Govern task context and advance execution pointer

tools/web/check-material-desktop.py

@@ -0,0 +1,86 @@
+#!/usr/bin/env python3
+import hashlib
+import json
+import os
+import pathlib
+import sys
+import tempfile
+
+import bpy
+
+
+def rounded(value):
+    return round(float(value), 6)
+
+
+def socket_value(node, name, fallback):
+    socket = node.inputs.get(name)
+    if socket is None:
+        return fallback
+    value = socket.default_value
+    if hasattr(value, "__len__"):
+        return [rounded(item) for item in value]
+    return rounded(value)
+
+
+def material_report():
+    material = bpy.data.materials.get("WebGapMaterial")
+    if material is None or not material.use_nodes:
+        raise RuntimeError("WebGapMaterial node tree is missing")
+    nodes = material.node_tree.nodes
+    principled = nodes.get("Principled BSDF")
+    if principled is None:
+        raise RuntimeError("WebGapMaterial Principled node is missing")
+    return {
+        "id": "material:WebGapMaterial",
+        "name": material.name,
+        "baseColor": socket_value(principled, "Base Color", [0.8, 0.8, 0.8, 1.0]),
+        "roughness": socket_value(principled, "Roughness", 0.4),
+        "metallic": socket_value(principled, "Metallic", 0.0),
+        "emissionColor": socket_value(principled, "Emission Color", [0.0, 0.0, 0.0, 1.0]),
+        "alpha": socket_value(principled, "Alpha", 1.0),
+        "ior": socket_value(principled, "IOR", 1.45),
+        "specularIORLevel": socket_value(principled, "Specular IOR Level", 0.5),
+        "transmissionWeight": socket_value(principled, "Transmission Weight", 0.0),
+        "coatWeight": socket_value(principled, "Coat Weight", 0.0),
+        "coatRoughness": socket_value(principled, "Coat Roughness", 0.03),
+        "emissionStrength": socket_value(principled, "Emission Strength", 1.0),
+        "nodeTypes": sorted(node.bl_idname for node in nodes),
+        "linkCount": len(material.node_tree.links),
+    }
+
+
+def main() -> None:
+    arguments = sys.argv[sys.argv.index("--") + 1 :]
+    if len(arguments) != 2:
+        raise SystemExit("usage: blender -b --python check-material-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 = material_report()
+    descriptor, temporary = tempfile.mkstemp(prefix="m16-material-reopen-", suffix=".blend", dir=fixture.parent)
+    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 = material_report()
+    finally:
+        pathlib.Path(temporary).unlink(missing_ok=True)
+    if before != after:
+        raise RuntimeError(f"material save/reopen drift: {before} != {after}")
+    report = {
+        "schemaVersion": 1,
+        "task": "M16-GAP-00013",
+        "operation": "MATERIAL_DATABLOCK_DESKTOP",
+        "fixture": str(fixture),
+        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
+        "material": 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"material-desktop-ok id={after['id']} nodes={len(after['nodeTypes'])} links={after['linkCount']} saveReopen=exact")
+
+
+if __name__ == "__main__":
+    main()