# -*- coding: utf-8 -*-
"""
===============================================================================
Helper functions (:mod:`sknano.core.geometric_regions.misc`)
===============================================================================
.. currentmodule:: sknano.core.geometric_regions.misc
"""
from __future__ import absolute_import, division, print_function
from __future__ import unicode_literals
import numpy as np
__all__ = ['generate_bounding_box']
from ._3D_regions import Cuboid
[docs]def generate_bounding_box(from_region=None, from_lattice=None, from_array=None,
verbose=False):
"""Return a :class:`~sknano.core.geometric_regions.Cuboid` \
representing an axis-aligned bounding box.
Parameters
----------
from_region : :class:`~sknano.core.geometric_regions.Geometric3DRegion`
from_lattice : :class:`~sknano.core.crystallography.Crystal3DLattice`
from_array : :class:`~numpy:numpy.ndarray`
verbose : :class:`~python:bool`
Returns
-------
bounding_box : :class:`~sknano.core.geometric_regions.Cuboid`
"""
if all([obj is None for obj in (from_region, from_lattice, from_array)]):
return None
bounding_box = Cuboid()
if from_region is not None:
region = from_region
bounding_box.pmin = region.pmin
bounding_box.pmax = region.pmax
elif from_lattice is not None:
lattice = from_lattice
# if np.allclose(np.radians(lattice.angles), np.pi / 2 * np.ones(3)):
# lattice_region =
# bounding_box.pmin = lattice_region.pmin
# bounding_box.pmax = lattice_region.pmax
# else:
a, b, c = lattice.lengths
cos_alpha, cos_beta, cos_gamma = np.cos(np.radians(lattice.angles))
lx = a
xy = b * cos_gamma
xz = c * cos_beta
ly = np.sqrt(b ** 2 - xy ** 2)
yz = (b * c * cos_alpha - xy * xz) / ly
lz = np.sqrt(c ** 2 - xz ** 2 - yz ** 2)
lattice_region = lattice.region
xlo, ylo, zlo = lattice_region.o
if verbose:
print('xy={}, xz={}, yz={}'.format(xy, xz, yz))
print('lx={}, ly={}, lz={}'.format(lx, ly, lz))
print('xlo={}, ylo={}, zlo={}'.format(xlo, ylo, zlo))
print('lattice.region.centroid: {}'.format(
lattice_region.centroid))
xlo_bound = xlo + min(0.0, xy, xz, xy + xz)
xhi_bound = xlo + lx + max(0.0, xy, xz, xy + xz)
ylo_bound = ylo + min(0.0, yz)
yhi_bound = ylo + ly + max(0.0, yz)
zlo_bound = zlo
zhi_bound = zlo + lz
bounding_box.pmin = [xlo_bound, ylo_bound, zlo_bound]
bounding_box.pmax = [xhi_bound, yhi_bound, zhi_bound]
if verbose:
print('bounding_box: {}'.format(bounding_box))
print('orientation_matrix: {}'.format(lattice.orientation_matrix))
assert bounding_box.pmin <= bounding_box.pmax
else:
array = np.asarray(from_array)
for i, dim in enumerate(('x', 'y', 'z')):
setattr(bounding_box, dim + 'min', array[:, i].min())
setattr(bounding_box, dim + 'max', array[:, i].max())
return bounding_box
