Code golfing a tiny demo using maths and a pinch of insanity
blog.pkh.me101 points by ux 3 days ago
101 points by ux 3 days ago
I don't know much about 3d stuff or shaders or this language, but I know golf, and I think I found a byte to save.
w = g-g*exp(-mix(h*3e2,d*2.5,a=h<.001?0.:1.))
w = g-g/exp(mix(h*3e2,d*2.5,a=h<.001?0.:1.))You can also premultiply w with a, as every occurrence of `w` looks like `w*a`. This should shave three more bytes:
w=g-g*exp(...),g-=w*a,c+=w*a*d*9.+...,c.r+=w*a*a*2,...
w=g-g*exp(...),g-=w*=a,c+=w*d*9.+...,c.r+=w*a*2,...
This is not equivalent; the `a` in `c.r+=w*a` is different, you need the original untouched w. The mountain looses its crack with your version.
But! You can save 1 char by replacing w with a:
g -= a*=w,
c += a*d*9.+...
a = min(...),
c.r += w*a*a*.2,
Hey, thank you, that's a nice one. I added the change to the Shadertoy version with your credit. I will add a note/update on the blog and demo page later. Thanks again :)
Is it actually necessary to specify `a` as a floating-point literal? Will it not be implicitly converted?
Yeah. If you want implicit conversion, you need to specify a constructor like float(cond), but that would be longer than the ternary form. I thought about using a vec3() but vec3(...).x is still too long and using the vec3 directly doesn't look viable. Declaring a bool adds more characters as well. There is also step() giving the same number of chars: a=step(.001,h), but it's not more optimal: https://iquilezles.org/articles/gpuconditionals/
If you see a way to make it shorter, feel free to share :)
Using maths, insanity, and a ton of calculation horsepower... That made my graphic card fan turn on instantly!
The top demo doesn't function on Edge or Chrome on Windows due to too many webgl contexts.
> WARNING: Too many active WebGL contexts. Oldest context will be lost.
Ah, someone reported this to me today, but I must admit I have no idea how to address the issue. Currently the canvas animations are stopped when out of context, but yeah they have to be loaded.
The code on the blog is pretty simple and naive (I'm not a webdev): https://github.com/ubitux/scripts/blob/main/share/blog/shade...
Any suggestion on how to address the issue is welcome.
Note: I don't have any Windows machine to test with
If you just want it to work, stick this script on your page
https://github.com/greggman/virtual-webgl
If you want to make your own solution there's one listed here about 1/2 way down the page
https://webglfundamentals.org/webgl/lessons/webgl-multiple-v...
As an aside, WebGPU doesn't have this issue or at least has it less. For one, WebGPU can use a single device to render to multiple canvases, something WebGL can't. Another is that WebGPU is mostly stateless making it easier for both the user and the browser.
Incredible, thank you very much. I've included the script for a quick fix, I'll see how to make to cook something myself at some point!
Similar issue on iOS Safari: all examples work except for the very first one.
Works fine with Firefox on Windows.
What am I saying? Fine? It's freaking awesome.
Unbelievably cool, well done!
Needs dragons flying sunwards
If anyone is interested in learning more about this kind of coding https://thebookofshaders.com/ is a fantastic intro.
Is this tutorial kind of abandoned? There are many teased chapters that never seem to have materialized somehow.
This is utterly bonkers to me, well done.