erik/acdream
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions 1

feat(physics): A4 — CellTransit.FindCellSet overload exposes candidate set

Browse source 
Refactors FindCellList to delegate to a private helper
(BuildCellSetAndPickContaining) that returns BOTH the containing cell
id AND the full candidate HashSet. Public surface gains a new
FindCellSet overload; existing FindCellList behavior is unchanged.

Used by the upcoming Transition.CheckOtherCells (Phase A4) to iterate
every cell the sphere overlaps for per-cell BSP collision. Mirrors
retail's CObjCell::find_cell_list filling both cell_array AND var_4c
at acclient_2013_pseudo_c.txt:272725.

Three new unit tests cover sphere-fully-inside-primary,
sphere-straddling-portal, and outdoor-seed-neighbour-landcells cases.

Spec: docs/superpowers/specs/2026-05-20-phase-a4-multi-cell-bsp-design.md
Plan: docs/superpowers/plans/2026-05-20-phase-a4-multi-cell-bsp.md

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
Erik 2026-05-20 16:11:31 +02:00
parent a8a0366eb1
commit e6369e266f
2 changed files with 180 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

45
src/AcDream.Core/Physics/CellTransit.cs
View file

@ -223,7 +223,8 @@ public static class CellTransit
/// finds the cell whose <see cref="CellPhysics.CellBSP"/> contains
/// the sphere center, and returns its full id (landblock-prefixed).
/// Falls back to <paramref name="currentCellId"/> when no candidate
/// matches.
/// matches. The candidate set built internally is discarded; use
/// <see cref="FindCellSet"/> to recover it.
/// </para>
///
/// <para>
@ -238,7 +239,47 @@ public static class CellTransit
float sphereRadius,
uint currentCellId)
{
var candidates = new HashSet<uint>();
return BuildCellSetAndPickContaining(
cache, worldSphereCenter, sphereRadius, currentCellId,
out _);
}
/// <summary>
/// Phase A4 (2026-05-20). Same portal-graph traversal as
/// <see cref="FindCellList"/> but additionally returns the full
/// candidate set built during traversal. Used by
/// <see cref="Transition.CheckOtherCells"/> to iterate every cell
/// the sphere overlaps for per-cell BSP collision.
///
/// <para>
/// Retail oracle: <c>CTransition::check_other_cells</c> at
/// <c>acclient_2013_pseudo_c.txt:272717-272798</c> calls
/// <c>CObjCell::find_cell_list(&amp;this-&gt;cell_array, &amp;var_4c, ...)</c>
/// which fills both the cell_array (set) and var_4c (containing cell).
/// </para>
/// </summary>
public static uint FindCellSet(
PhysicsDataCache cache,
Vector3 worldSphereCenter,
float sphereRadius,
uint currentCellId,
out IReadOnlyCollection<uint> cellSet)
{
var containing = BuildCellSetAndPickContaining(
cache, worldSphereCenter, sphereRadius, currentCellId,
out var candidates);
cellSet = candidates;
return containing;
}
private static uint BuildCellSetAndPickContaining(
PhysicsDataCache cache,
Vector3 worldSphereCenter,
float sphereRadius,
uint currentCellId,
out HashSet<uint> candidates)
{
candidates = new HashSet<uint>();
uint currentLow = currentCellId & 0xFFFFu;
if (currentLow >= 0x0100u)