app/django/contrib/gis/geos/prototypes/misc.py
changeset 323 ff1a9aa48cfd
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/contrib/gis/geos/prototypes/misc.py	Tue Oct 14 16:00:59 2008 +0000
@@ -0,0 +1,27 @@
+"""
+ This module is for the miscellaneous GEOS routines, particularly the
+ ones that return the area, distance, and length.
+"""
+from ctypes import c_int, c_double, POINTER
+from django.contrib.gis.geos.libgeos import lgeos, GEOM_PTR
+from django.contrib.gis.geos.prototypes.errcheck import check_dbl
+
+### ctypes generator function ###
+def dbl_from_geom(func, num_geom=1):
+    """
+    Argument is a Geometry, return type is double that is passed
+    in by reference as the last argument.
+    """
+    argtypes = [GEOM_PTR for i in xrange(num_geom)]
+    argtypes += [POINTER(c_double)]
+    func.argtypes = argtypes
+    func.restype = c_int # Status code returned
+    func.errcheck = check_dbl
+    return func
+
+### ctypes prototypes ###
+
+# Area, distance, and length prototypes.
+geos_area = dbl_from_geom(lgeos.GEOSArea)
+geos_distance = dbl_from_geom(lgeos.GEOSDistance, num_geom=2)
+geos_length = dbl_from_geom(lgeos.GEOSLength)