The user's re-gate refuted the scissor fix as THE strip (6c4b6d6 was a
real but sub-pixel under-coverage): the strip survived, screenshot at a
doorway, full width of the opening, top edge only, "very subtle".
Root cause (pinned by Issue130DoorwayStripTests.UnliftedGate_*): the
+0.02 m shell render lift. Cell shells DRAW 2 cm above the dat origin
(z-fight vs coplanar terrain); f35cb8b (the #119-residual fix,
2026-06-11) deliberately reverted the VISIBILITY graph to the physics
(unlifted) transform - but the OutsideView color gate (terrain/sky/
scissor through the doorway) and the seal/punch depth fans are
DRAW-space consumers and kept projecting the unlifted polygons. The
drawn lintel therefore sits one lift-projection above the gate's top
edge - measured 6.7 px at a 2.4 m doorway - and that band never
receives terrain/sky color while the seal also stamps 2 cm low.
A regression from f35cb8b, NOT from the W=0 clip port (987313a stays
exonerated). Vertical aperture edges are immune (the lift slides them
along themselves) - top edge only, exactly as reported; explains the
"also NOW" timing precisely.
Fix - draw space draws lifted, visibility stays physics (the f35cb8b
invariant, now symmetric):
- PortalVisibilityBuilder.Build gains drawLiftZ: the exit-portal branch
projects the OutsideView region with the lifted transform; flood
admission, side tests, and CellViews are untouched (default 0 keeps
every existing visibility test bit-identical).
- The seal/punch fans (DrawRetailPViewPortalDepthWrite) lift their
world verts to the drawn shell's space.
- One shared constant PortalVisibilityBuilder.ShellDrawLiftZ feeds the
shell registration (GameWindow:5604), the gate, and the fans.
Register: AP-32 ADDED - the +0.02 lift had NO row (a pre-register
deviation the 2026-06-12 sweep missed). The row records the split
invariant both ways: a draw-space consumer that forgets the lift
re-opens the #130 strip; a visibility consumer that picks the lifted
transform re-opens the #119-residual side-cull.
Pins: the lifted gate covers the drawn (lifted) aperture to 0.00 px
across the 147-combo sweep; the unlifted gate shows the 6.7 px strip
(sensitivity proof - if the lift is ever removed, this test says the
drawLiftZ plumbing can go too).
Suites: App 257+1skip / Core 1439+2skip / UI 420 / Net 294 green.
Awaiting the user re-gate at a doorway with the lintel on screen.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The user's "thin strip of background color along the TOP outer edge of a
doorway, looking out from inside" is the landscape-slice scissor box, not
the W=0 clip port.
Mechanism (pinned headlessly, Issue130DoorwayStripTests, 147 eye/gaze
combos at the real Holtburg A9B4 0x0170 exit door):
- BeginDoorwayScissor converted the slice NDC AABB to pixels as
Floor(origin) + Ceiling(size). The far edge floor(min)+ceil(max-min)
lands up to ONE PIXEL SHORT of the true top/right edge at unlucky
fractional alignments (captured: top edge y=0.7938 @1080p -> row 968
cut; right edge column 1296 @1920 cut).
- The scissor brackets the ENTIRE landscape slice (sky, terrain, outdoor
statics, weather). The exit-portal SEAL stamps the full raw aperture at
true depth and the shell wall ends at the aperture edge, so the cut row
never receives any color write -> clear color, flickering with eye
movement as the fractional alignment shifts.
- This violated AD-17's own invariant (over-inclusion is safe,
UNDER-inclusion is the bug class). No register change: the fix restores
the row's documented doctrine.
Lead 1 (987313a W=0 clip port regression) REFUTED by the same harness:
the CPU polygon pipeline (ProjectToClip -> ClipToRegion merges ->
ClipPlaneSet planes) is sub-pixel exact against the raw aperture
projection (worst 0.54 px, 0.00 px aligned). For an all-in-front doorway
polygon the port is bit-identical to the old 1e-4 path by construction.
The EyeInsidePortalOpening rescue stays deleted.
Fix: conservative outer bound floor(min)/ceil(max) extracted to
NdcScissorRect.ToPixels (GL-free; containment property proven in the
header comment); BeginDoorwayScissor delegates.
Pins:
- NdcScissorRectTests: center-inside containment across 251 fractional
alignments x 2 framebuffer sizes + both captured regression cases.
- Issue130DoorwayStripTests: production flood + assembler at the real
exit door; asserts the scissor never cuts a plane-admitted fragment
(worstScissorGap 0.00 px post-fix, was 10.8 px capped) and the CPU
pipeline stays sub-pixel exact (canary 1.2 px).
Suites: App 252+1skip / Core 1439+2skip / UI 420 / Net 294 green.
Awaiting the user visual gate at a cottage doorway.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
