from ctypes import POINTER, c_byte, c_double, c_int, c_uint
from django.contrib.gis.geos.libgeos import CS_PTR, GEOM_PTR, GEOSFuncFactory
from django.contrib.gis.geos.prototypes.errcheck import (
GEOSException, last_arg_byref,
)
# ## Error-checking routines specific to coordinate sequences. ##
def check_cs_op(result, func, cargs):
"Check the status code of a coordinate sequence operation."
if result == 0:
raise GEOSException('Could not set value on coordinate sequence')
else:
return result
def check_cs_get(result, func, cargs):
"Check the coordinate sequence retrieval."
check_cs_op(result, func, cargs)
# Object in by reference, return its value.
return last_arg_byref(cargs)
# ## Coordinate sequence prototype factory classes. ##
class CsInt(GEOSFuncFactory):
"For coordinate sequence routines that return an integer."
argtypes = [CS_PTR, POINTER(c_uint)]
restype = c_int
errcheck = staticmethod(check_cs_get)
class CsOperation(GEOSFuncFactory):
"For coordinate sequence operations."
restype = c_int
def __init__(self, *args, ordinate=False, get=False, **kwargs):
if get:
# Get routines have double parameter passed-in by reference.
errcheck = check_cs_get
dbl_param = POINTER(c_double)
else:
errcheck = check_cs_op
dbl_param = c_double
if ordinate:
# Get/Set ordinate routines have an extra uint parameter.
argtypes = [CS_PTR, c_uint, c_uint, dbl_param]
else:
argtypes = [CS_PTR, c_uint, dbl_param]
super().__init__(*args, **{**kwargs, 'errcheck': errcheck, 'argtypes': argtypes})
class CsOutput(GEOSFuncFactory):
restype = CS_PTR
@staticmethod
def errcheck(result, func, cargs):
if not result:
raise GEOSException(
'Error encountered checking Coordinate Sequence returned from GEOS '
'C function "%s".' % func.__name__
)
return result
# ## Coordinate Sequence ctypes prototypes ##
# Coordinate Sequence constructors & cloning.
cs_clone = CsOutput('GEOSCoordSeq_clone', argtypes=[CS_PTR])
create_cs = CsOutput('GEOSCoordSeq_create', argtypes=[c_uint, c_uint])
get_cs = CsOutput('GEOSGeom_getCoordSeq', argtypes=[GEOM_PTR])
# Getting, setting ordinate
cs_getordinate = CsOperation('GEOSCoordSeq_getOrdinate', ordinate=True, get=True)
cs_setordinate = CsOperation('GEOSCoordSeq_setOrdinate', ordinate=True)
# For getting, x, y, z
cs_getx = CsOperation('GEOSCoordSeq_getX', get=True)
cs_gety = CsOperation('GEOSCoordSeq_getY', get=True)
cs_getz = CsOperation('GEOSCoordSeq_getZ', get=True)
# For setting, x, y, z
cs_setx = CsOperation('GEOSCoordSeq_setX')
cs_sety = CsOperation('GEOSCoordSeq_setY')
cs_setz = CsOperation('GEOSCoordSeq_setZ')
# These routines return size & dimensions.
cs_getsize = CsInt('GEOSCoordSeq_getSize')
cs_getdims = CsInt('GEOSCoordSeq_getDimensions')
cs_is_ccw = GEOSFuncFactory('GEOSCoordSeq_isCCW', restype=c_int, argtypes=[CS_PTR, POINTER(c_byte)])