FA-53180 / Raster memory layout / Member archive

Page Split Texel Spans: Texel gather drops second physical span or emits zero-length tail · case 05

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

Member previewVariant 5 · 3 implementations · 6 checks per implementation

Case contract

Raster texels contain six bytes and may straddle 16-byte virtual pages. A virtual byte span maps through a noncontiguous physical page directory; output contains source spans and offsets for reassembling one texel. 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 3	`{"byte_addresses": [223, 224, 225, 226, 227, 228], "destination_offsets": [0, 1], "first_bytes": 1, "first_page": 13, "first_physical": 223, "page_offset": 15, "remaining": 5, "second_physical": 240, "spans": [[223, 6]], "virtual_start": 223}`	`{"byte_addresses": [223, 240, 241, 242, 243, 244], "destination_offsets": [0, 1], "first_bytes": 1, "first_page": 13, "first_physical": 223, "page_offset": 15, "remaining": 5, "second_physical": 240, "spans": [[223, 1], [240, 5]], "virtual_start": 223}`	Failed

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