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In the past two months or so, I spent some time making tiny GLSL demos. I wrote an article about the first one, Red Alp . There, I went into details about the whole process, so I recommend to check it out first if you're not familiar with the field. We will look at 4 demos: Moonlight , Entrance 3 , Archipelago , and Cutie . But this time, for each demo, we're going to cover one or two…
Text rendering is cursed . Anyone who has worked on text will tell you the same; whether it's about layout, bi-directional, shaping, Unicode, or the rendering itself, it's never a completely solved problem. In my personal case, I've been working on trying to render text in the context of a compositing engine for creative content. I needed crazy text effects, and I needed them to be…
Bézier curves are a core building block of text and 2D shapes rendering. There are several approaches to rendering them, but one especially challenging problem, both mathematically and technically, is computing the distance to a Bézier curve. For quadratic curves (one control point), this is fairly accessible, but for cubic (two control points) we're going to see why it is so hard. A glyph…
A few weeks ago, I made a tiny demo that fits into 448 characters: Red Alp GLSL demo in 448 characters void main(){vec3 c,p,K=vec3(3,1,0);for(float z,i,a,g=1.,t,h,d,w,k=.15;i++<1e2;d=max(max(d-3. ,-d),a=z)*k,w=g-g/exp(h>.001?a++,d/.4:h*3e2),g-=a*=w,c+=a*d*4.5+(d>z?z:h/2e2)*K,a=min(p.y+2. ,1.),c.r+=w*a*a*.1,t+=min(h*.2,k/=.985))for(p=normalize(vec3(P+P-R,R.y))*t,p.xz*=mat2(cos(…
Doing anti-aliasing on SDF is not as straightforward as it seems. Most of the time, we see people use a smoothstep with hardcoded constants, sometimes with screen space information, sometimes cryptic or convoluted formulas. Even if SDFs have the perfect mathematical properties needed for a clean anti-aliasing, the whole issue has a scope larger than it appears at first glance. And even when…
The idea that we must always linearize sRGB gradients or work in a perceptually uniform colorspace is starting to be accepted universally. But is it that simple? When I learned about the subject, it felt like being handed a hammer and using it everywhere. The reality is a bit more nuanced. In this article we will see when to use which, how to use them, and we will then see why the situation is…
You've most likely heard about gradient noise through the name Perlin noise , which refers to one particular implementation with various CPU optimizations. Because it's an incredible tool for creative work, it's used virtually everywhere: visual effects, video games, procedural mathematical art, etc. While getting it right can sometimes be subtle, a "broken" implementation can still…
As I'm exploring the fantastic world of indie game development lately, I end up watching a large number of video tutorials on the subject. Even though the quality of the content is pretty variable, I'm very grateful to the creators for it. That being said, I couldn't help noticing this particular bit times and times again: a = lerp(a, B, delta * RATE) Behind this apparent banal call…
This write-up is meant to present the rationale and technical details behind a tiny project I wrote the other day, WTH, or WindowTitleHack , which is meant to force a constant window name for apps that keep changing it (I'm looking specifically at Firefox and Krita, but there are probably many others). Why tho? I've been streaming on Twitch from Linux (X11) with a barebone OBS Studio…
In 2015, I wrote an article about how the palette color quantization was improved in FFmpeg in order to make nice animated GIF files. For some reason, to this day this is one of my most popular article. As time passed, my experience with colors grew and I ended up being quite ashamed and frustrated with the state of these filters. A lot of the code was naive (when not terribly wrong), despite the…