4.1 KiB
Wall thickness — the spec
Status: implemented / evolving (post beta.4 redesign). Visual reference: docs/assets/wall-thickness-reference.png (look at wall bodies only).
Owner intent: thick walls form one continuous hatched body (seamless L and T), grow both ways from the room centreline, fills/light stay inside the inner contour, displayed area is the clean floor, and sun wedges start at the two room-side corners of an opening.
Code: src/wall-thickness.ts, render in src/houseplan-card.ts /
src/space-render.ts. Sun: src/sun.ts. Tests: test/wall-thickness.test.mjs,
demo/smoke_wall_thickness.mjs.
1. Model
Per space: walls: [{ key, cm }]. Key = quantised midpoint + direction
(modulo 180°). Config always stores centimetres. Open boundaries refuse
thickness. One physical stretch has one thickness (atomic collinear spans when
neighbours overlap only partially).
Degrade unmatched keys silently on write. Resize / undo / scale re-key all
touched spans in the same transaction and keep walls in the resize snapshot.
2. Growth (centreline ±½)
Every thick wall grows half outward and half inward from the polygon edge
(outer and shared alike). Silhouette is wider than the polygon by cm/2 on
outer walls. Paper and the content frame grow under that outer half.
3. Body render
Production body is the ring outset(poly, half) − inset(poly, half) per
room, unioned across rooms so shared and T junctions show one continuous
body with no internal seams (as in the reference plan). The body is painted in
two layers: a solid fill from global settings.fill_colors.wall_fill (default
opaque white, with its own opacity) under the diagonal hatch whose stroke
matches the wall outline. Normally neither replaces the other. When the body is
thinner than 3 CSS px on screen, the shared full/static render policy suppresses
only the hatch so it does not collapse into noise; the solid fill remains. Mitre
joins; bevel when the mitre spike exceeds MITRE_LIMIT × thickness.
Openings cut the body full-depth; jambs cap the cut; window glass mid-tunnel; door swing from the inner face. Association uses wall direction ≈ opening angle (mod 180°), then nearest span — never a perpendicular neighbour at a T.
4. Floor, fills, light, area
- Inner contour =
inset(poly, half[]). - Room fills and glow are clipped to the inner contour (not painted into the wall hatch).
- Displayed m² = area of the inner contour (clean floor). Wall-length rulers and opening anchors stay on the centreline.
- With no thickness, inner = poly (parity with pre-thickness behaviour).
5. Sun
Wedges do not draw through wall bodies. Their full source span is translated
from the centreline by half the wall depth along the receiving room's inward
normal, so both side rays begin at the two room-side corners of the window
opening. Clip to the receiving room's inner contour. d = 0 keeps the previous
centreline/full-span wedge. hide_openings hides the symbol only.
6. Tool / hooks / i18n
Plan-editor tool «Wall thickness»; hover whole wall; cm/in from HA; empty/0
clears; apply-to-room. Hooks: data-hp="wall". i18n en/ru.
Draw with thickness. The Draw toolbar carries a session thickness field (default 15 cm, or inches when HA is imperial). Closing a new room outline writes that cm onto every new edge that does not already have one; shared stretches that already carry a neighbour's thickness are left alone. Empty / 0 leaves the room thin. Live thick preview follows the rubber-band while drawing. Split does not use this field. The Wall thickness tool remains for later edits.
7. Out of scope
Decor-line thickness, per-side finish, auto-from-backdrop, plan-wide default.
8. Testing
Unit: ring closed at corners; half-out; inner area; atomic partial shared;
angle-aware opening; rekey after edge/scale. Browser: seamless frame; fill not
in hatch; m² drops with thickness; real resize/undo keeps walls; sun starts at
the room-side opening corners; nav mode restores after can_write; a 1 cm body
uses solid-only in both full and static cards while a 20 cm body keeps its hatch.