A pack's `fn material(input: MaterialInput) -> Surface` now gives the lit
colour of every terrain surface: sections and distant tiles, solid,
cutout and translucent, in both the instanced and the flat draws. Terrain
keeps Horizon's meshes, culling and draw lists; only its pipelines change.
Their shader is the pack's stage, a prefixed copy of terrain.wgsl's
terrain section, and entries that hand the pack the texture, the vertex
tint, the light levels and the lightmap's colour apart, then apply the
alpha test and fog as `fs_solid` and `fs_translucent` do.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A pack's `sky` function gets vanilla's colour along each view ray and draws
where the vanilla sky dome draws, under the sun, moon, stars and clouds. The
pipeline's shader is the pack's checked stage (`CheckedStage::source`, new)
followed by a copy of terrain.wgsl's sky with every name prefixed
`horizon_sky_`, so none can meet a pack's; terrain.wgsl's `fs_sky` now calls
`sky_along_ray`, the same code as before.
A running pack is one `NativePack`: the frame every stage reads (written once
a frame), its sky and post stages and its pass timer. In a frame F3 times, the
sky draws in a pass of its own so the overlay can show its time; otherwise it
stays in the world's pass.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A native pack named by HORIZON_SHADER_PACK (a folder with horizon-shaders.toml
or a .hshader in shaderpacks/) is checked, then its post passes run over the
world's own target, the one a shaders/ pack reads: no second target and no
extra pass, and without a pack the frame only tests one Option. The pack is
looked at twice a second; a saved file is checked and rebuilt in place, and a
version that fails is refused in the chat while the last good one keeps
drawing.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The SDK's tool, in horizon-shader-api: `horizon-shader new <dir> --template
post|sky|material` makes a pack that passes the check, `check <pack>...
[--json]` runs the check the game, the launcher and the registry run and
prints each stage's cost and the pack's SHA-256 or every problem at its
file:line:column, and `pack <dir>` checks then writes the reproducible
.hshader. Golden Hour, the example pack, warms the sky around a low sun and
adds a soft glow and a colour grade, with five options. docs/shaders.md is the
authors' guide.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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