Merge branch 'fix-mesh-strip-and-loop' into mesh-strip-split

Author: tomvanmele

src/compas/datastructures/mesh/mesh.py

@@ -35,7 +35,6 @@
 from compas.geometry import vector_average
 
 from compas.utilities import linspace
-from compas.utilities import meshgrid
 
 from compas.utilities import geometric_key
 from compas.utilities import pairwise
@@ -641,16 +640,15 @@ def from_meshgrid(cls, dx, nx, dy=None, ny=None):
         dy = dy or dx
         ny = ny or nx
 
-        U, V = meshgrid(linspace(0, dx, nx + 1), linspace(0, dy, ny + 1), indexing='ij')
-
-        quads = [[
-            [U[i + 0][j + 0], V[i + 0][j + 0], 0.0],
-            [U[i + 0][j + 1], V[i + 0][j + 1], 0.0],
-            [U[i + 1][j + 1], V[i + 1][j + 1], 0.0],
-            [U[i + 1][j + 0], V[i + 1][j + 0], 0.0]
+        vertices = [[x, y, 0.0] for x, y in product(linspace(0, dx, nx + 1), linspace(0, dy, ny + 1))]
+        faces = [[
+            i * (ny + 1) + j,
+            (i + 1) * (ny + 1) + j,
+            (i + 1) * (ny + 1) + j + 1, 
+            i * (ny + 1) + j + 1
         ] for i, j in product(range(nx), range(ny))]
 
-        return cls.from_polygons(quads)
+        return cls.from_vertices_and_faces(vertices, faces)
 
     # --------------------------------------------------------------------------
     # helpers

tests/compas/datastructures/test_halfedge.py

@@ -271,7 +271,7 @@ def test_del_edge_attribute_in_view(mesh, edge_key):
 # Tests - Loops & Strip
 # ==============================================================================
 
-def test_loops_and_strips(sphere):
+def test_loops_and_strips_closed(sphere):
     poles = list(sphere.vertices_where({'vertex_degree': 16}))
 
     for nbr in sphere.vertex_neighbors(poles[0]):
@@ -293,7 +293,6 @@ def test_loops_and_strips(sphere):
             assert len(ring) == 16, ring
             assert ring[0][0] == ring[-1][1]
 
-
 def test_split_strip_closed(box):
     edge = box.edge_sample()[0]
 
@@ -320,3 +319,53 @@ def test_split_strip_open_corner(grid):
 
     assert grid.is_valid()
     assert grid.number_of_faces() == 121
+
+
+def test_loops_and_strips_open(grid):
+    assert grid.number_of_edges() == 220
+
+    edge = 47, 48
+    strip = grid.edge_strip(edge)
+    loop = grid.edge_loop(edge)
+
+    assert edge in strip
+    assert len(strip) == 11
+    assert grid.is_edge_on_boundary(* strip[0])
+    assert grid.is_edge_on_boundary(* strip[-1])
+
+    assert edge in loop
+    assert len(loop) == 10
+    assert grid.is_vertex_on_boundary(loop[0][0])
+    assert grid.is_vertex_on_boundary(loop[-1][1])
+
+
+def test_loops_and_strips_open_corner(grid):
+    assert grid.number_of_edges() == 220
+
+    edge = 0, 1
+    loop = grid.edge_loop(edge)
+    strip = grid.edge_strip(edge)
+
+    assert edge in strip
+    assert len(strip) == 11
+    assert grid.is_edge_on_boundary(* strip[0])
+    assert grid.is_edge_on_boundary(* strip[-1])
+    assert edge == strip[-1]
+
+    assert edge in loop
+    assert len(loop) == 10
+    assert edge == loop[0]
+
+    edge = 1, 0
+    loop = grid.edge_loop(edge)
+    strip = grid.edge_strip(edge)
+
+    assert edge in strip
+    assert len(strip) == 11
+    assert grid.is_edge_on_boundary(* strip[0])
+    assert grid.is_edge_on_boundary(* strip[-1])
+    assert edge == strip[0]
+
+    assert edge in loop
+    assert len(loop) == 10
+    assert edge == loop[-1]