python/lib/django_1_4/django/contrib/gis/gdal/prototypes/geom.py

   1 from ctypes import c_char_p, c_double, c_int, c_void_p, POINTER
   2 from django.contrib.gis.gdal.envelope import OGREnvelope
   3 from django.contrib.gis.gdal.libgdal import lgdal, GEOJSON
   4 from django.contrib.gis.gdal.prototypes.errcheck import check_bool, check_envelope
   5 from django.contrib.gis.gdal.prototypes.generation import (const_string_output,
   6     double_output, geom_output, int_output, srs_output, string_output, void_output)
   7
   8 ### Generation routines specific to this module ###
   9 def env_func(f, argtypes):
  10     "For getting OGREnvelopes."
  11     f.argtypes = argtypes
  12     f.restype = None
  13     f.errcheck = check_envelope
  14     return f
  15
  16 def pnt_func(f):
  17     "For accessing point information."
  18     return double_output(f, [c_void_p, c_int])
  19
  20 def topology_func(f):
  21     f.argtypes = [c_void_p, c_void_p]
  22     f.restype = c_int
  23     f.errchck = check_bool
  24     return f
  25
  26 ### OGR_G ctypes function prototypes ###
  27
  28 # GeoJSON routines, if supported.
  29 if GEOJSON:
  30     from_json = geom_output(lgdal.OGR_G_CreateGeometryFromJson, [c_char_p])
  31     to_json = string_output(lgdal.OGR_G_ExportToJson, [c_void_p], str_result=True)
  32     to_kml = string_output(lgdal.OGR_G_ExportToKML, [c_void_p, c_char_p], str_result=True)
  33 else:
  34     from_json = False
  35     to_json = False
  36     to_kml = False
  37
  38 # GetX, GetY, GetZ all return doubles.
  39 getx = pnt_func(lgdal.OGR_G_GetX)
  40 gety = pnt_func(lgdal.OGR_G_GetY)
  41 getz = pnt_func(lgdal.OGR_G_GetZ)
  42
  43 # Geometry creation routines.
  44 from_wkb = geom_output(lgdal.OGR_G_CreateFromWkb, [c_char_p, c_void_p, POINTER(c_void_p), c_int], offset=-2)
  45 from_wkt = geom_output(lgdal.OGR_G_CreateFromWkt, [POINTER(c_char_p), c_void_p, POINTER(c_void_p)], offset=-1)
  46 create_geom = geom_output(lgdal.OGR_G_CreateGeometry, [c_int])
  47 clone_geom = geom_output(lgdal.OGR_G_Clone, [c_void_p])
  48 get_geom_ref = geom_output(lgdal.OGR_G_GetGeometryRef, [c_void_p, c_int])
  49 get_boundary = geom_output(lgdal.OGR_G_GetBoundary, [c_void_p])
  50 geom_convex_hull = geom_output(lgdal.OGR_G_ConvexHull, [c_void_p])
  51 geom_diff = geom_output(lgdal.OGR_G_Difference, [c_void_p, c_void_p])
  52 geom_intersection = geom_output(lgdal.OGR_G_Intersection, [c_void_p, c_void_p])
  53 geom_sym_diff = geom_output(lgdal.OGR_G_SymmetricDifference, [c_void_p, c_void_p])
  54 geom_union = geom_output(lgdal.OGR_G_Union, [c_void_p, c_void_p])
  55
  56 # Geometry modification routines.
  57 add_geom = void_output(lgdal.OGR_G_AddGeometry, [c_void_p, c_void_p])
  58 import_wkt = void_output(lgdal.OGR_G_ImportFromWkt, [c_void_p, POINTER(c_char_p)])
  59
  60 # Destroys a geometry
  61 destroy_geom = void_output(lgdal.OGR_G_DestroyGeometry, [c_void_p], errcheck=False)
  62
  63 # Geometry export routines.
  64 to_wkb = void_output(lgdal.OGR_G_ExportToWkb, None, errcheck=True) # special handling for WKB.
  65 to_wkt = string_output(lgdal.OGR_G_ExportToWkt, [c_void_p, POINTER(c_char_p)])
  66 to_gml = string_output(lgdal.OGR_G_ExportToGML, [c_void_p], str_result=True)
  67 get_wkbsize = int_output(lgdal.OGR_G_WkbSize, [c_void_p])
  68
  69 # Geometry spatial-reference related routines.
  70 assign_srs = void_output(lgdal.OGR_G_AssignSpatialReference, [c_void_p, c_void_p], errcheck=False)
  71 get_geom_srs = srs_output(lgdal.OGR_G_GetSpatialReference, [c_void_p])
  72
  73 # Geometry properties
  74 get_area = double_output(lgdal.OGR_G_GetArea, [c_void_p])
  75 get_centroid = void_output(lgdal.OGR_G_Centroid, [c_void_p, c_void_p])
  76 get_dims = int_output(lgdal.OGR_G_GetDimension, [c_void_p])
  77 get_coord_dim = int_output(lgdal.OGR_G_GetCoordinateDimension, [c_void_p])
  78 set_coord_dim = void_output(lgdal.OGR_G_SetCoordinateDimension, [c_void_p, c_int], errcheck=False)
  79
  80 get_geom_count = int_output(lgdal.OGR_G_GetGeometryCount, [c_void_p])
  81 get_geom_name = const_string_output(lgdal.OGR_G_GetGeometryName, [c_void_p])
  82 get_geom_type = int_output(lgdal.OGR_G_GetGeometryType, [c_void_p])
  83 get_point_count = int_output(lgdal.OGR_G_GetPointCount, [c_void_p])
  84 get_point = void_output(lgdal.OGR_G_GetPoint, [c_void_p, c_int, POINTER(c_double), POINTER(c_double), POINTER(c_double)], errcheck=False)
  85 geom_close_rings = void_output(lgdal.OGR_G_CloseRings, [c_void_p], errcheck=False)
  86
  87 # Topology routines.
  88 ogr_contains = topology_func(lgdal.OGR_G_Contains)
  89 ogr_crosses = topology_func(lgdal.OGR_G_Crosses)
  90 ogr_disjoint = topology_func(lgdal.OGR_G_Disjoint)
  91 ogr_equals = topology_func(lgdal.OGR_G_Equals)
  92 ogr_intersects = topology_func(lgdal.OGR_G_Intersects)
  93 ogr_overlaps = topology_func(lgdal.OGR_G_Overlaps)
  94 ogr_touches = topology_func(lgdal.OGR_G_Touches)
  95 ogr_within = topology_func(lgdal.OGR_G_Within)
  96
  97 # Transformation routines.
  98 geom_transform = void_output(lgdal.OGR_G_Transform, [c_void_p, c_void_p])
  99 geom_transform_to = void_output(lgdal.OGR_G_TransformTo, [c_void_p, c_void_p])
 100
 101 # For retrieving the envelope of the geometry.
 102 get_envelope = env_func(lgdal.OGR_G_GetEnvelope, [c_void_p, POINTER(OGREnvelope)])
 103