FA-52080 / Raster memory layout / Member archive

Mip Chain Directory: Selected mip origin loses level index or allocation relocation · case 05

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

Member previewVariant 5 · 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": 743, "directory_size": 8, "heights": [6, 3, 2, 1], "level_offsets": [8, 491, 626, 681], "level_origin": 53, "level_sizes": [483, 135, 55, 17], "payload_origin": 56, "row_pitches": [80, 44, 26, 14], "selected_size": 135, "widths": [13, 7, 4, 2]}`	`{"allocation_end": 743, "directory_size": 8, "heights": [6, 3, 2, 1], "level_offsets": [8, 491, 626, 681], "level_origin": 536, "level_sizes": [483, 135, 55, 17], "payload_origin": 539, "row_pitches": [80, 44, 26, 14], "selected_size": 135, "widths": [13, 7, 4, 2]}`	Failed

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