FA-52083 / Raster memory layout / Member archive

Mip Chain Directory: Mip payload origin ignores header or counts it per scanline · case 03

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

Member previewVariant 3 · 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": 361, "directory_size": 8, "heights": [5, 3, 2, 1], "level_offsets": [8, 221, 290, 321], "level_origin": 35, "level_sizes": [213, 69, 31, 13], "payload_origin": 35, "row_pitches": [42, 22, 14, 10], "selected_size": 213, "widths": [10, 5, 3, 2]}`	`{"allocation_end": 361, "directory_size": 8, "heights": [5, 3, 2, 1], "level_offsets": [8, 221, 290, 321], "level_origin": 35, "level_sizes": [213, 69, 31, 13], "payload_origin": 38, "row_pitches": [42, 22, 14, 10], "selected_size": 213, "widths": [10, 5, 3, 2]}`	Failed

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