from ctypes import c_uint
from django.contrib.gis import gdal
from django.contrib.gis.geos import prototypes as capi
from django.contrib.gis.geos.error import GEOSException
from django.contrib.gis.geos.geometry import GEOSGeometry
[文档]
class Point(GEOSGeometry):
_minlength = 2
_maxlength = 3
has_cs = True
def __init__(self, x=None, y=None, z=None, srid=None):
"""
The Point object may be initialized with either a tuple, or individual
parameters.
For example:
>>> p = Point((5, 23)) # 2D point, passed in as a tuple
>>> p = Point(5, 23, 8) # 3D point, passed in with individual parameters
"""
if x is None:
coords = []
elif isinstance(x, (tuple, list)):
# Here a tuple or list was passed in under the `x` parameter.
coords = x
elif isinstance(x, (float, int)) and isinstance(y, (float, int)):
# Here X, Y, and (optionally) Z were passed in individually, as parameters.
if isinstance(z, (float, int)):
coords = [x, y, z]
else:
coords = [x, y]
else:
raise TypeError("Invalid parameters given for Point initialization.")
point = self._create_point(len(coords), coords)
# Initializing using the address returned from the GEOS
# createPoint factory.
super().__init__(point, srid=srid)
def _to_pickle_wkb(self):
return None if self.empty else super()._to_pickle_wkb()
def _from_pickle_wkb(self, wkb):
return self._create_empty() if wkb is None else super()._from_pickle_wkb(wkb)
def _ogr_ptr(self):
return (
gdal.geometries.Point._create_empty() if self.empty else super()._ogr_ptr()
)
@classmethod
def _create_empty(cls):
return cls._create_point(None, None)
@classmethod
def _create_point(cls, ndim, coords):
"""
Create a coordinate sequence, set X, Y, [Z], and create point
"""
if not ndim:
return capi.create_point(None)
if ndim < 2 or ndim > 3:
raise TypeError("Invalid point dimension: %s" % ndim)
cs = capi.create_cs(c_uint(1), c_uint(ndim))
i = iter(coords)
capi.cs_setx(cs, 0, next(i))
capi.cs_sety(cs, 0, next(i))
if ndim == 3:
capi.cs_setz(cs, 0, next(i))
return capi.create_point(cs)
def _set_list(self, length, items):
ptr = self._create_point(length, items)
if ptr:
srid = self.srid
capi.destroy_geom(self.ptr)
self._ptr = ptr
if srid is not None:
self.srid = srid
self._post_init()
else:
# can this happen?
raise GEOSException("Geometry resulting from slice deletion was invalid.")
def _set_single(self, index, value):
self._cs.setOrdinate(index, 0, value)
def __iter__(self):
"Iterate over coordinates of this Point."
for i in range(len(self)):
yield self[i]
def __len__(self):
"Return the number of dimensions for this Point (either 0, 2 or 3)."
if self.empty:
return 0
if self.hasz:
return 3
else:
return 2
def _get_single_external(self, index):
if index == 0:
return self.x
elif index == 1:
return self.y
elif index == 2:
return self.z
_get_single_internal = _get_single_external
@property
def x(self):
"Return the X component of the Point."
return self._cs.getOrdinate(0, 0)
@x.setter
def x(self, value):
"Set the X component of the Point."
self._cs.setOrdinate(0, 0, value)
@property
def y(self):
"Return the Y component of the Point."
return self._cs.getOrdinate(1, 0)
@y.setter
def y(self, value):
"Set the Y component of the Point."
self._cs.setOrdinate(1, 0, value)
@property
def z(self):
"Return the Z component of the Point."
return self._cs.getOrdinate(2, 0) if self.hasz else None
@z.setter
def z(self, value):
"Set the Z component of the Point."
if not self.hasz:
raise GEOSException("Cannot set Z on 2D Point.")
self._cs.setOrdinate(2, 0, value)
# ### Tuple setting and retrieval routines. ###
@property
def tuple(self):
"Return a tuple of the point."
return self._cs.tuple
@tuple.setter
def tuple(self, tup):
"Set the coordinates of the point with the given tuple."
self._cs[0] = tup
# The tuple and coords properties
coords = tuple
12月 18, 2023