fix: make room walls and slabs join cleanly

[wass08]

Summary

• derive slab render boundaries per wall-backed span using the matched wall thickness, with centerline joins for equal rooms and higher-slab ownership for unequal elevations
• compute side-aware, piecewise wall support profiles so stacked, adjacent, partial-span, curved, and holed slabs do not lower or overextend walls incorrectly
• improve wall endpoint splitting, attachment migration, snapping, and automatic slab/ceiling reconciliation around T-junctions and room topology changes
• keep slab boundary reshaping canonical while applying wall-face and sibling joins at render time
• include the branch's KTX2 loader and tree wind transform-order fixes

Test plan

• bun check-types — 10/10 tasks
• bun run build — 7/7 tasks
• focused slab/wall geometry suite — 55 passing tests
• manual validation with stacked slabs, unequal adjacent rooms, partial shared spans, and offset-room wall transitions

Generated with Codex.

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Note

High Risk
Changes core floor/wall elevation and footprint math used by rendering, placement, and wall extrusion, with broad interaction between slabs, holes, curved walls, and undo—mitigated by a large focused test suite but still easy to miss edge layouts.

Overview
Slab footprints are no longer a single uniform outset/inset. getRenderableSlabPolygon now takes level walls and sibling slabs, splits each stored edge into spans, and projects them as interior seams (equal height on centerline; unequal height gives the higher slab the full wall band), wall-backed outer faces, or free geometry. Stored polygons stay canonical; 3D/2D fills, spatial overlap, and dirty-marking all use the same rendered footprint (including slabPolygonContextFromGeometry and a new slab dependency system so meshes refresh when neighbours or walls change).

Wall base height moves from “max overlapping slab elevation + point samples in holes” to computeWallSlabSupport: clip centerline and face polylines against rendered slabs minus holes, pool elevations, require majority support before lifting the whole wall, and emit baseSegments / baseElevation for piecewise bottoms. SpatialGridManager.getSlabSupportForWall delegates here and caches level walls from the scene store.

Editor / nodes: slab edge drags snap the edge onto wall bands (resolveSlabEdgeBandSnap, snapSlabEdgeToWallBand); wall commits and endpoint moves use resolveEndpointWallSplit inside a single undo step; wall chains stop on T-junctions / room close (chainEndJoinsExistingWall); auto slab/ceiling sync demotes orphaned autos or deletes merge leftovers by coverage sampling.

Smaller UX fixes: floorplan Alt/Shift re-applies active drag sessions; polygon resize arrows ignore depth test; 2D wall chaining mirrors 3D auto-close rules.

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Cursor Bugbot has reviewed your changes using high effort and found 4 potential issues.

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Duplicate walls on 2D clicks

High Severity

In 2D-only wall placement, each segment commit still emits grid:click to the 3D wall tool before the panel calls createWallOnCurrentLevel. If that tool handler is still subscribed (same as split view), one click can create two identical walls.

 

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Level wall lists disagree

Medium Severity

3D slab meshes build render polygons from walls whose parentId equals the level, while wall slab support walks the parent chain to the level. Walls not direct level children are omitted from slab seams but still affect wall elevation support.

Additional Locations (1)

• packages/core/src/hooks/spatial-grid/spatial-grid-manager.ts#L1292-L1318

 

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Floor items ignore rendered slabs

Medium Severity

markNodesOverlappingSlab now tests walls against the slab’s rendered footprint, but floor-placed items still use the stored slab.polygon for overlap and dirty marking. When support geometry only grows via wall-band adoption, items in that band may never re-elevate after slab or wall context changes.

Additional Locations (1)

• packages/core/src/hooks/spatial-grid/spatial-grid-manager.ts#L1216-L1221

 

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Curved wall support param mismatch

Medium Severity

computeWallSlabSupport merges normalized support intervals from the centerline and offset face polylines into one [0,1] breakpoint axis, then samples highestAt on every polyline at the same t. On curved walls those polylines have different arc lengths, so a shared t is not the same physical station and piecewise baseSegments can mis-profile the wall base.

 

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