def __init__(self, geo_input, srid=None):
"""
The base constructor for GEOS geometry objects, and may take the
following inputs:
* strings:
- WKT
- HEXEWKB (a PostGIS-specific canonical form)
- GeoJSON (requires GDAL)
* buffer:
- WKB
The `srid` keyword is used to specify the Source Reference Identifier
(SRID) number for this Geometry. If not set, the SRID will be None.
"""
if isinstance(geo_input, six.string_types):
if isinstance(geo_input, six.text_type):
# Encoding to ASCII, WKT or HEXEWKB doesn't need any more.
geo_input = geo_input.encode('ascii')
wkt_m = wkt_regex.match(geo_input)
if wkt_m:
# Handling WKT input.
if wkt_m.group('srid'): srid = int(wkt_m.group('srid'))
g = wkt_r().read(wkt_m.group('wkt'))
elif hex_regex.match(geo_input):
# Handling HEXEWKB input.
g = wkb_r().read(geo_input)
elif gdal.HAS_GDAL and json_regex.match(geo_input):
# Handling GeoJSON input.
g = wkb_r().read(gdal.OGRGeometry(geo_input).wkb)
else:
raise ValueError('String or unicode input unrecognized as WKT EWKT, and HEXEWKB.')
elif isinstance(geo_input, GEOM_PTR):
# When the input is a pointer to a geomtry (GEOM_PTR).
g = geo_input
elif isinstance(geo_input, buffer):
# When the input is a buffer (WKB).
g = wkb_r().read(geo_input)
elif isinstance(geo_input, GEOSGeometry):
g = capi.geom_clone(geo_input.ptr)
else:
# Invalid geometry type.
raise TypeError('Improper geometry input type: %s' % str(type(geo_input)))
if bool(g):
# Setting the pointer object with a valid pointer.
self.ptr = g
else:
raise GEOSException('Could not initialize GEOS Geometry with given input.')
# Post-initialization setup.
self._post_init(srid)
def __setstate__(self, state):
# Instantiating from the tuple state that was pickled.
wkb, srid = state
ptr = wkb_r().read(buffer(wkb))
if not ptr: raise GEOSException('Invalid Geometry loaded from pickled state.')
self.ptr = ptr
self._post_init(srid)
def transform(self, ct, clone=False):
"""
Requires GDAL. Transforms the geometry according to the given
transformation object, which may be an integer SRID, and WKT or
PROJ.4 string. By default, the geometry is transformed in-place and
nothing is returned. However if the `clone` keyword is set, then this
geometry will not be modified and a transformed clone will be returned
instead.
"""
srid = self.srid
if ct == srid:
# short-circuit where source & dest SRIDs match
if clone:
return self.clone()
else:
return
if (srid is None) or (srid < 0):
raise GEOSException("Calling transform() with no SRID set is not supported")
if not gdal.HAS_GDAL:
raise GEOSException("GDAL library is not available to transform() geometry.")
# Creating an OGR Geometry, which is then transformed.
g = gdal.OGRGeometry(self.wkb, srid)
g.transform(ct)
# Getting a new GEOS pointer
ptr = wkb_r().read(g.wkb)
if clone:
# User wants a cloned transformed geometry returned.
return GEOSGeometry(ptr, srid=g.srid)
if ptr:
# Reassigning pointer, and performing post-initialization setup
# again due to the reassignment.
capi.destroy_geom(self.ptr)
self.ptr = ptr
self._post_init(g.srid)
else:
raise GEOSException('Transformed WKB was invalid.')
