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by sagebird 2400 days ago
There is nothing preventing setting a debounce function to update frequently. For example, why would you want to calculate updates more than 30 times a second, or why would you want multiple updates during a single animation frame ( ie update faster than the browser repaints)? Debouncing is an insurance policy against insane things that you don’t want to happen. A smart debounce function can even modify itself in response to how long an expensive function is taking on average for a particular device— to increase the debounce time if there is not sufficient time to complete one calculation before another begins. I’ll go as far to say that a properly tuned debounce function that is triggered on leading edge will, if anything, decrease perceptible lag, not add to it. It will also minimize (though not guarantee w/o additional mechanisms) out-of-sequence updates. Out of sequence updates can lead to janky/confusing behavior.

— edit: I see that I went off the deep-end, assuming that you were against using debounce functions in general. I now see that grandparent was conflating debouncing and not updating until slider comes to a stop. These are of course not the same thing. Apologies. I hope my comments on debouncing are useful to someone though.

1 comments

Presumably just listening to the slider state and updating some global variables is fast enough to not need throttling, but I would definitely update the SVG DOM inside a draw loop running in requestAnimationFrame since there's no point in doing it any faster than that anyway.

I'm not an expert on high-frame-rate web drawing, but I've played with it a fair amount, and AFAIK there's no need to do any fancy debouncing logic beyond requestAnimationFrame.

A need may arise if a calculation took longer than a frame. (I’ve encountered this making a little programming language that generates graphics that updates in real time as you type. I’d imagine similar issues with web based latex-> pdf generators that update the pdf as you type )
If a calculation takes longer than a frame, then you’re going to stutter no matter what you do, right? I feel like the browser will do its best to let you interact with the slider between frames, but really I can’t think of a good way to have a smooth interactive UI with calculations that take more than a frame.