FA-87764 / Collision detection broadphase / Member archive

Boxes starting at the same x are paired by both passes · case 04

Pairs with equal minimum x are reported twice.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

solve(A, B): bipartite box pruning (dynamic set A vs static set B), boxes [id,minx,miny,maxx,maxy], closed intervals. Sort both by (minx,id). Pass 1: for each a, B boxes with minx in [a.minx, a.maxx]; pass 2: for each b, A boxes with minx in (b.minx, b.maxx]; y overlap required. Return sorted [a id, b id] pairs.

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	`[[8, 35], [8, 35], [9, 35], [9, 35]]`	`[[8, 35], [9, 35]]`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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