FA-52567 / Raster memory layout / Member archive

Variable Scanline Packets: Directory slot uses byte index or skips first record · case 02

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

Member previewVariant 2 · 3 implementations · 6 checks per implementation

Case contract

Each scanline is a packet with a two-byte tag, a four-byte absolute-offset directory entry, and a caller-specified encoded payload length. The directory precedes packet bytes; a trailing one-byte terminator follows each packet. 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": 65, "directory_bytes": 20, "directory_entry": 19, "packet_origins": [38, 44, 47, 54, 58], "packet_sizes": [6, 3, 7, 4, 7], "payload_end": 46, "payload_start": 46, "relative_offsets": [0, 6, 9, 16, 20], "rows": 5, "terminator": 46}`	`{"allocation_end": 65, "directory_bytes": 20, "directory_entry": 22, "packet_origins": [38, 44, 47, 54, 58], "packet_sizes": [6, 3, 7, 4, 7], "payload_end": 46, "payload_start": 46, "relative_offsets": [0, 6, 9, 16, 20], "rows": 5, "terminator": 46}`	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.