Here's a pretty efficient quicksort implementation in macro form for C. It being a macro means the compare function can be inlined instead of being through a function pointer. Code is a horrible macro mess, but it works gist.github.com/mattiasgusta...

Is there a good online community (discord or whatever) for disussing specifically C programming (and only C programming), without being centered around a specific codebase? And to be precise, hand coded C, not AI generated or vibe coded. Got any tips for such spaces?

I wrote a bit about my plans for Audio capabilities, for my fantasy console "Pixie Game System". Would love to hear your thoughts on it: github.com/mattiasgusta...

For the fantasy console I'm making, "Pixie Game System", I have a first complete spec for the CPU opset. You can read more about it here: github.com/mattiasgusta...

I wrote a bit about my plans for Audio capabilities, for my fantasy console "Pixie Game System". Would love to hear your thoughts on it: github.com/mattiasgusta...

we’ve got somewhere to stay after the fucking place flooded again, just a room tho, I’ve just managed to pack the bare minimum and I’m skint beyond words. I am so sorry, this has all gone to shit. Can anyone help with emergency survival funds? www.paypal.com/paypalme/ret... ko-fi.com/robfearon

For the fantasy console I'm making, "Pixie Game System", I have a first complete spec for the CPU opset. You can read more about it here: github.com/mattiasgusta...

I've created a repo for it on github, and I will use the "discussions" feature to talk about it: github.com/mattiasgusta... If you are interested in the project, or want to contribute ideas or even code, feel free to join the discussions :)

Last year, I started prototyping a fantasy console, but didn't really get it off the ground the way I'd hoped. This year, I want to really make some headway, and move from prototyping to start working on it properly. I've named it "Pixie Game System"

Last year, I started prototyping a fantasy console, but didn't really get it off the ground the way I'd hoped. This year, I want to really make some headway, and move from prototyping to start working on it properly. I've named it "Pixie Game System"

This past year has, without a doubt, been the toughest year ever for both my wife and me. I do feel hopeful about the year to come, and we do believe the worst is behind us. I hope all of you will get a great 2026.

implementing a custom codegen backend for TCC is tricky...

I am excited to share this new single-header C library I have been working on for a while now: vecmath.h, a comprehensive vector/matrix math library for graphics/games/3d. It allows you to write vector math code in C that looks like this:

I tried my hand at making a video codec. I didn't know the first thing about video codecs when I started, so was quite fun to learn about the concepts and how to implement them. I packaged the result in a stb-style, single-file header-only lib, < 2500 loc with no dependencies.

what are the worst things about the modern day internet?

Got back into using the video editing features of Blender to make a trailer for some of my open source shenanigans - Announcing: DOSBox Pure Unleashed 🥳 www.youtube.com/watch?v=t4q8...

The single header lib also includes source code for an encoder utility and a playback app (both which makes use of other single header libs), behind conditional compile switches (ifdefs). Instructions for how to build them can be found at the top of the file.

The code is public domain, and available here github.com/mattiasgusta... For most uses, you are probably better off using a real codec. But for something small, simple, self-contained with no dependencies, this might fit the bill.

The videos in the examples are compressed with my "default" setting, which makes them quite small, with ok-ish quality. On "max" they are more like dvd in size/quality. I focused on avoiding temporal aliasing, and I think i pulled that off quite well.

All in all, it seems like my quality/compression is maybe around dvd quality (?), so not in the same league as modern codecs (but attempting that would start to infringe on patents, so I don't particularly want to go down that route).

Here are two sample video snippets: mattiasgustavsson.com/wasm/fmv.html mattiasgustavsson.com/wasm/fmvdl.h... (both are displayed with my CRT filter, because that's how I am most likely to be using this myself, but it can be toggled with F9).

I tried my hand at making a video codec. I didn't know the first thing about video codecs when I started, so was quite fun to learn about the concepts and how to implement them. I packaged the result in a stb-style, single-file header-only lib, < 2500 loc with no dependencies.

Round a uint32 up to the nearest power-of-two value: gist.github.com/mattiasgusta...

Round a uint32 up to the nearest power-of-two value: gist.github.com/mattiasgusta...

