It's not crazy. That is literally what 99.99% of video games do. They repaint everything constantly, only limited by either your vsync rate or hardware.
That's exactly what I was saying. Rendering a few widgets shouldn't pin your CPU or GPU because it's so little work.
This page, however, has an animated SVG and moving DOM elements in the header which consume far more resources than the widgets it is trying to showcase. Compare usage before and after deleting the header element (`section.hero`) in the inspector to see for yourself.
> That's exactly what I was saying. Rendering a few widgets shouldn't pin your CPU or GPU because it's so little work.
Your comment doesn't say this at all:
> > This is the kind of thing usually a human notices and says 'dont do that, that is kind of crazy'.
> It's not crazy. That is literally what 99.99% of video games do. They repaint everything constantly, only limited by either your vsync rate or hardware.
Am I missing something? Are you referring to some other part of the thread?
He's right - the DOM also has observers.
The difference is what is rendered, not that observers are involved and the concept of looping.
Millions use React - you want to talk about performance?
Anyway, something like this only needs to paint when states change or animations are running. That's an easy optimization to make here if it doesn't do it already. And games don't even bother with it, they repaint all UI even if it doesn't change.
All this work to replicate the animated blobbiness of Liquid Glass. I thought everyone hated it! So, then, why is this a thing?
It does in my mind. I fully expect visiting any of reddit.com, github.com, notion.so, or meet.google.com to have the chance to pin a cpu core at 100% for as long as the site is open.
At this point, I expect the average webpage to use more CPU than any of the video games I play. The only reason I had to upgrade to my current machine is because a 2021 CPU (intel gen 11) wasn't capable of running notion.so or google meet anymore, it still ran all the video games I care about just fine.
CPU bound games examples: Chess, Go, Final Fantasy XIV, Elite Dangerous, and any competent Civilization / 4X or turn-based strategy game. Yes, you can dial up the graphics on these to force them to be GPU bound, but they’re each CPU bound in their own unique ways. Perhaps none such games appeal to you, but as with above, extrapolating from personal preferences is a non-starter.
Non-tech people teach each other to force-quit apps to stop their battery drain. Websites aren’t apps, so their phone ‘randomly’ gets hot sometimes and they either have no idea why or just try closing all tabs in a vague hope that it works. Sometimes a webpage uses up all their data for the month downloading ads and so they stop using the web over cellular at all.
This is the baseline level of competence that improving the web must be aiming for — not ‘web developers will understand that the tab is using lots of battery and must be closed’. Making the web better is not about making the web significantly more battery-hungry, no matter how pretty it might seem. No visual advancement in radio button UX is worth a continuous repaint in JavaScript.
The websites I mentioned use more cpu and memory than most games in Civilization the series, which are largely competently developed. My previous laptop could play civ 5 at a higher framerate than it could scroll github diffs or notion pages. Civ 5 handled full-speed keyboard input, while notion doesn't let me input text at my roughly 100 wpm typing speed.
I agree that we shouldn't be expecting users to figure out how to close the right tab, however I'm reporting the way things currently are, which is that webpages are poorly optimized messes.
Point being: your comment made me sad and I needed to lighten myself up a bit.
To be clear, I'm not saying it's fine to constantly render when you know nothing changed. I'm saying the load from this should be very small. Most of the performance issues from this page are actually from the header animation, which you can delete in the inspector to see a significant drop in usage (mine went from ~35 to ~6.6 CPU).
Do you know that regular HTML and CSS use GPU all the time?
That's what this thread is about, I thought.
A videogame is expensive to render because of several MB models, constantly moving camera, and other things.
The concept of observing elements is not even new.
These downvoters act like native JS doesn't do the exact same thing with event listening and observing the DOM. So does React and other FE frameworks.
Philip J Fry is either being disingenuous or genuinely doesn't know that game rendering has often several MB models, is often raycasting, maintaining camera calculus, and a lot more.
But many smaht people out there don't know that.
For instance, the mouse cursor is composited on the GPU during scanout. That means simply moving your cursor requires zero rendering.
Another example: When typing only the newly typed character and caret are rendered. The rest of your entire screen is reused.
You're right that they avoid unnecessary painting but it is not this granular anymore. It used to be but rendering is so much faster these days where it is cheaper to just render a bit more than tracking dirty regions. It's easily visible on Android where you can enable "Show view updates" and see the entire textbox view updates when the cursor flashes. The docs say the same thing.
https://developer.android.com/reference/android/view/View#in...
Chrome on desktop has an option for flashing whenever it paints and it only highlights the line of text you're typing on. So clearly chrome still tracks dirty rects properly.
It's likely the same on iOS. You'd have to try implementing it to really see why it isn't practical.
Consider you were implementing drawing a button. Your UI framework calls your draw method with some interface to draw with and gives you a rectangle specifying the region to draw. Your button is probably some form of rounded rectangle which will be complicated to draw a subsection of if the rectangle intersects a corner. If it intersects the button's text then you probably need to figure out which characters intersect the text and only render those. It's a non-trivial amount of work to cull the draw commands to an arbitrary region. Also, if you stop passing dirty regions around then the widget drawing method is closer to being a pure function meaning the UI framework can cache the draw instructions instead of calling it over and over for different regions.
> Chrome on desktop has an option for flashing whenever it paints and it only highlights the line of text you're typing on. So clearly chrome still tracks dirty rects properly.
Looks like it but it doesn't show any renders for the cursor flashing so I don't fully trust it.
The way this is done everywhere is to invalidate the entire area of the button. Buttons usually change background on hover/click anyway, so it just doesn't make sense to do more. Text input is special because these widgets can be very large, sometimes spanning the whole screen, so you want fine-grained dirty regions.
> Also, if you stop passing dirty regions around then the widget drawing method is closer to being a pure function meaning the UI framework can cache the draw instructions instead of calling it over and over for different regions.
I've never heard of anyone adding a general Widget-Level cache, considering that most UI elements don't change position that would be quite expensive. In any case the rendering is still a "pure" function regardless of whether you're using dirty regions or not, so not sure what you're trying to say here.
> Looks like it but it doesn't show any renders for the cursor flashing so I don't fully trust it.
That is definitely weird, but it still clearly shows that the regions are being tracked.
The DOM does this. React does this.
Did you know CSS even invokes the GPU for certain tasks?
You guys really need more experience. I can't believe how many people apparently know nothing at all about web dev and computers.
The processes don't stop, no, but they do pause and go idle, waiting for the next event to come in. Not sure what that has to do with this.
> The DOM does this. React does this.
What does react have to do with any of this discussion, and what do you mean by "this"?
> Did you know CSS even invokes the GPU for certain tasks?
Whether the GPU or CPU does work is unrelated to how frequently and how much of the screen is rendered. Damage regions work just fine for GPU-based rendering.
> You guys really need more experience. I can't believe how many people apparently know nothing at all about web dev and computers.
Part of my job is maintaining a retained mode UI library. I've literally written some of the parts that handle damage regions, as well as the GPU-based rendering. But do go on about how I don't know how any of this works.