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FA-52021 / Raster memory layout / Open access

Compressed Block Payload: Selector ordering is transposed or assumes square blocks · case 01

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

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Selector ordering is transposed or assumes square blocks The faulty expression is (p["x"]%4)*3+p["y"]%3.

THE FAILURE

Selector ordering is transposed or assumes square blocks The faulty expression is (p["x"]%4)*3+p["y"]%3.

Unsuccessful approach: The attempted repair uses (p["y"]%4)*4+p["x"]%4 and still violates the layout contract.

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.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(p):
    p = dict(p)
    block_columns = (p["w"]+3)//4
    block_rows = (p["h"]+2)//3
    padded_columns = ((block_columns+2)//3)*3
    block_size = p["endpoints"]+12
    row_pitch = padded_columns*block_size
    block_start = p["base"]+(p["y"]//3)*row_pitch+(p["x"]//4)*block_size
    selector_id = (p["x"]%4)*3+p["y"]%3
    selector_address = block_start+p["endpoints"]+selector_id
    allocation = row_pitch*block_rows
    block_valid_texels = min(4,p["w"]-(p["x"]//4)*4)*min(3,p["h"]-(p["y"]//3)*3)
    return {'block_columns': block_columns, 'block_rows': block_rows, 'padded_columns': padded_columns, 'block_size': block_size, 'row_pitch': row_pitch, 'block_start': block_start, 'selector_id': selector_id, 'selector_address': selector_address, 'allocation': allocation, 'block_valid_texels': block_valid_texels}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {1: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 11, 'selector_id': 0, 'selector_address': 16, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 6, 'h': 4, 'x': 1, 'y': 2, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 2, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 11, 'selector_id': 9, 'selector_address': 25, 'allocation': 102, 'block_valid_texels': 12}), ({'w': 10, 'h': 8, 'x': 8, 'y': 6, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 3, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 147, 'selector_id': 0, 'selector_address': 152, 'allocation': 153, 'block_valid_texels': 4}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 266, 'selector_id': 7, 'selector_address': 278, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 18, 'h': 10, 'x': 16, 'y': 8, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 5, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 283, 'selector_id': 8, 'selector_address': 296, 'allocation': 408, 'block_valid_texels': 6}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 215, 'selector_id': 3, 'selector_address': 223, 'allocation': 255, 'block_valid_texels': 4})], 2: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 22, 'selector_id': 0, 'selector_address': 27, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 7, 'h': 5, 'x': 1, 'y': 2, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 2, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 22, 'selector_id': 9, 'selector_address': 36, 'allocation': 102, 'block_valid_texels': 12}), ({'w': 11, 'h': 9, 'x': 8, 'y': 6, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 3, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 158, 'selector_id': 0, 'selector_address': 163, 'allocation': 153, 'block_valid_texels': 9}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 277, 'selector_id': 7, 'selector_address': 289, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 19, 'h': 11, 'x': 16, 'y': 8, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 5, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 294, 'selector_id': 8, 'selector_address': 307, 'allocation': 408, 'block_valid_texels': 9}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 226, 'selector_id': 3, 'selector_address': 234, 'allocation': 255, 'block_valid_texels': 4})], 3: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 33, 'selector_id': 0, 'selector_address': 38, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 8, 'h': 6, 'x': 1, 'y': 2, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 2, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 33, 'selector_id': 9, 'selector_address': 47, 'allocation': 102, 'block_valid_texels': 12}), ({'w': 12, 'h': 10, 'x': 8, 'y': 6, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 4, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 169, 'selector_id': 0, 'selector_address': 174, 'allocation': 204, 'block_valid_texels': 12}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 288, 'selector_id': 7, 'selector_address': 300, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 20, 'h': 12, 'x': 16, 'y': 8, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 5, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 305, 'selector_id': 8, 'selector_address': 318, 'allocation': 408, 'block_valid_texels': 12}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 