FA-86533 / Procedural level generation constraints / Member archive

BSP dungeon partition: Square regions always split vertically · case 03

BSP layouts are biased to vertical slices.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

Recursively split the rectangle while depth remains. An axis can be split when that side is >= 2*min_size; if neither can, it is a leaf. Split vertically when w > h, or when w == h at even remaining depth; if the chosen axis cannot be split use the other. The first child gets floor(side/2). Returns leaves [x, y, w, h] in left/top-first order.

Why this case matters

Procedural generators silently emit unplayable or unfair levels when a single constraint check uses the wrong boundary, axis, neighborhood or update order; the defect is visible in exact generated geometry.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
regression orientation choice #1	`[[5, 4, 2, 3], [7, 4, 2, 3], [5, 7, 2, 4], [7, 7, 2, 4], [9, 4, 2, 3], [11, 4, 2, 3], [9, 7, 2, 4], [11, 7, 2, 4], [5, 11, 2, 4], [7, 11, 2, 4], [5, 15, 2, 4], [7, 15, 2, 4], [9, 11, 2, 4], [11, 11, 2, 4], [9, 15, 2, 4], [11, 15, 2, 4]]`	`[[5, 4, 2, 3], [7, 4, 2, 3], [5, 7, 4, 2], [5, 9, 4, 2], [9, 4, 2, 3], [11, 4, 2, 3], [9, 7, 4, 2], [9, 9, 4, 2], [5, 11, 4, 2], [5, 13, 4, 2], [9, 11, 4, 2], [9, 13, 4, 2], [5, 15, 4, 2], [5, 17, 4, 2], [9, 15, 4, 2], [9, 17, 4, 2]]`	Failed

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

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