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, basestring):
if isinstance(geo_input, unicode):
# 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.GEOJSON 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 __init__(self, geom_input, srs=None):
"Initializes Geometry on either WKT or an OGR pointer as input."
str_instance = isinstance(geom_input, basestring)
# If HEX, unpack input to to a binary buffer.
if str_instance and hex_regex.match(geom_input):
geom_input = buffer(a2b_hex(geom_input.upper()))
str_instance = False
# Constructing the geometry,
if str_instance:
# Checking if unicode
if isinstance(geom_input, unicode):
# Encoding to ASCII, WKT or HEX doesn't need any more.
geom_input = geom_input.encode('ascii')
wkt_m = wkt_regex.match(geom_input)
json_m = json_regex.match(geom_input)
if wkt_m:
if wkt_m.group('srid'):
# If there's EWKT, set the SRS w/value of the SRID.
srs = int(wkt_m.group('srid'))
if wkt_m.group('type').upper() == 'LINEARRING':
# OGR_G_CreateFromWkt doesn't work with LINEARRING WKT.
# See http://trac.osgeo.org/gdal/ticket/1992.
g = capi.create_geom(OGRGeomType(wkt_m.group('type')).num)
capi.import_wkt(g, byref(c_char_p(wkt_m.group('wkt'))))
else:
g = capi.from_wkt(
byref(c_char_p(wkt_m.group('wkt'))), None,
byref(c_void_p()))
elif json_m:
if GEOJSON:
g = capi.from_json(geom_input)
else:
raise NotImplementedError(
'GeoJSON input only supported on GDAL 1.5+.')
else:
# Seeing if the input is a valid short-hand string
# (e.g., 'Point', 'POLYGON').
ogr_t = OGRGeomType(geom_input)
g = capi.create_geom(OGRGeomType(geom_input).num)
elif isinstance(geom_input, buffer):
# WKB was passed in
g = capi.from_wkb(
str(geom_input), None, byref(c_void_p()), len(geom_input))
elif isinstance(geom_input, OGRGeomType):
# OGRGeomType was passed in, an empty geometry will be created.
g = capi.create_geom(geom_input.num)
elif isinstance(geom_input, self.ptr_type):
# OGR pointer (c_void_p) was the input.
g = geom_input
else:
raise OGRException(
'Invalid input type for OGR Geometry construction: %s' %
type(geom_input))
# Now checking the Geometry pointer before finishing initialization
# by setting the pointer for the object.
if not g:
raise OGRException(
'Cannot create OGR Geometry from input: %s' % str(geom_input))
self.ptr = g
# Assigning the SpatialReference object to the geometry, if valid.
if bool(srs): self.srs = srs
# Setting the class depending upon the OGR Geometry Type
self.__class__ = GEO_CLASSES[self.geom_type.num]