164 lines
5.4 KiB
Python
164 lines
5.4 KiB
Python
"""
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This module houses the GEOSCoordSeq object, which is used internally
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by GEOSGeometry to house the actual coordinates of the Point,
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LineString, and LinearRing geometries.
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"""
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from ctypes import c_double, c_uint, byref
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from django.contrib.gis.geos.base import GEOSBase, numpy
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from django.contrib.gis.geos.error import GEOSException, GEOSIndexError
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from django.contrib.gis.geos.libgeos import CS_PTR
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from django.contrib.gis.geos import prototypes as capi
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from django.utils.six.moves import xrange
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class GEOSCoordSeq(GEOSBase):
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"The internal representation of a list of coordinates inside a Geometry."
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ptr_type = CS_PTR
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#### Python 'magic' routines ####
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def __init__(self, ptr, z=False):
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"Initializes from a GEOS pointer."
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if not isinstance(ptr, CS_PTR):
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raise TypeError('Coordinate sequence should initialize with a CS_PTR.')
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self._ptr = ptr
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self._z = z
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def __iter__(self):
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"Iterates over each point in the coordinate sequence."
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for i in xrange(self.size):
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yield self[i]
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def __len__(self):
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"Returns the number of points in the coordinate sequence."
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return int(self.size)
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def __str__(self):
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"Returns the string representation of the coordinate sequence."
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return str(self.tuple)
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def __getitem__(self, index):
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"Returns the coordinate sequence value at the given index."
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coords = [self.getX(index), self.getY(index)]
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if self.dims == 3 and self._z:
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coords.append(self.getZ(index))
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return tuple(coords)
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def __setitem__(self, index, value):
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"Sets the coordinate sequence value at the given index."
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# Checking the input value
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if isinstance(value, (list, tuple)):
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pass
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elif numpy and isinstance(value, numpy.ndarray):
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pass
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else:
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raise TypeError('Must set coordinate with a sequence (list, tuple, or numpy array).')
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# Checking the dims of the input
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if self.dims == 3 and self._z:
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n_args = 3
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set_3d = True
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else:
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n_args = 2
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set_3d = False
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if len(value) != n_args:
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raise TypeError('Dimension of value does not match.')
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# Setting the X, Y, Z
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self.setX(index, value[0])
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self.setY(index, value[1])
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if set_3d:
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self.setZ(index, value[2])
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#### Internal Routines ####
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def _checkindex(self, index):
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"Checks the given index."
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sz = self.size
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if (sz < 1) or (index < 0) or (index >= sz):
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raise GEOSIndexError('invalid GEOS Geometry index: %s' % str(index))
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def _checkdim(self, dim):
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"Checks the given dimension."
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if dim < 0 or dim > 2:
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raise GEOSException('invalid ordinate dimension "%d"' % dim)
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#### Ordinate getting and setting routines ####
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def getOrdinate(self, dimension, index):
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"Returns the value for the given dimension and index."
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self._checkindex(index)
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self._checkdim(dimension)
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return capi.cs_getordinate(self.ptr, index, dimension, byref(c_double()))
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def setOrdinate(self, dimension, index, value):
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"Sets the value for the given dimension and index."
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self._checkindex(index)
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self._checkdim(dimension)
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capi.cs_setordinate(self.ptr, index, dimension, value)
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def getX(self, index):
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"Get the X value at the index."
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return self.getOrdinate(0, index)
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def setX(self, index, value):
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"Set X with the value at the given index."
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self.setOrdinate(0, index, value)
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def getY(self, index):
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"Get the Y value at the given index."
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return self.getOrdinate(1, index)
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def setY(self, index, value):
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"Set Y with the value at the given index."
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self.setOrdinate(1, index, value)
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def getZ(self, index):
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"Get Z with the value at the given index."
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return self.getOrdinate(2, index)
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def setZ(self, index, value):
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"Set Z with the value at the given index."
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self.setOrdinate(2, index, value)
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### Dimensions ###
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@property
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def size(self):
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"Returns the size of this coordinate sequence."
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return capi.cs_getsize(self.ptr, byref(c_uint()))
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@property
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def dims(self):
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"Returns the dimensions of this coordinate sequence."
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return capi.cs_getdims(self.ptr, byref(c_uint()))
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@property
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def hasz(self):
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"""
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Returns whether this coordinate sequence is 3D. This property value is
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inherited from the parent Geometry.
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"""
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return self._z
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### Other Methods ###
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def clone(self):
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"Clones this coordinate sequence."
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return GEOSCoordSeq(capi.cs_clone(self.ptr), self.hasz)
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@property
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def kml(self):
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"Returns the KML representation for the coordinates."
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# Getting the substitution string depending on whether the coordinates have
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# a Z dimension.
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if self.hasz:
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substr = '%s,%s,%s '
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else:
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substr = '%s,%s,0 '
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return '<coordinates>%s</coordinates>' % \
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''.join(substr % self[i] for i in xrange(len(self))).strip()
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@property
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def tuple(self):
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"Returns a tuple version of this coordinate sequence."
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n = self.size
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if n == 1:
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return self[0]
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else:
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return tuple(self[i] for i in xrange(n))
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