app/django/contrib/gis/geos/prototypes/misc.py
author Sverre Rabbelier <sverre@rabbelier.nl>
Tue, 26 May 2009 20:04:59 +0200
branchgae-fetch-limitation-fix
changeset 2315 29fea493cd56
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Use key_name instead of link_id Some entities do not have a link_id, but all entities are guaranteed to have a key_name (or an id).
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
323
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     1
"""
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     2
 This module is for the miscellaneous GEOS routines, particularly the
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     3
 ones that return the area, distance, and length.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     4
"""
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     5
from ctypes import c_int, c_double, POINTER
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     6
from django.contrib.gis.geos.libgeos import lgeos, GEOM_PTR
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     7
from django.contrib.gis.geos.prototypes.errcheck import check_dbl
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     8
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     9
### ctypes generator function ###
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    10
def dbl_from_geom(func, num_geom=1):
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    11
    """
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    12
    Argument is a Geometry, return type is double that is passed
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    13
    in by reference as the last argument.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    14
    """
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    15
    argtypes = [GEOM_PTR for i in xrange(num_geom)]
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    16
    argtypes += [POINTER(c_double)]
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    17
    func.argtypes = argtypes
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    18
    func.restype = c_int # Status code returned
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    19
    func.errcheck = check_dbl
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    20
    return func
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    21
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    22
### ctypes prototypes ###
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    23
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    24
# Area, distance, and length prototypes.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    25
geos_area = dbl_from_geom(lgeos.GEOSArea)
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    26
geos_distance = dbl_from_geom(lgeos.GEOSDistance, num_geom=2)
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    27
geos_length = dbl_from_geom(lgeos.GEOSLength)