237, 'selector_id': 3, 'selector_address': 245, 'allocation': 255, 'block_valid_texels': 4})], 4: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 44, 'selector_id': 0, 'selector_address': 49, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 9, 'h': 7, 'x': 1, 'y': 2, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 3, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 44, 'selector_id': 9, 'selector_address': 58, 'allocation': 153, 'block_valid_texels': 12}), ({'w': 13, 'h': 11, 'x': 8, 'y': 6, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 282, 'selector_id': 0, 'selector_address': 287, 'allocation': 408, 'block_valid_texels': 12}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 299, 'selector_id': 7, 'selector_address': 311, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 21, 'h': 13, 'x': 16, 'y': 8, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 6, 'block_rows': 5, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 316, 'selector_id': 8, 'selector_address': 329, 'allocation': 510, 'block_valid_texels': 12}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 248, 'selector_id': 3, 'selector_address': 256, 'allocation': 255, 'block_valid_texels': 4})], 5: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 55, 'selector_id': 0, 'selector_address': 60, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 10, 'h': 8, 'x': 1, 'y': 2, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 3, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 55, 'selector_id': 9, 'selector_address': 69, 'allocation': 153, 'block_valid_texels': 12}), ({'w': 14, 'h': 12, 'x': 8, 'y': 6, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 293, 'selector_id': 0, 'selector_address': 298, 'allocation': 408, 'block_valid_texels': 12}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 310, 'selector_id': 7, 'selector_address': 322, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 22, 'h': 14, 'x': 16, 'y': 8, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 6, 'block_rows': 5, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 327, 'selector_id': 8, 'selector_address': 340, 'allocation': 510, 'block_valid_texels': 12}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 259, 'selector_id': 3, 'selector_address': 267, 'allocation': 255, 'block_valid_texels': 4})]}
for i, (p, expected) in enumerate(cases[N]):
    check("layout fixture " + str(i + 1), solve(p), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
layout fixture 1{'allocation': 51, 'block_columns': 1, 'block_rows': 1, 'block_size': 17, 'block_start': 11, 'block_valid_texels': 1, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 16, 'selector_id': 0}{'allocation': 51, 'block_columns': 1, 'block_rows': 1, 'block_size': 17, 'block_start': 11, 'block_valid_texels': 1, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 16, 'selector_id': 0}Passed
layout fixture 2{'allocation': 102, 'block_columns': 2, 'block_rows': 2, 'block_size': 17, 'block_start': 11, 'block_valid_texels': 12, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 21, 'selector_id': 5}{'allocation': 102, 'block_columns': 2, 'block_rows': 2, 'block_size': 17, 'block_start': 11, 'block_valid_texels': 12, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 25, 'selector_id': 9}Failed
layout fixture 3{'allocation': 153, 'block_columns': 3, 'block_rows': 3, 'block_size': 17, 'block_start': 147, 'block_valid_texels': 4, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 152, 'selector_id': 0}{'allocation': 153, 'block_columns': 3, 'block_rows': 3, 'block_size': 17, 'block_start': 147, 'block_valid_texels': 4, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 152, 'selector_id': 0}Passed
layout fixture 4{'allocation': 306, 'block_columns': 4, 'block_rows': 3, 'block_size': 17, 'block_start': 266, 'block_valid_texels': 8, 'padded_columns': 6, 'row_pitch': 102, 'selector_address': 281, 'selector_id': 10}{'allocation': 306, 'block_columns': 4, 'block_rows': 3, 'block_size': 17, 'block_start': 266, 'block_valid_texels': 8, 'padded_columns': 6, 'row_pitch': 102, 'selector_address': 278, 'selector_id': 7}Failed
layout fixture 5{'allocation': 408, 'block_columns': 5, 'block_rows': 4, 'block_size': 17, 'block_start': 283, 'block_valid_texels': 6, 'padded_columns': 6, 'row_pitch': 102, 'selector_address': 290, 'selector_id': 2}{'allocation': 408, 'block_columns': 5, 'block_rows': 4, 'block_size': 17, 'block_start': 283, 'block_valid_texels': 6, 'padded_columns': 6, 'row_pitch': 102, 'selector_address': 296, 'selector_id': 8}Failed
layout fixture 6{'allocation': 255, 'block_columns': 2, 'block_rows': 5, 'block_size': 17, 'block_start': 215, 'block_valid_texels': 4, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 229, 'selector_id': 9}{'allocation': 255, 'block_columns': 2, 'block_rows': 5, 'block_size': 17, 'block_start': 215, 'block_valid_texels': 4, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 223, 'selector_id': 3}Failed