If you're looking for a vector math lib for C (or C++) check it out github.com/mattiasgusta... If you do take a look, please let me know what you think about it - getting feedback is a big part of the reward releasing libraries like this, and I spent a lot of time and effort on it

It's been tested on windows, mac, linux and web-assembly, using msvc, clang, gcc and tcc (tiny c compiler).

It is not trying to be the most optimized library, not using any SIMD intrinsics or assembly code, just straightforward, fully portable, simple implementations of a large number of math functions.

It has a large set of functions, as it attempts to implement most of what you get in shader languages like HLSL and GLSL, and also most of the utility functions from libraries like D3DX in DirectX.

Even though it is primarily designed as a C library, I have also tried to make it fairly nice to use from C++, conditionally adding operator overloads and constructors, but it is not trying to be idiomatic "modern C++" in any way.

Here is the library: github.com/mattiasgusta... Now, you get the best ergonomics if you use it with clang compiler in C11 or later, as it makes (optional) use of C11 _Generics and clang vector type extension, but it doesn't require either to work.

I am excited to share this new single-header C library I have been working on for a while now: vecmath.h, a comprehensive vector/matrix math library for graphics/games/3d. It allows you to write vector math code in C that looks like this:

And I wrote about the inspiration for the Yarnspin engine here: mattiasgustavsson.com/the-adventur...

The engine also includes an editor for adjusting images, implemented using a custom basic imgui system. I've written a bit about it here: mattiasgustavsson.itch.io/yarnspin/dev...

This is what my dev environment looks like when I'm making a game in Yarnspin. I use notepad++, with a custom color scheme, with the "folder as workspace" to get a tree view for both scripts and image files. And with keyboard shortcuts for run/compile and go to error.

The custom script language for Yarnspin is made to be simple, and without a lot of notation or complex syntax. Mostly it's just specifying images and text to display, listing options to choose from and where they lead to

It was made in about a week, using my Yarnspin game engine, which is written in plain C using only stb-style single header libraries github.com/mattiasgusta...

You can play it for free here: mattiasgustavsson.itch.io/neon-lies I think it's one of the best games I've ever made 😀

I'd like to talk a bit about this a game I made, all done in plain C, using only single header libraries, and it runs in the browser too. It's called "Neon Lies" and it's a retro-futuristic cyberpunk story in a William Gibson style setting.

Does the idea of making a game in plain C, without using an off-the-shelf engine, appeal to you, but you don't really know how to go about it? Here's "Repair/Rearm", a game I made using only a handful of single-header libraries, but without an engine,it's just the game code doing only what's needed

I'd like to talk a bit about this a game I made, all done in plain C, using only single header libraries, and it runs in the browser too. It's called "Neon Lies" and it's a retro-futuristic cyberpunk story in a William Gibson style setting.

"dos-like" is a mini-engine/framework I made a couple of years ago. It makes it easy to make games and other things with a 90s MS-DOS look and feel, but using a modern C compiler and running on Windows, Linux, macOS and in the browser using WebAssembler.

Here is one of the first single-header libs I wrote, for reading and writing .ini files github.com/mattiasgusta... I like .ini files because they are so simple and easy to understand and edit even for non-technical people. Sure, they are not as capable as, say, json/xml. That's ok.

Here is another small single-header library that I use all the time: frametimer.h In the basic case, it just measures the delta time between frames, using high precision timers on all platforms. But, it can also lock to a specific fps, and uses very high precision timers to wait

Updated my app.h C library to support standard gamepads, for both windows, osx/linux and wasm. There's a web build here for trying it: mattiasgustavsson.com/wasm/gamepad... Library can be found here: github.com/mattiasgusta... I also updated the app.h template project: github.com/mattiasgusta...

My app.h library is sorely missing gamepad support. But not for long 🙂

Know what’s great? Good old .ini files. Very easy to understand and edit, even for non-programmers. Here’s my single-header C library for reading and writing .ini files. One of the first single header c libs I wrote, and I still use it all the time 🙂 github.com/mattiasgusta...

For those of us who still do software rendering, these alpha-blending tricks are still useful 🙂 gist.github.com/mattiasgusta...

Here’s a small single-header C library for generating pseudo-random numbers. It includes four different rng’s, including PCG and WELL, with a consistent API. They all expose internal state for easy saving and restoring of state. github.com/mattiasgusta...