Govern task context and advance execution pointer

tools/web/check-lattice-desktop.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+import hashlib
+import json
+import os
+import pathlib
+import sys
+import tempfile
+
+import bpy
+
+
+def rounded(values):
+    return [round(float(value), 6) for value in values]
+
+
+def lattice_report():
+    lattice = bpy.data.lattices.get("WebGapLattice")
+    if lattice is None:
+        raise RuntimeError("WebGapLattice is missing")
+    return {
+        "id": "lattice:WebGapLattice",
+        "name": lattice.name,
+        "dimensions": [lattice.points_u, lattice.points_v, lattice.points_w],
+        "pointCount": len(lattice.points),
+        "interpolation": [
+            lattice.interpolation_type_u,
+            lattice.interpolation_type_v,
+            lattice.interpolation_type_w,
+        ],
+        "useOutside": bool(lattice.use_outside),
+        "activePoint": -1,
+        "vertexGroup": lattice.vertex_group,
+        "points": [
+            {
+                "coDeform": rounded(point.co_deform),
+                "weight": round(float(point.weight_softbody), 6),
+                "selected": bool(point.select),
+            }
+            for point in lattice.points
+        ],
+    }
+
+
+def main() -> None:
+    arguments = sys.argv[sys.argv.index("--") + 1 :]
+    if len(arguments) != 2:
+        raise SystemExit("usage: blender -b --python check-lattice-desktop.py -- FIXTURE REPORT")
+    fixture, output = (pathlib.Path(value).resolve() for value in arguments)
+    bpy.ops.wm.open_mainfile(filepath=str(fixture), load_ui=False)
+    before = lattice_report()
+    descriptor, temporary = tempfile.mkstemp(prefix="m16-lattice-reopen-", suffix=".blend")
+    os.close(descriptor)
+    try:
+        bpy.ops.wm.save_as_mainfile(filepath=temporary, check_existing=False, compress=True)
+        bpy.ops.wm.open_mainfile(filepath=temporary, load_ui=False)
+        after = lattice_report()
+    finally:
+        pathlib.Path(temporary).unlink(missing_ok=True)
+    if before != after:
+        raise RuntimeError(f"lattice save/reopen drift: {before} != {after}")
+    report = {
+        "schemaVersion": 1,
+        "task": "M16-GAP-00010",
+        "operation": "LATTICE_DATABLOCK_DESKTOP",
+        "fixture": str(fixture),
+        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
+        "lattice": after,
+        "saveReopen": "EXACT",
+        "blenderVersion": bpy.app.version_string,
+    }
+    output.parent.mkdir(parents=True, exist_ok=True)
+    output.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")
+    print(f"lattice-desktop-ok points={after['pointCount']} saveReopen=exact")
+
+
+if __name__ == "__main__":
+    main()