RequestHertzFrame.js

RequestHertzFrame.js

class RequestHertzFrame
{
  static get DEFAULT_UNKNOWN_HZ ()
  {
    return {
      hz: NaN,
      request: requestAnimationFrame,
      cancel: cancelAnimationFrame,
    };
  }
  
  static get KNOWN_50_HZ ()
  {
    return {
      hz: 50,
      request: cb => setTimeout(cb, 1000 / 50),
      cancel: id => clearTimeout(id),
    };
  }
  
  static get KNOWN_60_HZ ()
  {
    return {
      hz: 60,
      request: cb => requestAnimationFrame,
      cancel: id => clearAnimationFrame,
    };
  }
  
  static InRange(min = 60, max = 60)
  {
    return new Promise((yup, nope) => {
      if (isNaN(min) || isNaN(max)) {
        nope('min & max requested rate must be Numbers');
      } else if(min === min && 60 === max) {
        yup(RequestHertzFrame.DEFAULT_UNKNOWN_HZ);
      } else if (-Infinity === min) {
        // do some race between rAF & rIC ?
      } else if (false) { // replace with hardware detection
      } else {
        nope('Unsupported');
      }
    });
  }
  
  static MultipleOf(mode=0, ...hz=60)
  {
    // do magic gubbins to figure out closest appropriate hz
    
    // i.e. RequestHertzFrame.MultipleOf(12,15,50,60),
    // where mode determines whether a 120hz monitor gives a 60fps requester or a 120fps requester
    
    // where a tab has fullscreen content AND a monitor supports variable refresh rates,
    // some value of mode should allow the previous example to drive a 48/96/144fps requester over a 50/100/60/120fps requester
  }
}