Hello,

Circuit Artist is a game about drawing digital circuits as pixel art — like MS Paint, but pixels are wires and little triangles are NANDs. Hit play and the simulation runs in real time. It's fully white-box: every wire's state is visible.

I launched it last year with a unit-delay simulation that ran until convergence on each update. It worked, but I realized it had some fundamental problems:

(i) It hid what was actually happening. Players couldn't tell the difference between a ripple carry adder and a look-ahead adder — everything just resolved instantly.

(ii) Design bugs became "game bugs." When players had non-converging wires (like A = not(A)), the game couldn't explain why or where the error was.

(iii) Layout didn't matter. A NAND on one side of the map would instantly propagate to the opposite side, making spatial decisions meaningless. Unit delay probably works better for schematic-based simulators like Logisim, not a layout-focused game like this.

(iv) Propagation visualization couldn't be added on top of the unit-delay engine — there was no notion of direction or distance.

So I rebuilt the engine with variable-delay event-based simulation using an adaptation of Elmore delay. The delay for each wire depends on distance and fanout — longer wires are slower, higher fanout adds delay, branching wires are faster.

For the implementation: I compute Elmore delay over wire trees. Each pixel has resistance and capacitance, with NAND inputs as nodes to account for fanout. For non-tree wire graphs, I build a Dijkstra-based spanning tree (driver as root) and interpolate for edges outside the tree. I calculate the delay for each node and project it back to the image so every pixel has a distance.

This lets me animate propagation with a glow effect during simulation. The shader knows when each wire was triggered, the current time, and the Elmore distance of each pixel, so it resolves state per-pixel in real time.

On top of that:

- Time rewind: the simulation is now delta-based, so players can freeze and scrub backwards to debug. Super useful for cyclic circuits.

- Layers: since timing matters now, I added up to 3 layers. NANDs only go on the bottom layer, upper layers propagate faster (lower capacitance). Lets you route wires above dense NAND areas.

The game has a campaign for learning from scratch, though it's still incomplete and in progress. I'm working toward Steam Workshop support so people can create their own campaigns to teach different concepts or cover more advanced topics.

GitHub (full source): https://github.com/lets-all-be-stupid-forever/circuit-artist

Steam: https://store.steampowered.com/app/3139580/Circuit_Artist/

What a beautiful visualization. I will try this on my electronics loving child, see if it takes.

If at all possible: add resistors and capacitors. With those two added you can make many more interesting circuits (Schmitt triggers, a-stable stuff).

This seems awesome! I wish this had come out a few weeks ago so I had time to tinker with it waiting for the Turing Complete rewrite. I particularly like the implementation of Elmore delay to give some meaning to the spatial layout.

I'm not 100% sold on the bitmap editing style of circuit layout vs something like the automatic wire pathing in Turing Complete though. It's something I'll need to play with to get a real opinion on though.

Purchased to have some fun with this weekend. Thanks for publishing the source as well!

It's kind of like Wireworld, a cellular automaton type, similar to Conway's Life but more oriented to circuits. I always loved these things.

This is nice. I wish I had something like this when was taking Electronics courses. The visual component would have been very helpful. Merging this with a course on electronics would be a great resource.

Having Elmore delay in this is fantastic - many "proper" educational simulators don't bother with this important aspect. It also forces people to deal with fanout, as you say.

Plus it looks really cool with the neon.

What a gem. That seems super fun and I love the Paint aesthetic :)

I've written simulators as a career for more than a decade, and I'm stunned at what a good job you've done. The simulation engine is excellent and the visualization is prettier (and more intuitive!) than any I've ever seen.

Oh wow, this is such a great project! I love how we can elegantly simulate propagation <3 Congratulations, I will defiantly purchase it from stream just to help it's development.

Love the aesthetic, even more, that you published the source! I bought a copy on Steam, thank you for your work!

Any plans to add more advanced campaigns, say, to build up to a simple processor?

Beautiful work on an interesting subject!

Holy moly.