FA-52655 / Raster memory layout / Member archive

Xor Bank Swizzle: Banked tile y uses local row or square footprint · case 05

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

Member previewVariant 5 · 3 implementations · 6 checks per implementation

Case contract

A stipulated 8x4 tile has four banks. Bank = (local x modulo 4) XOR (local y modulo 4); each bank stores two columns per row and begins with a one-byte tag. Tile rows include a seven-byte trailer. 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	`{"address": 1025, "bank": 3, "bank_local": 4, "bank_pitch": 49, "tile_columns": 2, "tile_origin": 853, "tile_pitch": 196, "tile_row_pitch": 399, "tile_x": 0, "tile_y": 2}`	`{"address": 227, "bank": 3, "bank_local": 4, "bank_pitch": 49, "tile_columns": 2, "tile_origin": 55, "tile_pitch": 196, "tile_row_pitch": 399, "tile_x": 0, "tile_y": 0}`	Failed

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