def get_triangulation(self, normal_vector=None):
# Figure out how to triangulate the interior to know
# how to send the points as to the vertex shader.
# First triangles come directly from the points
if normal_vector is None:
normal_vector = self.get_unit_normal()
if not self.needs_new_triangulation:
return self.triangulation
points = self.get_points()
if len(points) <= 1:
self.triangulation = np.zeros(0, dtype="i4")
self.needs_new_triangulation = False
return self.triangulation
if not np.isclose(normal_vector, OUT).all():
# Rotate points such that unit normal vector is OUT
points = np.dot(points, z_to_vector(normal_vector))
indices = np.arange(len(points), dtype=int)
b0s = points[0::3]
b1s = points[1::3]
b2s = points[2::3]
v01s = b1s - b0s
v12s = b2s - b1s
crosses = cross2d(v01s, v12s)
convexities = np.sign(crosses)
atol = self.tolerance_for_point_equality
end_of_loop = np.zeros(len(b0s), dtype=bool)
end_of_loop[:-1] = (np.abs(b2s[:-1] - b0s[1:]) > atol).any(1)
end_of_loop[-1] = True
concave_parts = convexities < 0
# These are the vertices to which we'll apply a polygon triangulation
inner_vert_indices = np.hstack(
[
indices[0::3],
indices[1::3][concave_parts],
indices[2::3][end_of_loop],
]
)
inner_vert_indices.sort()
rings = np.arange(1, len(inner_vert_indices) + 1)[inner_vert_indices % 3 == 2]
# Triangulate
inner_verts = points[inner_vert_indices]
inner_tri_indices = inner_vert_indices[
earclip_triangulation(inner_verts, rings)
]
tri_indices = np.hstack([indices, inner_tri_indices])
self.triangulation = tri_indices
self.needs_new_triangulation = False
return tri_indices
def get_triangulation(self, orientation=None):
# Figure out how to triangulate the interior to know
# how to send the points as to the vertex shader.
# First triangles come directly from the points
if orientation is None:
orientation = self.get_orientation()
if self.triangulation_locked:
return self.saved_triangulation
if len(self.points) <= 1:
return []
points = self.points
indices = np.arange(len(points), dtype=int)
b0s = points[0::3]
b1s = points[1::3]
b2s = points[2::3]
v01s = b1s - b0s
v12s = b2s - b1s
# TODO, account for 3d
crosses = cross2d(v01s, v12s)
convexities = orientation * np.sign(crosses)
atol = self.tolerance_for_point_equality
end_of_loop = np.zeros(len(b0s), dtype=bool)
end_of_loop[:-1] = (np.abs(b2s[:-1] - b0s[1:]) > atol).any(1)
end_of_loop[-1] = True
concave_parts = convexities < 0
# These are the vertices to which we'll apply a polygon triangulation
inner_vert_indices = np.hstack([
indices[0::3],
indices[1::3][concave_parts],
indices[2::3][end_of_loop],
])
inner_vert_indices.sort()
rings = np.arange(1,
len(inner_vert_indices) + 1)[inner_vert_indices %
3 == 2]
# Triangulate
inner_verts = points[inner_vert_indices]
inner_tri_indices = inner_vert_indices[earclip_triangulation(
inner_verts, rings)]
tri_indices = np.hstack([indices, inner_tri_indices])
return tri_indices
