FA-52008 / Raster memory layout / Member archive

Compressed Block Payload: Endpoint and selector segments are multiplied or prefix dropped · case 03

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

Member previewVariant 3 · 3 implementations · 6 checks per implementation

Case contract

A stipulated 4x3 block format stores 5 endpoint bytes followed by twelve one-byte texel selectors. Block rows are padded to a multiple of three blocks; selector lookup never decodes colors. 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": 180, "block_columns": 1, "block_rows": 1, "block_size": 60, "block_start": 33, "block_valid_texels": 1, "padded_columns": 3, "row_pitch": 180, "selector_address": 38, "selector_id": 0}`	`{"allocation": 51, "block_columns": 1, "block_rows": 1, "block_size": 17, "block_start": 33, "block_valid_texels": 1, "padded_columns": 3, "row_pitch": 51, "selector_address": 38, "selector_id": 0}`	Failed

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