def polyedge_from_to_via_vertices(mesh, from_vkey, to_vkey, via_vkeys): # return shortest polyedge from_vkey to_vkey via_vkeys adjacency = adjacency_from_to_via_vertices(mesh, from_vkey, to_vkey, via_vkeys) return next(breadth_first_paths(adjacency, from_vkey, to_vkey))
def strip_polyedge_update(mesh, polyedge, vertex_modifications):
"""Update a polyedge in mesh that has been modified.
Parameters
----------
mesh : QuadMesh
A quad mesh.
polyedge : list
A polyedge as a list of (old) vertex keys.
vertex_modifications : dict
A dictionary showing the vertex modifications, old vertex keys pointing to the new vertex keys.
Returns
-------
shortest_polyedge: list
The updated polyedge as a list of vertex keys.
"""
closed = polyedge[0] == polyedge[-1]
if closed:
polyedge = polyedge[:-1]
# update polyedge with candidate vertices
polyedge_modifications = {
vkey: (vertex_modifications[vkey]
if vkey in vertex_modifications else [vkey])
for vkey in polyedge
}
# list all candidate vertices to form new polyedge
candidate_vertices = tuple(
set([
vkey for vkeys in polyedge_modifications.values() for vkey in vkeys
]))
# adjacency restricted to candidate vertices
adjacency = {
vkey: [
nbr for nbr in mesh.vertex_neighbors(vkey)
if nbr in candidate_vertices
]
for vkey in mesh.vertices() if vkey in candidate_vertices
}
# for each combination of boundary vertex extremities, get the shortest
# valid path through the modified vertices of the polyedges
shortest_polyedge = None
# start vertices on boundary
for vkey_start in polyedge_modifications[polyedge[0]]:
if mesh.is_vertex_on_boundary(vkey_start):
# end vertices on boundary
for vkey_end in polyedge_modifications[polyedge[-1]]:
if mesh.is_vertex_on_boundary(vkey_end):
# iterate through all paths between start and end vertices
# starting by the shortest
for candidate_polyedge in breadth_first_paths(
adjacency, vkey_start, vkey_end):
is_valid = True
# if was initailly closed, make sure that temporary end
# is adjacent to start
if closed:
if candidate_polyedge[
0] not in mesh.vertex_neighbors(
candidate_polyedge[-1]):
continue
# check that vertices in path come from the modified
# vertices of the polyedge in the same order
i = 0
for vkey in candidate_polyedge:
if vkey in polyedge_modifications[polyedge[i]]:
continue
elif vkey in polyedge_modifications[polyedge[i +
1]]:
i += 1
else:
is_valid = False
break
# update if shorter
if is_valid:
if shortest_polyedge is None or len(
shortest_polyedge) > len(
candidate_polyedge):
shortest_polyedge = candidate_polyedge
break
if closed:
shortest_polyedge.append(shortest_polyedge[0])
return shortest_polyedge