Adds the foundational portal-plane record for cell transition detection.
PortalPlane.FromVertices computes a normalised plane from 3 coplanar
polygon vertices via cross product + dot product; IsCrossing tests whether
a movement vector straddles the plane (strictly negative dot-product
product — exact-on-plane position returns false as specified).
4 new unit tests: normal construction, opposite-side crossing, same-side
no-crossing, start-on-plane no-crossing. All 269 tests green.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Removes all [PLAYER], [PLAYER-INIT], [PLAYER-ANIM] diagnostic dump
lines now that walking, camera, and animation are verified working.
Updates PhysicsEngineTests.Resolve_EnterIndoorCell to match the new
behavior (outdoor→indoor transition disabled in the B.2 MVP): the
test now asserts the player stays outdoor at terrain Z instead of
transitioning to the indoor cell.
265 tests green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Combines TerrainSurface + CellSurface into a single Resolve() API
that handles outdoor terrain walking, indoor floor walking,
outdoor<->indoor cell transitions, step-height enforcement, and
ground detection.
Step-height blocks upward Z deltas exceeding the limit (walls,
cliffs); downhill movement is always accepted. Indoor transitions
pick the cell whose floor Z is closest to the entity's current Z
(handles multi-story buildings). Reports IsOnGround=false when
no landblock or surface covers the entity's position (gravity
applied by the caller).
One API mismatch fixed vs plan: plan encoded the upper 16 landblock
bits into the returned cell ID, but the tests assert the raw cell ID
(0x0100, <0x0100) — so Resolve returns targetCellId directly.
6 new tests covering flat terrain, slopes, step-height rejection,
indoor entry/exit, and void detection. 243 total, all green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Extracts the bilinear heightmap interpolation from GameWindow's
inlined SampleTerrainZ into a reusable class. Also adds outdoor
cell ID computation (8×8 grid of 24-unit cells, 0x0001..0x0040).
First component of the physics collision engine.
6 new tests, all green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Projects an XY point onto a cell's floor polygons via brute-force
triangle iteration + barycentric Z interpolation. Fan-triangulates
quads and larger polygons. Returns null when outside all floor
surfaces. Accepts pre-transformed world-space vertex positions so
the caller handles EnvCell coordinate transforms.
Second component of the physics collision engine.
4 new tests, all green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
