FA-52079 / Raster memory layout / Member archive

Mip Chain Directory: Selected mip origin loses level index or allocation relocation · case 04

The returned physical layout descriptor disagrees with the declared buffer mapping at level_origin.

Member previewVariant 4 · 3 implementations · 6 checks per implementation

Case contract

Store four mip levels consecutively. Each level uses ceil-halving, keeps dimensions at least one, has a two-byte row guard and a three-byte level header. A four-entry directory of two-byte offsets precedes all levels. Return the named intermediate layout descriptor and final address fields; all quantities are integer byte offsets unless explicitly stated.

Why this case matters

Offline raster resource, upload, readback, and storage-layout regression model.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
layout fixture 2	`{"allocation_end": 570, "directory_size": 8, "heights": [6, 3, 2, 1], "level_offsets": [8, 383, 482, 519], "level_origin": 44, "level_sizes": [375, 99, 37, 15], "payload_origin": 47, "row_pitches": [62, 32, 17, 12], "selected_size": 99, "widths": [12, 6, 3, 2]}`	`{"allocation_end": 570, "directory_size": 8, "heights": [6, 3, 2, 1], "level_offsets": [8, 383, 482, 519], "level_origin": 419, "level_sizes": [375, 99, 37, 15], "payload_origin": 422, "row_pitches": [62, 32, 17, 12], "selected_size": 99, "widths": [12, 6, 3, 2]}`	Failed

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