FA-52410 / Raster memory layout / Member archive

Indexed Nibble Records: Image payload begins at palette or loses relocation · case 05

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

Member previewVariant 5 · 3 implementations · 6 checks per implementation

Case contract

An indexed image has a palette of three-byte entries, a two-byte palette-count field, and high-nibble-first pixels. Each scanline starts with a one-byte checksum. Odd final low nibbles are padding. 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": 95, "byte_address": 86, "image_origin": 85, "keep_mask": 15, "packed_bytes": 4, "palette_bytes": 29, "row_pitch": 5, "shift": 4, "tail_mask": 255, "written_byte": 83}`	`{"allocation_end": 124, "byte_address": 115, "image_origin": 114, "keep_mask": 15, "packed_bytes": 4, "palette_bytes": 29, "row_pitch": 5, "shift": 4, "tail_mask": 255, "written_byte": 83}`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.