FA-52082 / Raster memory layout / Member archive

Mip Chain Directory: Mip payload origin ignores header or counts it per scanline · case 02

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

Member previewVariant 2 · 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 1	`{"allocation_end": 264, "directory_size": 8, "heights": [5, 3, 2, 1], "level_offsets": [8, 156, 210, 235], "level_origin": 26, "level_sizes": [148, 54, 25, 11], "payload_origin": 26, "row_pitches": [29, 17, 11, 8], "selected_size": 148, "widths": [9, 5, 3, 2]}`	`{"allocation_end": 264, "directory_size": 8, "heights": [5, 3, 2, 1], "level_offsets": [8, 156, 210, 235], "level_origin": 26, "level_sizes": [148, 54, 25, 11], "payload_origin": 29, "row_pitches": [29, 17, 11, 8], "selected_size": 148, "widths": [9, 5, 3, 2]}`	Failed

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