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>
Ludovic Marie
cad817c82d