Three stages, each a WGSL function with a fixed signature that Horizon calls
inside its own pass: sky (fn sky(input: SkyInput) -> vec4<f32>), material
(fn material(input: MaterialInput) -> Surface) and post (fn post(input:
PostInput) -> vec4<f32>). A stage's WGSL is a generated prelude (the frame
uniform, the stage's structs, its resources in bind group 3, the post
helpers), the pack's shared files, its own file, then the entry points; each
part is located so errors point at the pack's file and line.
The frame is the Rust struct the renderer will upload; its WGSL, its offsets
and docs/api/shaders-reference.md are generated from it, and tests check that
the preludes compile, that naga's layout of the WGSL is the Rust layout, that
the sample pack's stages compile, and that the reference is up to date.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A new crate, horizon-shader-api, reads and checks Horizon's own WGSL shader
packs (docs/api/shaders.md), so the game, the launcher and the registry judge
a pack the same way. This first part is the format: the manifest (id, name,
version, the api line, shared files, the sky, material and post stages,
options typed for WGSL override constants, a GPU time budget) and the package
(a folder or a .hshader zip, built reproducibly so its SHA-256 depends only on
its files). The stages' WGSL is checked in the next parts.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
docs/api/ gets one page per surface other programs build on (mods,
shaders, agent control, servers, the launcher, data formats), each with an
overview measured from the source, the guide, the generated reference, examples,
its stability, what is not there yet and a changelog, plus the policy every
API follows (docs/api/stability.md): a version per API, semver lines,
experimental / preview / stable, deprecation windows, compatibility tests and
the level of every part today.
The website gets a "Build on Horizon" page (website/docs/apis.md) that
summarises them and links the repository's pages.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Ludovic Marie