> However, using a transparent color significantly slowed down the number that can be drawn too which doesn't make as much sense to me. I'd imagine that with hardware today transparency should be somewhat free.
That's because transparency limits how you can batch draws on the GPU. With opaque draws, you can use the depth buffer and draw in any order you like e.g. maximizing batching. With transparency, you need to draw things in the right order for blending to work (painters order).
I think it's more complex than that. While web browsers do use GPU rendering, they're not game engines. They don't draw every single object on the screen every frame, that could easily cause lag on a large complex page.
Chromium in particular tries to minimize the total number of layers. It renders each layer into a pixel map, then for each frame it composites all of the visible layers into the final image.
That works really well in practice because you often have lots of layers that move around but don't actually change their pixels. So those don't need to be rendered (rasterized) every frame, just composited.
If you have a bunch of box shadows without transparency, Chromium will rasterize the whole thing once as a single layer.
If you have a bunch of box shadows with transparency, Chromium might create a separate layer for each one. That's probably suboptimal in this particular case, but imagine if your partially transparent box shadows had to also slide around the page independently.
I think the above was a simplification. GUI rendering is a good example of jack of all trades, master of none. It doesn't use tight render loops like game engines but it much more flexible in terms of UI possibilities.
There is also the issue that GPU's are oddly terrible at generating 2D elements of which a desktop has thousands of them. There are things like Glyph caching but they can only go so far.
Having the CPU doing the majority of the work with a few rasterization tasks to the GPU makes sense.
> There is also the issue that GPU's are oddly terrible at generating 2D elements
I never knew this and honestly I’m a bit baffled - 2D seems simpler on its face, is it just that GPUs have been made with gaming in mind (typically) and most “hardcore gamers” are playing 3D games?
I can't find it right now, but I recall reading an article years ago where a newer, more powerful generation of GPUs turned out to have much less hardware for 2D operations/calls, and a fraction of the 2D performance, but the performance in 3D games went up so nobody really noticed.
Games are expected to have sole access to your machine, so if they use all the CPU/GPU resources, nobody cares. If my web browser was burning up my battery re-rendering the page 90 times a second, I'd be livid.
I think “consumes too much resources” is a valid concern. But I think “could cause lag because too many objects” is totally bogus. Rendering a web page isn’t that complicated.
I wouldn’t have thought so either, and then I learned the order in which CSS rules are applied and I’m convinced browsers have some of the most complex rendering engines out there.
> Games are expected to have sole access to your machine, so if they use all the CPU/GPU resources, nobody cares. If my web browser was burning up my battery re-rendering the page 90 times a second, I'd be livid.
Games 20 years ago had sole access to machines that were much less powerful than even partial access to today's machines.
And eg Nintendo Switch games (or games on the Steam deck, or just mobile phone games) still deal with power limitations; people are very aware when their games burn through their batteries.
Reverse-painter's-order beats painter's-order since it lets you skip fully-occluded objects:
Start with a buffer that's fully transparent (α=0.0)
for each face from front to back:
for each pixel of the face:
draw the pixel, blending 1.0-buffer.α of the new pixel into whatever's already in the buffer
(if buffer.α == 1.0 you can just skip it entirely, just like for depth buffering)
go back and double check your math relating to transparent objects behind other transparent objects
The tricky part is if you have faces that overlap in a cycle (can happen legitimately), or that penetrate each other (often avoidable if you think about it).
The game engines I've dealt with separate opaque and transparent geometry.
It is generally good to render opaque geometry back to front to reduce overdraw, but not going so far as sorting the objects. We would do stuff like render the hands first in an FPS or render the skybox last in most games.
Now for the transparent layer: First occlusion is handled by the z-buffer as usual. If you render from front to back I assume you render to another buffer first and then composite to the framebuffer? If you render from back to front you don't need alpha in your framebuffer and can assume each rendered pixel is opaque, not needing that composite.
There's also order independent transparency stuff though which IIRC does need another buffer, which requires a composite but then saves you having to sort the objects.
I could be wrong, but I remember folks that worked on Dreamcast games that loved how you could just throw the geometry at it in any old fashion you liked and the GPU would just sort it all out as needed. Transparencies and all.
