Save the Fold — engineering notes

music --from-seed

The soundtrack is compiled, not composed.

The music library takes a seed and produces a complete multi-track song — melody, harmony, rhythm, structure — as pure note-and-timing data, across 28 musical genres. Generation happens at load and transition time, never on the audio thread; the audio callback only ever pulls frames that already exist.

It is fully deterministic and reproducible: the same seed produces the same song on every machine and every build. That guarantee is enforced all the way down to strict floating-point semantics (/fp:strict) — the same discipline you want in any system where "it reproduced" matters more than "it usually works."

synth --from-hardware-specs

Instruments built from scratch, tested like hardware.

The note data becomes sound through an independent audio-processing library of original synthesizer instruments — modeled on classic hardware and textbook DSP, built from hardware documentation, service manuals, and published papers.

pure function core

The instrument library is render(events) → frames — no UI, no file I/O, no audio device, zero dependency on the game's frameworks. Composition and rendering are fully independent static libraries.

three test tiers

Exact spec tests where references publish numbers; DSP property tests (FFT response vs. theory, envelope timing, NaN/denormal/silence, click-free gating); and rendered-phrase measurement baselines checked into git, failing the build on drift.

ship --single-exe

Shipping discipline.

Production polish — 12 localizations, 185 achievements, keyboard/mouse/gamepad support, a sample-based fallback audio path for lower end hardware.
Modern toolchain — C++23 modules, MSVC, CMake, vcpkg manifest mode, static triplet, one self-contained executable. AddressSanitizer build config maintained alongside the shipping build.
Built agentically — developed with AI-assisted workflows (disclosed on the store page), directed and reviewed with senior-engineer rigor. This project is my working proof that agentic development ships complete, disciplined software fast.
Third-party software — all licensed third-party software is properly attributed in compliance with their licenses. The project made use of Abundant Music by Per Nyblom, SFML, zlib, TinySoundFont, the FluidR3 SoundFont by Frank Wen, JSON for Modern C++, and the Asian DreamZ SoundFont by DSK Music (Victor Castilla), used with the author's permission — each attributed per its license's requirements in the notices that ship with the game.

why-it-matters --for-your-team

Determinism under strict floating point, license compliance, audio-thread safety, measurement-based regression testing — none of that is game trivia. It is the same engineering that protects an enterprise platform processing millions of transactions a day, which is where I spent the last decade. Save the Fold is simply that engineering, in a form you can download and play.