test(codes): compare QR with segno, decode QR dumps and the QR screenshot

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 75 insertions, 0 deletions

diff --git a/tools/gen_qr_tables.py b/tools/gen_qr_tables.py
new file mode 100644
index 0000000..68e6355
--- /dev/null
+++ b/tools/gen_qr_tables.py
@@ -0,0 +1,75 @@
+#!/usr/bin/env python3
+# Author:  cirakg & claude ai
+# Summary: Generate source/codes/QrTables.mc (QR error-correction block structure) from segno's published constants.
+"""QR block structure for versions 1-40 and levels L, M, Q, H (ISO/IEC 18004
+table 9), taken from segno so it isn't typed by hand. Each entry is
+[ec codewords per block, blocks in group 1, data codewords per group-1
+block, blocks in group 2, data codewords per group-2 block].
+
+    gen_qr_tables.py [--out source/codes/QrTables.mc]
+"""
+
+from __future__ import annotations
+
+import argparse
+from pathlib import Path
+from typing import Any, cast
+
+import segno.consts as c
+
+LEVELS = [c.ERROR_LEVEL_L, c.ERROR_LEVEL_M, c.ERROR_LEVEL_Q, c.ERROR_LEVEL_H]
+# segno.consts.ECC: version -> level -> tuple of EC(num_blocks, num_total, num_data); untyped in segno.
+ECC = cast(dict[int, dict[int, tuple[Any, ...]]], c.ECC)
+
+
+def table() -> list[list[int]]:
+    rows = []
+    for version in range(1, 41):
+        for level in LEVELS:
+            groups = ECC[version][level]
+            ec = groups[0].num_total - groups[0].num_data
+            g1 = groups[0]
+            g2 = groups[1] if len(groups) > 1 else None
+            assert all(g.num_total - g.num_data == ec for g in groups)
+            rows.append([ec, g1.num_blocks, g1.num_data, g2.num_blocks if g2 else 0, g2.num_data if g2 else 0])
+    return rows
+
+
+def alignment() -> list[list[int]]:
+    """Alignment pattern centre coordinates per version (ISO/IEC 18004 annex E)."""
+    # segno starts at version 2; version 1 has no alignment pattern.
+    return [[]] + [list(c.ALIGNMENT_POS[v - 2]) for v in range(2, 41)]
+
+
+def render(rows: list[list[int]]) -> str:
+    lines = []
+    for version in range(1, 41):
+        cells = ", ".join(str(n) for level in range(4) for n in rows[(version - 1) * 4 + level])
+        lines.append(f"        {cells}{'' if version == 40 else ','} // version {version}: L, M, Q, H")
+    return (
+        "// Author:  cirakg & claude ai\n"
+        "// Summary: QR error-correction block structure per version and level (generated from segno; do not edit).\n"
+        "//\n"
+        "// Generated by tools/gen_qr_tables.py. For version v (1-40) and level e (0 L, 1 M, 2 Q, 3 H), the five\n"
+        "// numbers at index ((v - 1) * 4 + e) * 5 are: EC codewords per block, group-1 blocks, data codewords\n"
+        "// per group-1 block, group-2 blocks, data codewords per group-2 block (ISO/IEC 18004 table 9).\n\n"
+        "import Toybox.Lang;\n\nmodule QrTables {\n    const BLOCKS = [\n"
+        + "\n".join(lines)
+        + "\n    ];\n\n    // Alignment pattern centres (row and column coordinates) per version, from version 1.\n"
+        + "    const ALIGNMENT = [\n"
+        + ",\n".join(f"        {pos}" for pos in alignment())
+        + "\n    ];\n}\n"
+    )
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
+    parser.add_argument("--out", type=Path, default=Path("source/codes/QrTables.mc"))
+    args = parser.parse_args(argv)
+    args.out.write_text(render(table()), encoding="utf-8")
+    print(f"wrote the QR block table to {args.out}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())