GPUs also do not like overdraw, so it's generally good idea to avoid having many transparent elements on top of each other, its also the reason why drawing more triangles vs. transparent texture is generally better.
My big take away with the whole City Skylines 2 performance issue and the lack of LOD was that geometry processing is so cheap nowadays. So long as you aren't too reckless with geometry in terms of sub-pixel rendering, you don't really have to worry about it too much any more.
It isn't like the Ps2 era when geometry time was a real concern on render times. Even a modern low end GPU could process a few hundred million polygons a second without sweating it, now getting the result son screen is a very different issue.
Yeah, PS2's Graphics Synthesizer had a fill rate of 1.2 GB/s. For comparison, the OG Xbox had 0.932 GB/s, and the GameCube had 0.648GB/s. Assuming only 1 texture here.
The Xbox was released 1 year later, for context.
Sony also demo'd the GSCube once, it had 16 Graphics Synthesizers, achieving a fill rate of 37.7 GB/s (no textures, half that with 1... I think). Eventually they ditched the idea in favour of Nvidia's solution.
The "Ordering" step doesn't really matter that much. You're usually doing a sort anyway prior to submitting the drawcall. What hurts is the overdraw. If you're doing opaque rendering, you get to render front to back, rendering only what actually appears on the final framebuffer. The number of pixels (after the depth pass) is proportional to the framebuffer. When you're doing transparent rendering you render back to front, and you have to render a tonne of the scene that will eventually be (partially) obscured by other random polys. We call that overdraw. The amount of pixels through the shader pipeline balloons to be proportional to the size of your mesh.
If you're doing non-overlapping stuff, you'd actually expect (almost) no slowdown from transparency, since you'd have to touch every pixel once anyway, and the only thing that changed is the shader formula.
One more thing to consider is memory bandwidth, which can be limiting factor especially on mobile devices.
A non-transparent draw over another draw allows in best case to cull all overlapping drawing operations, in worst case means you only have to use as much bandwidth as the individual draws.
With transparency, especially if you can't somehow combine the operations together (from my understanding, very hard problem), it means you also need to read back the entire region you're overlapping with transparency - so every transparent draw involves at least twice the final framebuffer size bitmap going-over memory bus.
Now consider that many mobile devices had not enough memory bandwidth to do a full redraw (i.e. blit the full framebuffer image twice) of the screen in time to maintain 60fps and it becomes a considerable problem.
Yeah, somehow between comments I forgot this was about shadows and I was thinking more about drawing polygons. In that case, you can break up the polygons and work out the colors for each of the (theoretically 2^N) regions of overlap.
I'm totally down for some good old fashioned impractical hacking. But just remember, we already have canvas, which can do all this easier, faster, and better.
Canvas would still be faster even if you used a full-screen box. Just the string concatenation overhead of doing this with box-shadows is insanely wasteful.
Which isn't to demerit the hackish creativity of taking one thing and running with it! But if you wanted to do a ball painting effect like that outside this "what if" context, it would be technically irresponsible to do it with box-shadows.
Looking at the music visualizations was definitely cool. Really miss the old winamp days when you could play music and just run the visualizer full screen. I wish that streaming audio players did this today.
Still use Winamp (actually WACUP) with Milkdrop visualizations almost every day. But true that streaming audio players are so basic featureless pieces of software.
AVS and Milkdrop could probably run on a toaster today, I'd guess even WebGL would be enough on a smartphone, laptop or similar device with some kind of GPU.
Meanwhile, YTM costs 13€ a month, doesn't have an equalizer, no cross-device sync despite cloud everything... no nothing. Not even gapless album playback.
Once upon a time, I signed up to Spotify in order to have a good conscience, because I grew old and didn't want to keep collecting audio files...
Then Spotify became worse and worse.
For now YTM seems like a better deal, but I still can't even find a free solution to migrate my playlists.
Basically, everything went to shit. The only advantage is not having to illegaly download new music after browsing Discogs.
The disadvantage is, apart from the odd good recommendation, my interest in discovering new music has vanished.
Even new music found on Discogs.
But why bother saving songs to playlists when it's all transient anyway?
That was my main last straw with Spotify — too many good music disappearing from playlists, and steadily worsening recommendations. With rabbit-holes of totally trash AI-generated "music" in between, that didn't stop unless actively skipping.
