BMesh: remove redundant mesh-backups from EDBM_op_* API

Using BMesh operators through the edit-mesh API created a full copy
of the mesh so it was possible to restore the mesh in case
one of the operators raised an error.

Remove support for automatic backup/restore from the EDBM_op_* API's
as it adds significant overhead and was rarely used.

Operators that need this can use the BMBackup API to backup & restore
the mesh in case of failure.

Add warning levels to BMO_error_raise so operators can report problems
without it being interpreted as a request to cancel the operation.

For high-poly meshes creating and freeing a full copy is an expensive
operation, removing this gives a speedup of ~1.77x for most operators
except for "connect_verts" / "connect_vert_pair"
which still uses this functionality.

1 files changed, 3 insertions, 3 deletions

diff --git a/source/blender/bmesh/operators/bmo_bridge.c b/source/blender/bmesh/operators/bmo_bridge.c
index 005b8a2f5e8..fb913d4f19f 100644
--- a/source/blender/bmesh/operators/bmo_bridge.c
+++ b/source/blender/bmesh/operators/bmo_bridge.c
@@ -576,12 +576,12 @@ void bmo_bridge_loops_exec(BMesh *bm, BMOperator *op)
   BM_mesh_edgeloops_calc_center(bm, &eloops);
 
   if (count < 2) {
-    BMO_error_raise(bm, op, "Select at least two edge loops");
+    BMO_error_raise(bm, op, BMO_ERROR_CANCEL, "Select at least two edge loops");
     goto cleanup;
   }
 
   if (use_pairs && (count % 2)) {
-    BMO_error_raise(bm, op, "Select an even number of loops to bridge pairs");
+    BMO_error_raise(bm, op, BMO_ERROR_CANCEL, "Select an even number of loops to bridge pairs");
     goto cleanup;
   }
 
@@ -595,7 +595,7 @@ void bmo_bridge_loops_exec(BMesh *bm, BMOperator *op)
       }
     }
     if (!match) {
-      BMO_error_raise(bm, op, "Selected loops must have equal edge counts");
+      BMO_error_raise(bm, op, BMO_ERROR_CANCEL, "Selected loops must have equal edge counts");
       goto cleanup;
     }
   }