About the Snow Script

programming
1

The snow script works nice on my page but when I go to another tab in chrome and later come back to the tab of my page the script acts strange, lesser en slower flakes

2

Do the snowflakes come back after a bit, or are they always permanently less in quantity?

3

Oh, I see what @Izawebmaster is saying about revisiting a tab. I think requestAnimationFrame or some similar API is throttled for background tabs. And yeah they do come back.

Presumably there’s a JavaScript / DOM API these days to detect that sort of throttling, as you could do in ActionScript back in the day.

1 Like
4

(Or if there’s no API, checking the time between rAF calls would be functionally equivalent for the most part for big delays.)

5

After a while there is no snowflake left

6

A modification to the first few lines of moveSnowflakes would probably fix it:

    let tbtU = 17 // milliseconds
    function moveSnowflakes(currentTime) {
      tbtU = (tbtU + (currentTime - previousTime)) / 2
      delta = (currentTime - previousTime) / frame_interval
      previousTime = currentTime
      console.log(tbtU)
      if (performance.now() > 10000 && tbtU > 70) {
        console.log("pause")
        requestAnimationFrame(moveSnowflakes)
        return
      }

It’s basically just a check to say… hey if we’re not hitting our frame budget at all (probably due to unfocused tab throttling), stop updating the snowflake positions.

2 Likes
7

Yes! That worked.
Thank you so much for your help.

The MoveSnowflakes section I now use:
let tbtU = 17 // milliseconds
function moveSnowflakes(currentTime) {
tbtU = (tbtU + (currentTime - previousTime)) / 2
delta = (currentTime - previousTime) / frame_interval
previousTime = currentTime
console.log(tbtU)
if (performance.now() > 10000 && tbtU > 70) {
console.log(“pause”)
requestAnimationFrame(moveSnowflakes)
return
}

1 Like