django/django

"""
 This module is for the miscellaneous GEOS routines, particularly the
 ones that return the area, distance, and length.
"""

from ctypes import POINTER, c_double, c_int

from django.contrib.gis.geos.libgeos import GEOM_PTR, GEOSFuncFactory
from django.contrib.gis.geos.prototypes.errcheck import check_dbl, check_string
from django.contrib.gis.geos.prototypes.geom import geos_char_p

__all__ = ["geos_area", "geos_distance", "geos_length", "geos_isvalidreason"]


class DblFromGeom(GEOSFuncFactory):
    """
    Argument is a Geometry, return type is double that is passed
    in by reference as the last argument.
    """

    restype = c_int  # Status code returned
    errcheck = staticmethod(check_dbl)


# ### ctypes prototypes ###

# Area, distance, and length prototypes.
geos_area = DblFromGeom("GEOSArea", argtypes=[GEOM_PTR, POINTER(c_double)])
geos_distance = DblFromGeom(
    "GEOSDistance", argtypes=[GEOM_PTR, GEOM_PTR, POINTER(c_double)]
)
geos_length = DblFromGeom("GEOSLength", argtypes=[GEOM_PTR, POINTER(c_double)])
geos_isvalidreason = GEOSFuncFactory(
    "GEOSisValidReason", restype=geos_char_p, errcheck=check_string, argtypes=[GEOM_PTR]
)