Blog post: if an AI is going to hallucinate incorrect things about my web site, maybe I should change my site so that it's correct ;) www.redblobgames.com/blog/2025-09... More seriously, it's remarkably good at hallucinating things about my site that are *plausible*. Scary, but also maybe useful.

invest in understanding permalink: wizardzines.com/comics/inves... from our free zine "So you want to be a wizard": wizardzines.com/zines/wizard/

New colors without shooting lasers into your eyes dynomight.net/colors/

bash tricks permalink: wizardzines.com/comics/bash-... from our zine "Bite Size Command Line": wizardzines.com/zines/bite-s...

Weekend project: writing a simple search engine. Part 2 is about document ranking: www.redblobgames.com/blog/2025-08...

Weekend project: building a (site) search engine www.redblobgames.com/blog/2025-08... just for fun! :)

It’s a computational notebook, where all cells are running all the time. Fascinatingly, the UI is the code, adorned with small widgets. I think legibility could be improved for other users, but this points to possibilities in other domains.

anatomy of a http request permalink: wizardzines.com/comics/anato... from our zine "HTTP: Learn your browser's language!": wizardzines.com/zines/http/

Congratulations to Caves of Qud! Award ceremony: www.youtube.com/watch?v=py7M...

how your terminal handles mouse clicks wizardzines.com/comics/the-m... (from "The Secret Rules of the Terminal", which is out now! wizardzines.com/zines/terminal)

Video games also use classical AI rather than genAI— pathfinding (including A*), state machines, constraint solvers (including WFC), utility systems, behavior trees, blackboards, tree search (minimax, alpha/beta), heuristic functions, planning (GOAP and others), cooperative & adversarial approaches…

oh shit! I did something terribly wrong, does git have a magic time machine? permalink: wizardzines.com/comics/oh-sh... from our zine "Oh shit, git!": wizardzines.com/zines/oh-shi...

I just finished the first pass at a procedural landscape generator for a flying game, Kerosene Thunder. The goal is realistic 1960s landscapes ~1000km across, at 500m resolution. This is a thread about how it works now. #procgen #textmode

matklad.github.io/2025/07/16/f... convinced me to try the "font-size-adjust" feature — it's now live on redblobgames.com . I'm using it to to keep the body text and code (monospace) text matched. caniuse.com?search=font-... shows Firefox (partial) support started in 2008, Chrome in 2024.

The terrain above is based on an erosion noise implemented by clayjohn and Fewes in this Shadertoy: www.shadertoy.com/view/7ljcRW It's really impressive, more people doing terrain generation should know about it! #ProcGen

Max Brodeur just presented our paper on smooth rolling knots at the Bridges Conference on Mathematics and the Arts. Max worked on this topic during his semester project together with Michele Vidulis and Liliane-Joy Dandy. More info here: go.epfl.ch/smooth_rolli...

what's a shell? permalink: wizardzines.com/comics/shell/

I wrote this article explaining algorithms for physarum-style simulations bleuje.com/physarum-exp...

How I've learned to build software quickly: - Know how good your code needs to be for the task at hand. - Start with a rough draft. - Try to soften requirements. - Make small changes. - Practice specific skills, like reading code and scripting. More details: evanhahn.com/how-i-build-...

debugging tip: change one thing at a time permalink: wizardzines.com/comics/chang...

I built this demonstration of how an LSP server might facilitate bidirectional editing for code-based CAD tools after reading @kevinlynagh.com's recent musings about the topic.

Devastated to report I read the docs and learned everything I needed to

not sure when that happened but mathematical education videos are really good these days. in the past it used to be 3b1b for precise stuff and some more pop channels for intuition/history but now i feel like even precise stuff has good and approachable treatment. really a golden age

dear imgui 1.92 released! github.com/ocornut/imgu... New protocol for backends to create/update textures, with support for 13 renderers. Dynamic font scaling. Dozens of font/atlas related changes. Dozens of other changes. Expect some turbulence. (misc video from January...)

Failed experiment in tectonic plate collision. I was trying to do something quick&easy but it didn't work as well as I had hoped. www.redblobgames.com/x/2319-mapge... If none of my experiments fail, I'm not being ambitious enough. So I'm ok with having many failures. This was a fun experiment.

