A `Primitive` now carries its own WGSL, and `PrimitiveRegistry` keys ids by
`TypeId`, so `Painter::primitive` takes only the value and the `RECT`,
`GLYPH` and `TEXTURE` constants are gone. Registering is what a first draw
does; the built-ins are seeded up front so first-draw order cannot decide
anything about them.
What a primitive samples is no longer something every registration states.
The glyph atlas and the one sampler moved into the shared group, which is
where a mask texture would go too, so a rect's pipeline has no texture in
its layout at all. Only a primitive whose type sets `TEXTURE` gets an image
group, and that is also what records the slot at write time -- so nothing
reads a `u32` back out of the instance payload.
Verified on the headless rig: the tabs example, two images added at runtime,
an image alone in a layer, and text spanning a four-layer atlas after the
array grew twice.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
irisandClaude Opus 5
29d390da52