forked from 170010011/fr
80 lines
2.0 KiB
Python
80 lines
2.0 KiB
Python
|
"""Multi-part collections of geometries
|
||
|
|
"""
|
||
|
|
|
||
|
|
from ctypes import c_void_p
|
||
|
|
|
||
|
|
from shapely.geos import lgeos
|
||
|
|
from shapely.geometry.base import BaseGeometry
|
||
|
|
from shapely.geometry.base import BaseMultipartGeometry
|
||
|
|
from shapely.geometry.base import HeterogeneousGeometrySequence
|
||
|
|
from shapely.geometry.base import geos_geom_from_py
|
||
|
|
|
||
|
|
|
||
|
|
class GeometryCollection(BaseMultipartGeometry):
|
||
|
|
|
||
|
|
"""A heterogenous collection of geometries
|
||
|
|
|
||
|
|
Attributes
|
||
|
|
----------
|
||
|
|
geoms : sequence
|
||
|
|
A sequence of Shapely geometry instances
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self, geoms=None):
|
||
|
|
"""
|
||
|
|
Parameters
|
||
|
|
----------
|
||
|
|
geoms : list
|
||
|
|
A list of shapely geometry instances, which may be heterogenous.
|
||
|
|
|
||
|
|
Example
|
||
|
|
-------
|
||
|
|
Create a GeometryCollection with a Point and a LineString
|
||
|
|
|
||
|
|
>>> p = Point(51, -1)
|
||
|
|
>>> l = LineString([(52, -1), (49, 2)])
|
||
|
|
>>> gc = GeometryCollection([p, l])
|
||
|
|
"""
|
||
|
|
BaseMultipartGeometry.__init__(self)
|
||
|
|
if not geoms:
|
||
|
|
pass
|
||
|
|
else:
|
||
|
|
self._geom, self._ndim = geos_geometrycollection_from_py(geoms)
|
||
|
|
|
||
|
|
@property
|
||
|
|
def __geo_interface__(self):
|
||
|
|
geometries = []
|
||
|
|
for geom in self.geoms:
|
||
|
|
geometries.append(geom.__geo_interface__)
|
||
|
|
return dict(type='GeometryCollection', geometries=geometries)
|
||
|
|
|
||
|
|
@property
|
||
|
|
def geoms(self):
|
||
|
|
if self.is_empty:
|
||
|
|
return []
|
||
|
|
return HeterogeneousGeometrySequence(self)
|
||
|
|
|
||
|
|
def geos_geometrycollection_from_py(ob):
|
||
|
|
"""Creates a GEOS GeometryCollection from a list of geometries"""
|
||
|
|
L = len(ob)
|
||
|
|
N = 2
|
||
|
|
subs = (c_void_p * L)()
|
||
|
|
for l in range(L):
|
||
|
|
assert(isinstance(ob[l], BaseGeometry))
|
||
|
|
if ob[l].has_z:
|
||
|
|
N = 3
|
||
|
|
geom, n = geos_geom_from_py(ob[l])
|
||
|
|
subs[l] = geom
|
||
|
|
|
||
|
|
return (lgeos.GEOSGeom_createCollection(7, subs, L), N)
|
||
|
|
|
||
|
|
# Test runner
|
||
|
|
def _test():
|
||
|
|
import doctest
|
||
|
|
doctest.testmod()
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
_test()
|
||
|
|
|