And YTMs not gonna end any better, I feel.
Just a reminder that all music is transient. And maybe to seek regaining enthusiasm by playing music myself, or going out.
Streaming really has killed "listening to music" and being excited about it for me, and I don't feel it's purely because of old age.
Going to revive my Mp3 collection soon from a backup and download my ~25 records worth listening since 2012 then from Bandcamp instead.
I feel very similarly... I have YTM mostly because I don't like ads on Youtube and found out creators get more from YT subscribers than from the ads.
I have the UX of the player though... the android TV experience is even worse, it's nearly impossible to use effectively now.
I miss DJs, at least I miss good DJs... there are a few stations locally that I like what the DJs will mix and play, but there's sooo many commercials now. I'd happily pay $10/month for an ad-free DJ run experience. I mean, why the likes of XM, etc don't just have 50-100 DJs actually curate the music for the live experience.
Thinking about that, I was happy about Rinse.fm still existing and a couple of other stations still playing live sets – not that I like everything, but when a DJ hits the spot, it's really satisfying.
Live sets generally are an antidote to this kind of music fatigue for me.
Of course there are other remedies, e.g. timeless albums and live music, I also a deep love for Bach's keyboard music, and some of that proved to me how much context matters for enjoyment.
And ditto about Youtube, it's not a bad offer in itself but the music app really sucks, many parts of Google TV are mediocre, too. In the latter case, I appreciate their effort in that case though (gtv in general), and the p/v I get from that 40€ hdmi+usb stick is not too bad either since i use a cheap chromecast.
That's a thing I still like Google for, at least in my case Chromecast makes it possible to reuse a cheap ~10y old LED tv for purely internet tv, with a functional remote, etc.
It's not new, but Google's TV sticks are pretty decent imo
> It also turns out that some smart people figured out maths hacks to draw rounded boxes for super cheap which UI peeps love because with this hack boxes can be so round as to appear as circles
A great, possibly the greatest article I read this year ended with "your welcome" instead of "you're". Fix asap! Or maybe I didn't get the joke, that's a possibility
For the past 30 years I got good at programming but never really did graphics because I didn't like games. I now view it as a massive oversight and have been trying to catch up for over a year.
Well, games are seen as fun, so they can attract programmers even with low salaries.
Basically the same reason pet veterinaries and teachers and nurses and musicians and artists still attract plenty of candidates despite a comparatively low pay.
(Playing games is more fun than working with CRUD apps. But writing games and writing CRUD apps seem about equal in their probability distributions of fun.)
Most of this is about the not-so-much-anymore-exotic art of GPU programming. It's becoming important in so many fields. The last thing I want to be is some foot-dragging old windbag who forgot to stay up to date.
As long as you get the job done within the estimates and make the client happy you're meeting your employment or job obligations. There is a lot of high paying salaries where people still parse csv jobs, and perform manual reporting with excel files.
This may sound laughable but I'm only in technology to build the future, I don't actually care about the money. Despite the current trend of tech pessimism, I still believe in tomorrow.
Gramsci's pessimism of the intellect, optimism of the will can be a tough motivator but I'm trying.
Are you building your future? I'm 41, and there are probably other users here who're older than me how-ever I was told when I was 16 that ftp/smtp/csv/https/oracle/database are legacy technologies but every day its my bread a butter. Technologies will come and go but your time is more important than trying to build for the future.
Just recently one of our security experts dropped dead over the weekend. When everyone heard about it they were sad for about 5 minutes, then 5 minutes later everyone was talking about their kids, parents, family, vacations or what they're going to have for lunch.
I don't mean that to be condescending, your life is important to you. Build your future, technology will take care of itself.
Come on. It's thanks to articles like these I can finally have LLM write all those bullshit CSS hacks for me, and I even get to keep rejecting its commits until it gets it right!
(Though honestly, right now, getting GPT-4o to do responsive layout is an exercise in frustration equivalent to doing it myself.)
That's because transparency limits how you can batch draws on the GPU. With opaque draws, you can use the depth buffer and draw in any order you like e.g. maximizing batching. With transparency, you need to draw things in the right order for blending to work (painters order).