So you think you know box shadows? • Hacker News Board

Re: So you think you know box shadows?

#41

Post by klysm » Sun, Jul 21, 2024, 6:13 PM UTC

amelius wrote: post #24

sunnyps wrote: post #23

> 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 dr…

Can't you mathematically work out how to change the colors/opacity to rearrange the job?

I think there’s still a dependency graph

Re: So you think you know box shadows?

#42

Post by klysm » Sun, Jul 21, 2024, 6:13 PM UTC

recursive wrote: post #37

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 throws away a lot though, especially w accessibility

Re: So you think you know box shadows?

#43

Post by mavamaarten » Sun, Jul 21, 2024, 6:16 PM UTC

cchance wrote: post #10

He said it might melt your processor... but on a macbook m3 in arc runs great, like every one of those was amazing.

I ran it on my Pixel 7A and even the ray tracing demos ran insanely quickly. I seriously did not expect that.

Re: So you think you know box shadows?

#44

Post by rustystump » Sun, Jul 21, 2024, 6:17 PM UTC

paulirish wrote: post #8

Seriously fun exploration. > Layering. That is an important word. Layering is also the key to the (silly but also sometimes good-looking) effects from my text shadow project from 14yrs ago: https://paulirish.github.io/mothereffingtextshadow/

<3

Re: So you think you know box shadows?

#45

Post by zarathustreal » Sun, Jul 21, 2024, 6:28 PM UTC

ctippett wrote: post #20

I'm embarrassed to admit it took until the final paragraph before realising that 'gypity' is a reference to Chat GPT.

Hmm.. I must be even further out of the loop than you, why would that be embarrassing?

Re: So you think you know box shadows?

#46

Post by rustystump » Sun, Jul 21, 2024, 6:34 PM UTC

leecommamichael wrote: post #35

yesimahuman wrote: post #26

> 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 Any references to learn more about these hacks?

Some historic articles on software rendering (the original Bill Atkinson stuff) https://www.folklore.org/Round_Rects_Are_Everywhere.html http://wg20.criticalcodestudies.com/index.php?p=/discussion/... A modern 3D accelerated article (using SDF as another commenter suspected) https://mortoray.com/quickly-drawing-a-rounded-rectangle-wit...

I was thinking SDFs and the Bill stuff at time of writing. Read my mind.

Have to add work by Evan Wallace here too as he is a legend.

https://madebyevan.com/shaders/fast-rounded-rectangle-shadow... https://madebyevan.com/webgl-path-tracing/

Re: So you think you know box shadows?

#47

Post by Probiotic6081 » Sun, Jul 21, 2024, 6:44 PM UTC

[dead]

Re: So you think you know box shadows?

#48

Post by ulf-77723 » Sun, Jul 21, 2024, 6:49 PM UTC

Really great work, especially the music synced animation - could as well also be projected in an electro club

Re: So you think you know box shadows?

#49

Post by winrid » Sun, Jul 21, 2024, 6:51 PM UTC

This discussion around adding shadows to window boarders in imgui is also interesting: https://github.com/ocornut/imgui/issues/1329

Re: So you think you know box shadows?

#50

Post by amelius » Sun, Jul 21, 2024, 6:53 PM UTC

Rapzid wrote: post #28

amelius wrote: post #24

Earlier quoted context omitted.

Can't you mathematically work out how to change the colors/opacity to rearrange the job?

Having that knowledge sounds just as expensive if the operations aren't commutative.

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.