Three defects, two of them invisible to every case I had run.
An image alone in a layer failed validation. The texture pipeline never
bound group 1, and every earlier case happened to have a rect in the
same layer, which left one bound from the primitive draw -- so the bug
was hidden by the tests passing.
A `min_binding_size: None` binding takes its minimum from the first
pipeline built against that bind group layout, so one shared group 1
layout held every primitive to the largest. Rect and glyph coexisted
only because glyph is the bigger of the two; the texture slots, at four
bytes, did not. Each primitive now gets its own layout with its entry
size stated, which is also why `PrimitiveRegistry` records the stride.
Because the pipeline layouts now differ per primitive, a pipeline change
drops the bound groups, so group 2 moves after `set_pipeline`.
An empty list still built a bind group over a buffer too small for one
entry, which the stated minimum would now reject. It gets no bind group,
and nothing draws it.
Also from the read-through: `UiRenderNode` kept a `Device` beside the
one `update` is handed, `PrimitiveRegistry::default` registered inside
an `assert_eq!`, and `mask_idx` was an unqualified integer varying where
`idx` beside it was `flat`.
iris
a08f61a80c