The publisher (SQUARE ENIX) and the 2nd developer/studio splash logo share
one K8888 atlas at physical base 0x4dbee000, sampled at different UVs. The
publisher's white text occupies the top V-bands; the developer logo's
(bluish/gold) artwork is CPU-written into the SAME surface AFTER the publisher
frame, so the atlas evolves across frames.
The UI host texture cache (`texture_cache_host::upload`) only re-uploads a
`TextureKey` when `version_when_uploaded` increases. But the per-draw bind in
`render.rs` hardcoded `version_when_uploaded = 1` for every draw, so once the
atlas was first uploaded (during the publisher frame, with only the top bands
filled) the cache pinned that partial upload. The 2nd logo, sampling a V-band
that was still zero at first-upload time, read transparent-black -> rendered
nothing (the "white-triangle / black stub" the user saw after SQUARE ENIX).
Verdict: (G) a legitimate 2nd LOGO item whose real artwork lives in the same
evolving atlas — NOT a spurious 3rd item, and NOT a geometry/shader/blend gap.
Measured via readback: the 2nd-logo geometry rasterizes correctly (3 on-screen
quads), interp1 (UV) and interp0 (color) reach the PS with real values, the
texture content at the sampled bands exists — only the bound wgpu texture was
the stale partial upload.
Fix (UI-only, deterministic core untouched):
- `gpu_system`: thread the real content `version` (from `span_max_version`)
into `last_draw_textures` (now `(key, version, bytes)`).
- `draw_capture::DrawCapture.textures`: same 3-tuple.
- `render.rs`: use the real `version` (not a hardcoded 1) so the host cache
re-uploads when the guest fills more of the atlas.
- `exports.rs` `vd_swap`: the legacy single-texture `publish_texture` bridge
drops the version (`(key, _v, bytes) -> (key, bytes)`).
Readback (env-gated probe, removed before commit): after the fix the 2nd logo
renders real varied artwork (blue + gold texels in a centered strip) instead
of black. Determinism: `check -n50m --gpu-inline --stable-digest` byte-
identical to the c0c6088 baseline (captured both via git-stash). 686 tests
green. No faking — real decoded texels through the real guest draw.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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