def translate(self, x, y, z=0.0, **kwargs):
"""
Translates the geometry to a new location using the given numeric
parameters as offsets.
"""
if connections[self.db].ops.spatialite:
if z != 0.0:
raise NotImplementedError(
'SpatiaLite does not support 3D translation.')
s = {
'procedure_fmt': '%(geo_col)s,%(x)s,%(y)s',
'procedure_args': {
'x': x,
'y': y
},
'select_field': GeomField(),
}
else:
s = {
'procedure_fmt': '%(geo_col)s,%(x)s,%(y)s,%(z)s',
'procedure_args': {
'x': x,
'y': y,
'z': z
},
'select_field': GeomField(),
}
return self._spatial_attribute('translate', s, **kwargs)
def scale(self, x, y, z=0.0, **kwargs):
"""
Scales the geometry to a new size by multiplying the ordinates
with the given x,y,z scale factors.
"""
if connections[self.db].ops.spatialite:
if z != 0.0:
raise NotImplementedError(
'SpatiaLite does not support 3D scaling.')
s = {
'procedure_fmt': '%(geo_col)s,%(x)s,%(y)s',
'procedure_args': {
'x': x,
'y': y
},
'select_field': GeomField(),
}
else:
s = {
'procedure_fmt': '%(geo_col)s,%(x)s,%(y)s,%(z)s',
'procedure_args': {
'x': x,
'y': y,
'z': z
},
'select_field': GeomField(),
}
return self._spatial_attribute('scale', s, **kwargs)
def snap_to_grid(self, *args, **kwargs):
"""
Snap all points of the input geometry to the grid. How the
geometry is snapped to the grid depends on how many arguments
were given:
- 1 argument : A single size to snap both the X and Y grids to.
- 2 arguments: X and Y sizes to snap the grid to.
- 4 arguments: X, Y sizes and the X, Y origins.
"""
if False in [isinstance(arg, (float,) + six.integer_types) for arg in args]:
raise TypeError('Size argument(s) for the grid must be a float or integer values.')
nargs = len(args)
if nargs == 1:
size = args[0]
procedure_fmt = '%(geo_col)s,%(size)s'
procedure_args = {'size': size}
elif nargs == 2:
xsize, ysize = args
procedure_fmt = '%(geo_col)s,%(xsize)s,%(ysize)s'
procedure_args = {'xsize': xsize, 'ysize': ysize}
elif nargs == 4:
xsize, ysize, xorigin, yorigin = args
procedure_fmt = '%(geo_col)s,%(xorigin)s,%(yorigin)s,%(xsize)s,%(ysize)s'
procedure_args = {'xsize': xsize, 'ysize': ysize,
'xorigin': xorigin, 'yorigin': yorigin}
else:
raise ValueError('Must provide 1, 2, or 4 arguments to `snap_to_grid`.')
s = {'procedure_fmt': procedure_fmt,
'procedure_args': procedure_args,
'select_field': GeomField(),
}
return self._spatial_attribute('snap_to_grid', s, **kwargs)
def _geom_attribute(self, func, tolerance=0.05, **kwargs):
"""
DRY routine for setting up a GeoQuerySet method that attaches a
Geometry attribute (e.g., `centroid`, `point_on_surface`).
"""
s = {'select_field': GeomField()}
if connections[self.db].ops.oracle:
s['procedure_fmt'] = '%(geo_col)s,%(tolerance)s'
s['procedure_args'] = {'tolerance': tolerance}
return self._spatial_attribute(func, s, **kwargs)
def reverse_geom(self, **kwargs):
"""
Reverses the coordinate order of the geometry, and attaches as a
`reverse` attribute on each element of this GeoQuerySet.
"""
s = {'select_field': GeomField()}
kwargs.setdefault('model_att', 'reverse_geom')
if connections[self.db].ops.oracle:
s['geo_field_type'] = LineStringField
return self._spatial_attribute('reverse', s, **kwargs)
def translate(self, x, y, z=0.0, **kwargs):
"""
Translates the geometry to a new location using the given numeric
parameters as offsets.
"""
s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s,%(z)s',
'procedure_args' : {'x' : x, 'y' : y, 'z' : z},
'select_field' : GeomField(),
}
return self._spatial_attribute('translate', s, **kwargs)
def scale(self, x, y, z=0.0, **kwargs):
"""
Scales the geometry to a new size by multiplying the ordinates
with the given x,y,z scale factors.
"""
s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s,%(z)s',
'procedure_args' : {'x' : x, 'y' : y, 'z' : z},
'select_field' : GeomField(),
}
return self._spatial_attribute('scale', s, **kwargs)
def add_to_query(self, query, alias, col, source, is_summary):
if hasattr(source, '_geom'):
# Doing additional setup on the Query object for spatial aggregates.
aggregate = getattr(query.aggregates_module, self.name)
# Adding a conversion class instance and any selection wrapping
# SQL (e.g., needed by Oracle).
if aggregate.conversion_class is GeomField:
query.extra_select_fields[alias] = GeomField()
if SpatialBackend.select:
query.custom_select[alias] = SpatialBackend.select
super(GeoAggregate, self).add_to_query(query, alias, col, source, is_summary)
def _geomset_attribute(self, func, geom, tolerance=0.05, **kwargs):
"""
DRY routine for setting up a GeoQuerySet method that attaches a
Geometry attribute and takes a Geoemtry parameter. This is used
for geometry set-like operations (e.g., intersection, difference,
union, sym_difference).
"""
s = {'geom_args' : ('geom',),
'select_field' : GeomField(),
'procedure_fmt' : '%(geo_col)s,%(geom)s',
'procedure_args' : {'geom' : geom},
}
if connections[self.db].ops.oracle:
s['procedure_fmt'] += ',%(tolerance)s'
s['procedure_args']['tolerance'] = tolerance
return self._spatial_attribute(func, s, **kwargs)