SHA-256 / 923b1562189d88f0bb123a6c273d1b84d5ee3ed85380ce4ceb0f1ceab9b3947d

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(p):
    p = dict(p)
    block_columns = (p["w"]+3)//4
    block_rows = (p["h"]+2)//3
    padded_columns = ((block_columns+2)//3)*3
    block_size = p["endpoints"]+12
    row_pitch = padded_columns*block_size
    block_start = p["base"]+(p["y"]//3)*row_pitch+(p["x"]//4)*block_size
    selector_id = (p["y"]%4)*4+p["x"]%4
    selector_address = block_start+p["endpoints"]+selector_id
    allocation = row_pitch*block_rows
    block_valid_texels = min(4,p["w"]-(p["x"]//4)*4)*min(3,p["h"]-(p["y"]//3)*3)
    return {'block_columns': block_columns, 'block_rows': block_rows, 'padded_columns': padded_columns, 'block_size': block_size, 'row_pitch': row_pitch, 'block_start': block_start, 'selector_id': selector_id, 'selector_address': selector_address, 'allocation': allocation, 'block_valid_texels': block_valid_texels}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {1: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 11, 'selector_id': 0, 'selector_address': 16, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 6, 'h': 4, 'x': 1, 'y': 2, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 2, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 11, 'selector_id': 9, 'selector_address': 25, 'allocation': 102, 'block_valid_texels': 12}), ({'w': 10, 'h': 8, 'x': 8, 'y': 6, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 3, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 147, 'selector_id': 0, 'selector_address': 152, 'allocation': 153, 'block_valid_texels': 4}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 266, 'selector_id': 7, 'selector_address': 278, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 18, 'h': 10, 'x': 16, 'y': 8, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 5, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 283, 'selector_id': 8, 'selector_address': 296, 'allocation': 408, 'block_valid_texels': 6}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 2, 'base': 11, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 215, 'selector_id': 3, 'selector_address': 223, 'allocation': 255, 'block_valid_texels': 4})], 2: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 22, 'selector_id': 0, 'selector_address': 27, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 7, 'h': 5, 'x': 1, 'y': 2, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 2, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 22, 'selector_id': 9, 'selector_address': 36, 'allocation': 102, 'block_valid_texels': 12}), ({'w': 11, 'h': 9, 'x': 8, 'y': 6, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 3, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 158, 'selector_id': 0, 'selector_address': 163, 'allocation': 153, 'block_valid_texels': 9}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 277, 'selector_id': 7, 'selector_address': 289, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 19, 'h': 11, 'x': 16, 'y': 8, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 5, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 294, 'selector_id': 8, 'selector_address': 307, 'allocation': 408, 'block_valid_texels': 9}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 3, 'base': 22, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 226, 'selector_id': 3, 'selector_address': 234, 'allocation': 255, 'block_valid_texels': 4})], 3: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 33, 'selector_id': 0, 'selector_address': 38, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 8, 'h': 6, 'x': 1, 'y': 2, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 2, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 33, 'selector_id': 9, 'selector_address': 47, 'allocation': 102, 'block_valid_texels': 12}), ({'w': 12, 'h': 10, 'x': 8, 'y': 6, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 4, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 169, 'selector_id': 0, 'selector_address': 174, 'allocation': 204, 'block_valid_texels': 12}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 288, 'selector_id': 7, 'selector_address': 300, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 20, 'h': 12, 'x': 16, 'y': 8, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 5, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 305, 'selector_id': 8, 'selector_address': 318, 'allocation': 408, 'block_valid_texels': 12}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 4, 'base': 33, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 237, 'selector_id': 3, 'selector_address': 245, 'allocation': 255, 'block_valid_texels': 4})], 4: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 44, 'selector_id': 0, 'selector_address': 49, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 9, 'h': 7, 'x': 1, 'y': 2, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 3, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 44, 'selector_id': 9, 'selector_address': 58, 'allocation': 153, 'block_valid_texels': 12}), ({'w': 13, 'h': 11, 'x': 8, 'y': 6, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 282, 'selector_id': 0, 'selector_address': 287, 'allocation': 408, 'block_valid_texels': 12}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 299, 'selector_id': 7, 'selector_address': 311, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 21, 'h': 13, 'x': 16, 'y': 8, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 6, 'block_rows': 5, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 316, 'selector_id': 8, 'selector_address': 329, 'allocation': 510, 'block_valid_texels': 12}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 5, 'base': 44, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 248, 'selector_id': 3, 'selector_address': 256, 'allocation': 255, 'block_valid_texels': 4})], 5: [({'w': 1, 'h': 1, 'x': 0, 'y': 0, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 1, 'block_rows': 1, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 55, 'selector_id': 0, 'selector_address': 60, 'allocation': 51, 'block_valid_texels': 1}), ({'w': 10, 'h': 8, 'x': 1, 'y': 2, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 3, 'block_rows': 3, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 55, 'selector_id': 9, 'selector_address': 69, 'allocation': 153, 'block_valid_texels': 12}), ({'w': 14, 'h': 12, 'x': 8, 'y': 6, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 4, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 293, 'selector_id': 0, 'selector_address': 298, 'allocation': 408, 'block_valid_texels': 12}), ({'w': 16, 'h': 8, 'x': 15, 'y': 7, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 4, 'block_rows': 3, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 310, 'selector_id': 7, 'selector_address': 322, 'allocation': 306, 'block_valid_texels': 8}), ({'w': 22, 'h': 14, 'x': 16, 'y': 8, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 6, 'block_rows': 5, 'padded_columns': 6, 'block_size': 17, 'row_pitch': 102, 'block_start': 327, 'selector_id': 8, 'selector_address': 340, 'allocation': 510, 'block_valid_texels': 12}), ({'w': 7, 'h': 13, 'x': 3, 'y': 12, 'b': 6, 'base': 55, 'endpoints': 5}, {'block_columns': 2, 'block_rows': 5, 'padded_columns': 3, 'block_size': 17, 'row_pitch': 51, 'block_start': 259, 'selector_id': 3, 'selector_address': 267, 'allocation': 255, 'block_valid_texels': 4})]}
for i, (p, expected) in enumerate(cases[N]):
    check("layout fixture " + str(i + 1), solve(p), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
layout fixture 1{'allocation': 51, 'block_columns': 1, 'block_rows': 1, 'block_size': 17, 'block_start': 11, 'block_valid_texels': 1, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 16, 'selector_id': 0}{'allocation': 51, 'block_columns': 1, 'block_rows': 1, 'block_size': 17, 'block_start': 11, 'block_valid_texels': 1, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 16, 'selector_id': 0}Passed
layout fixture 2{'allocation': 102, 'block_columns': 2, 'block_rows': 2, 'block_size': 17, 'block_start': 11, 'block_valid_texels': 12, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 25, 'selector_id': 9}{'allocation': 102, 'block_columns': 2, 'block_rows': 2, 'block_size': 17, 'block_start': 11, 'block_valid_texels': 12, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 25, 'selector_id': 9}Passed
layout fixture 3{'allocation': 153, 'block_columns': 3, 'block_rows': 3, 'block_size': 17, 'block_start': 147, 'block_valid_texels': 4, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 160, 'selector_id': 8}{'allocation': 153, 'block_columns': 3, 'block_rows': 3, 'block_size': 17, 'block_start': 147, 'block_valid_texels': 4, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 152, 'selector_id': 0}Failed
layout fixture 4{'allocation': 306, 'block_columns': 4, 'block_rows': 3, 'block_size': 17, 'block_start': 266, 'block_valid_texels': 8, 'padded_columns': 6, 'row_pitch': 102, 'selector_address': 286, 'selector_id': 15}{'allocation': 306, 'block_columns': 4, 'block_rows': 3, 'block_size': 17, 'block_start': 266, 'block_valid_texels': 8, 'padded_columns': 6, 'row_pitch': 102, 'selector_address': 278, 'selector_id': 7}Failed
layout fixture 5{'allocation': 408, 'block_columns': 5, 'block_rows': 4, 'block_size': 17, 'block_start': 283, 'block_valid_texels': 6, 'padded_columns': 6, 'row_pitch': 102, 'selector_address': 288, 'selector_id': 0}{'allocation': 408, 'block_columns': 5, 'block_rows': 4, 'block_size': 17, 'block_start': 283, 'block_valid_texels': 6, 'padded_columns': 6, 'row_pitch': 102, 'selector_address': 296, 'selector_id': 8}Failed
layout fixture 6{'allocation': 255, 'block_columns': 2, 'block_rows': 5, 'block_size': 17, 'block_start': 215, 'block_valid_texels': 4, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 223, 'selector_id': 3}{'allocation': 255, 'block_columns': 2, 'block_rows': 5, 'block_size': 17, 'block_start': 215, 'block_valid_texels': 4, 'padded_columns': 3, 'row_pitch': 51, 'selector_address': 223, 'selector_id': 3}Passed

SHA-256 / 4598f04f4806ed9ccc4739df7ddf9b50f8a98a1bd83dabda681a2a2c4d183f0e

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 6 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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Verification & scope

Stipulated deterministic toy buffer layout; not a graphics API, codec, GPU vendor tiling specification, or hardware-conformance claim. Inputs satisfy the dimensions and bounds stated by the model. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:45:24.987356+00:00.

Case digest / 2be3465fbf67a3db04e568aeac5c48709a7cba4952b64efe214eccff27786c90