Relabel entities and groups.

programming/mesh/gmsh/convert_to_msh.py

@@ -4,41 +4,91 @@
 import gmsh
 
 
-def print_physical_groups() -> dict:
-    print()
-    entity_to_group = dict()
+def just_print_entities(prefix=''):
+    entities = gmsh.model.get_entities()
+    for entity in entities:
+        dim, tag = entity
+        name = gmsh.model.get_entity_name(dim, tag)
+        print(f'{prefix} {entity} "{name}"')
+
+
+def just_print_groups(prefix=''):
     groups = gmsh.model.get_physical_groups()
     for group in groups:
         dim, tag = group
         name = gmsh.model.get_physical_name(dim, tag)
-        print(f'{dim}d Physical Group {group} "{name}"')
+        print(f'{prefix} {group} "{name}"')
+
+
+def map_entity_to_group_name() -> dict:
+    prefix = '[map_entity_to_group_name]'
+    entity_to_group_name = dict()
+    groups = gmsh.model.get_physical_groups()
+    for group in groups:
+        dim, tag = group
+        name = gmsh.model.get_physical_name(dim, tag)
+        print(f'{prefix} Group {group} "{name}"')
         tags = gmsh.model.get_entities_for_physical_group(dim, tag)
         for tag in tags:
             entity = (dim, int(tag))
-            entity_to_group[entity] = group
+            entity_to_group_name[entity] = name
             name = gmsh.model.get_entity_name(dim, tag)
-            print(f'  {dim}d Elementary Entity {entity} "{name}"')
-    return entity_to_group
+            print(f'{prefix} -> Entity {entity} "{name}"')
+    print(f'\n{prefix} entity_to_group_name = {entity_to_group_name}')
+    return entity_to_group_name
 
 
-def print_elementary_entities(entity_to_group: dict):
-    print()
-    entities = gmsh.model.get_entities()
-    for entity in entities:
-        dim, tag = entity
-        name = gmsh.model.get_entity_name(dim, tag)
-        # group = gmsh.model.get_physical_groups_for_entity(dim, tag)
-        print(f'{dim}d Elementary Entity {entity} "{name}"')
-        if entity in entity_to_group:
-            group = entity_to_group[entity]
-            dim, tag = group
-            name = gmsh.model.get_physical_name(dim, tag)
-            print(f'  {dim}d Physical Group {group} "{name}" found')
+def update_entities() -> dict:
+    """Re-label entities from 1, 2d entities first, then 3d entities.
+    """
+    prefix = '[update_entities]'
+    print(f'\nat the beginning of {prefix}')
+    just_print_entities(prefix)
+    new_entity_to_old_entity = dict()
+    new_tag = 1
+    for d in (2, 3):
+        old_entities = gmsh.model.get_entities(d)
+        for old_entity in old_entities:
+            dim, old_tag = old_entity
+            assert dim == d
+            name = gmsh.model.get_entity_name(dim, old_tag)
+            if old_tag != new_tag:
+                gmsh.model.set_tag(dim, old_tag, new_tag)
+                gmsh.model.set_entity_name(dim, new_tag, name)
+            new_entity_to_old_entity[(dim, new_tag)] = old_entity
+            new_tag += 1
+    print(f'\n{prefix} new_entity_to_old_entity = {new_entity_to_old_entity}')
+    print(f'\nat the end of {prefix}')
+    just_print_entities(prefix)
+    return new_entity_to_old_entity
+
+
+def update_groups(old_entity_to_group_name: dict, new_entity_to_old_entity: dict):
+    prefix = '[update_groups]'
+    print(f'\n{prefix} old_entity_to_group_name = {old_entity_to_group_name}')
+    print(f'\n{prefix} new_entity_to_old_entity = {new_entity_to_old_entity}')
+    print(f'\nat the beginning of {prefix}')
+    just_print_groups(prefix)
+    gmsh.model.remove_physical_groups()
+    names = old_entity_to_group_name.values()
+    for name in names:
+        gmsh.model.remove_physical_name(name)
+    print(f'\nafter removing all groups')
+    just_print_groups(prefix)
+    print(f'\nadding new groups')
+    for new_entity, old_entity in new_entity_to_old_entity.items():
+        dim, new_tag = new_entity
+        if old_entity in old_entity_to_group_name:
+            name = old_entity_to_group_name[old_entity]
         else:
-            tag = gmsh.model.add_physical_group(dim, [tag], tag, str(entity))
-            name = gmsh.model.get_physical_name(dim, tag)
-            group = (dim, tag)
-            print(f'  {dim}d Physical Group {group} "{name}" created')
+            name = gmsh.model.get_entity_name(dim, new_tag)
+        print(f'{prefix} add_physical_group({dim}, {[new_tag]}, {new_tag}, {name})')
+        group_tag = gmsh.model.add_physical_group(dim, [new_tag], new_tag, name)
+        assert new_tag == group_tag, (new_tag, group_tag)
+        group_name = gmsh.model.get_physical_name(dim, group_tag)
+        assert name == group_name, (old_entity, new_entity, (dim, new_tag), name, group_name)
+    print(f'\nat the end of {prefix}')
+    just_print_groups(prefix)
 
 
 if __name__ == "__main__":
@@ -59,14 +109,26 @@ def print_elementary_entities(entity_to_group: dict):
     input = f'{args.folder}/{args.mesh}'
     gmsh.merge(input)
 
-    entity_to_group = print_physical_groups()
-    print_elementary_entities(entity_to_group)
-    entity_to_group = print_physical_groups()
+    # In Gmsh, index start at 1 with empty name to account for unclassified elements.
+    # See `GModel::readCGNS` in `src/geo/GModelIO_CGNS.cpp` for details.
+    print()
+    just_print_entities('[old entities]')
+    print()
+    just_print_groups('[old groups]')
+
+    old_entity_to_group_name = map_entity_to_group_name()
+    new_entity_to_old_entity = update_entities()
+    update_groups(old_entity_to_group_name, new_entity_to_old_entity)
+
+    print()
+    just_print_entities('[new entities]')
+    print()
+    just_print_groups('[new groups]')
 
+    # gmsh.option.set_number('Mesh.SaveAll', 1)
     dot_pos = input.rfind('.')
     output = f'{input[:dot_pos]}.msh'
-
-    print(output)
+    print(f'\nwriting to {output} ...')
     gmsh.write(output)
 
     gmsh.finalize()