FA-87457 / Collision detection broadphase / Member archive

BVH traversal prunes nodes that only touch the query on x · case 02

Queries flush against an object edge return nothing.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

solve(nodes, q): BVH nodes [minx,miny,maxx,maxy,left,right,leaf_id], leaves have left=-1; root is node 0. Stack traversal tests every popped node against the closed query box (counting each test) and descends only into overlapping internal nodes. Return [sorted leaf ids overlapping q, number of node tests].

Why this case matters

Broadphase stages decide which object pairs ever reach narrowphase; a wrong boundary, ordering or bookkeeping rule silently drops real contacts or floods the solver with false candidates.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
case 0	`[[], 3]`	`[[], 5]`	Failed

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