Sam Wanuch

A single Rust binary with a plugin framework allowing modules to declare their data storage requirements, and background tasks, using PostgreSQL.

The audiobook pipeline periodically checks webnovel sites for updates, converts them via TTS to audio, then texts me a link to the web player to listen to the latest chapter.

An earlier iteration of this was built on Go. Apart from the rewrite to Rust, and occasional feature work, it has run entirely maintenance free with zero downtime for years. It occasionally texts me alerts when external services are breaking tasks but the system self repairs as fast as the external services do.

Features a custom purpose "which of this set of variables can be true" query, necessary for efficient puzzle generation. Also oriented around being efficient to clone and add new clauses while retaining partially solved state and learned clauses. It may not be a state of the art SAT solver, but those generally aren't exactly WASM compatible.

The kernel provides task creation, scheduling, and message passing; everything else, including the name server and the clock server, runs as ordinary tasks outside it. Send, receive, and reply of a four-byte message takes 2.7 microseconds, and a context switch takes only 0.6 microseconds. For scale, one measurement puts a Linux context switch on a 2012 Xeon at about 1.3 microseconds, on hardware twelve years newer, though Linux is doing far more. My context switch was optimized at the scale of listing out the individual assembly instructions on the hot path, and comparing them to the manual's cycle times per instruction. The only code provided was a deliberately broken serial communication routine; everything else was written in C and assembly without libraries. The train-control half was done with a partner and ended with two trains driving a plotter that printed text and a portrait of the professor.

The scheduler is a task tree: any task can spawn children that must finish before it does, and queue follow-up work to run after. Reflected and refracted rays are child tasks whose colors a final task combines. Any surface property, not just color, can be driven by Perlin noise, and a generated starfield with galaxy-like clouds provides the backgrounds. The rendering code is mine; the Lua scene loader was supplied by the University of Waterloo graphics course it was written for.

• sorrow (Python): the original engine, built for a high school assignment; see Sorrow.
• sorrow (C++) (source): a later iteration moved to C++ using template metaprogramming for type safety and multithreaded staged scheduler.
• starlight (Rust): a more graphics focused 3D forward renderer with a shadow texture array, normal mapping, a sweep-resolve capsule character controller, chunked procedural streaming, and two-player UDP netcode.
• growth (Rust): a playable tank-arena prototype with a proc-macro crate deriving live inspectors.
• crooked (Rust): registration-free implicit components and two thousand rayon-parallel flocking agents.

My high school computer science teacher asked us to form groups to make a game. That seemed too easy so I asked to work alone and make a game engine with two games. She mentioned the difficulty of the games wouldn't matter, since she could just edit the code. I took this as a challenge and added code/data hashing and validation to the engine, forcing it to crash if any modifications were detected.