FA-87784 / Collision detection broadphase / Member archive

Second pass reports pairs as [b, a] · case 04

Consumers index the static set with a dynamic id.

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	`[[1, 6], [1, 35], [6, 2], [7, 1]]`	`[[6, 1], [6, 2], [7, 1], [35, 1]]`	Failed

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