById('freqBlink').value);
  requestAnimationFrame(animate);
}

Answer 1

• 频率单位是赫兹(秒^-1)
• 间隔单位为毫秒

然后:

interval = 1000 / frequency