Michael Caine: Ducks look calm as they glide along the surface of the water but they're paddling like hell underneath. When you're doing your preparation right, it sometimes looks so good that people watching you make the mistake of assuming it's all...effortless. In my experience, it never is.

I've still never gotten into `fzf` (and maybe I never will!) but I think it's really cool that you can use a fzf 1-liner to make things like this little UI for reviewing git commits jvns.ca/til/fzf-prev...

While reviewing my mapgen4 rendering code, I realized I could render rivers in a much simpler way. The output isn't quite the same though. Left: old, right: new.

Malleable software: Restoring user agency in a world of locked-down apps www.inkandswitch.com/essay/mallea...

“I think interactive diagrams have a lot of potential -- they're not something that classrooms or books really bring to people.” —me, to a friend, in 2006

If you are in a mood for helping you can update your Dear ImGui app to `dynamic_fonts` branch this week-end and write/share all your thoughts/feedback there: github.com/ocornut/imgu... If all goes well : merge to main soon, create a new unpolluted thread for collecting feedback.

While reviewing my mapgen4 rendering code, I realized I was using 'nearest' filtering for the biome colors. What happens if I use 'linear'? (a) I get some river valleys shaded in, even where rivers have dried out (b) I get smoother colors in the oceans (added it to a list of future investigations)

While reviewing my mapgen4 geometry code, I noticed a parameter that I had hard-coded instead of exposing through sliders. I took screenshots of it at 1.00, 0.95, 0.90, 0.85, and added it to the todo list.

It's been a while since I've written about the innards of @compiler-explorer.com. xania.org/202506/how-c... has the details, some statistics and some fun war stories.

Today, working on the Delaunator guide. 1. what it looks like now - point and triangle diagrams showing a *subset* of the data 2. new version - diagrams showing *complete* data including edge cases 3. complete example, with code you can copy/paste, and numbers you can see in the diagram

I've been looking into vertical align of text. Yes, it's complicated (confusingly convoluted) as anything else in the text layout and rendering world. This is great write up on the topic (and very timely for me!) wolthera.info/2025/04/goin...

copy and paste in the terminal wizardzines.com/comics/copy-... (link to the pbcopy script: wzrd.page/pbcopy)

Wanted to compare two folders to see what files were different (unity build succeeded in one and failed in the other). Ran in bash: diff <(cd folder1; find . -type f -print0 | xargs -0 md5sum | sort) <(cd folder2; find . -type f -print0 | xargs -0 md5sum | sort) Presto, found the likely culprit.

New on the blog: "Planetfall," in which I go into great detail about making a fun map based upon a 1999 computer game. One of the most technically demanding projects of my career, for a very niche audience. somethingaboutmaps.wordpress.com/2025/05/20/p... #SMAC

Have you ever scanned a dirty or crumpled up QR code, *certain* it wouldn't work, and then it instantly does? They're built to be really resilient! Here's a guide I put together, full of interactive visuals to show the design choices in the QR spec. perthirtysix.com/how-the-heck-do-qr-codes-work

New blog post: Using flow field pathfinding on a voronoi procedurally generated map to simulate 20,000 traders moving around www.redblobgames.com/blog/2025-05...

Have you ever wished the browser would look at a background color and pick black or white for the text — whichever one provides more contrast? Now, the `constrast-color()` function in CSS does just that. webkit.org/blog/16929/c...

My survey article on line drawing algorithms, pitched for game developers jcd.pub/2025/04/10/t... #gamedev #math #geometry #lines

A wonderful visualization for those of us obsessed by sunlight and geography!

The information density on weatherspark is amazing. The icons on this map are a year's worth of weather data. Left to right on the icon is Jan to Dec. Bottom to top is hours of the day. Each pixel color tells you temperature (blue = cold, red = hot). weatherspark.com/map?pageType...

Working on a blog post, making many diagrams, throwing out many diagrams to simplify the post. This is one that I'm throwing out.

So I finally figured out what's the deal with these quilts

Published my WebGPU Particle Life simulation online! Obviously it requires WebGPU support, and it's quite resource-demanding, so I've set the particle count to 64k for now. Also it probably doesn't work on mobile; will fix later. Enjoy: lisyarus.github.io/webgpu/parti...

Variable Rewards are remarkably powerful. Sometimes, you get something good. Sometimes, you get nothing. But every so often, it's something amazing. That unpredictability keeps us coming back. Life has intermittent variable rewards. Please don't use them for evil.