Setup.Spheres were previously coerced to short cylinders (CylHeight=2*r),
which is geometrically wrong: a cylinder has flat caps; a sphere does not.
This ported CSphere::intersects_sphere (0x00537A80) so sphere-typed shadow
entries are tested as spheres — 3-D distance, no height clamping.
Changes:
- ShadowObjectRegistry.cs: added ShadowCollisionType.Sphere (enum value 2).
The BuildFloodSpheres anyCyl dedup at :232 is unaffected: only Cylinder
sets anyCyl=true; Sphere shapes fall through to the BSP-fallback path
(anyCyl=false → included), which is correct.
- ShadowShapeBuilder.cs: FromSetup now emits ShadowCollisionType.Sphere
(CylHeight=0) for Setup.Spheres instead of a short Cylinder.
- CollisionPrimitives.cs: added SweptSphereHitsSphere — quadratic swept
solve ported from ACE Sphere.cs::FindTimeOfCollision, which is a C# port
of retail's CSphere::intersects_sphere @ 0x00537A80. Sign convention
confirmed against the decomp: retail negates the root to produce a
forward t ∈ (0,1].
- TransitionTypes.cs: added Sphere narrow-phase branch between BSP and
Cylinder in FindObjCollisionsInCell; uses 3-D distance for overlap
(not XY-only). Added SphereCollision() method implementing the 3-D
wall-slide response. Updated diagnostic logging at :2734 to cover Sphere.
- Updated ShadowShapeBuilderTests for new Sphere type assertion.
- New SphereIntersectsSphereConformanceTests: 9 geometrically-anchored
cases (head-on, tangent, perpendicular-miss, lateral-near-miss,
sweep-away, beyond-step, degenerate-zero-sweep, already-overlapping,
vertical-sweep).
Retail oracle: CSphere::intersects_sphere @ 0x00537A80 (named-retail);
ACE Sphere.cs::FindTimeOfCollision (C# port, cross-confirmed).
Build: 0 errors, 10 warnings (pre-existing).
Tests: 1576 pass / 0 fail / 2 skip (1578 total).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
