1 #

     2 # Copyright (c) 2008-2017 Thierry Florac <tflorac AT ulthar.net>

     3 # All Rights Reserved.

     4 #

     5 # This software is subject to the provisions of the Zope Public License,

     6 # Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.

     7 # THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED

     8 # WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

     9 # WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS

    10 # FOR A PARTICULAR PURPOSE.

    11 #

    12 

    13 __docformat__ = 'restructuredtext'

    14 

    15 

    16 # import standard library

    17 try:

    18     from osgeo.osr import SpatialReference, CoordinateTransformation

    19     have_gdal = True

    20 except ImportError:

    21     have_gdal = False

    22 

    23 # import interfaces

    24 

    25 # import packages

    26 from pyramid_rpc.jsonrpc import jsonrpc_method

    27 

    28 

    29 @jsonrpc_method(endpoint='gis')

    30 def transformPoint(request, point, from_projection, to_projection):

    31     """Transform point given in source projection to another projection

    32 

    33     :param point: point coordinates given as a mapping with 'longitude' and 'latitude' values

    34     :param from_projection: source coordinates system given as SRID

    35     :param to_projection: target coordinates system given as SRID

    36     :return: mapping with new 'point' key containing transformed coordinates, and 'projection'

    37         key containing SRID of result projection system

    38     """

    39     from_projection = int(from_projection)

    40     to_projection = int(to_projection)

    41     if (not have_gdal) or (from_projection == to_projection):

    42         return {'point': point,

    43                 'projection': from_projection}

    44     source = SpatialReference()

    45     source.ImportFromEPSG(from_projection)

    46     destination = SpatialReference()

    47     destination.ImportFromEPSG(to_projection)

    48     target = CoordinateTransformation(source, destination).TransformPoint(point['longitude'],

    49                                                                           point['latitude'])

    50     return {'point': {'longitude': target[0],

    51                       'latitude': target[1]},

    52             'projection': to_projection}

    53 

    54 

    55 @jsonrpc_method(endpoint='gis')

    56 def transformArea(request, area, from_projection, to_projection):

    57     """Transform area given in source projection to another projection

    58 

    59     :param area: area coordinates given as a mapping with 'x1', 'y1', 'x2', and 'y2' values

    60     :param from_projection: source coordinates system given as SRID

    61     :param to_projection: target coordinates system given as SRID

    62     :return: mapping with new 'area' key containing transformed coordinates, and 'projection'

    63         key containing SRID of result projection system

    64     """

    65     from_projection = int(from_projection)

    66     to_projection = int(to_projection)

    67     if (not have_gdal) or (from_projection == to_projection):

    68         return {'area': area,

    69                 'projection': from_projection}

    70     source = SpatialReference()

    71     source.ImportFromEPSG(from_projection)

    72     destination = SpatialReference()

    73     destination.ImportFromEPSG(to_projection)

    74     transformation = CoordinateTransformation(source, destination)

    75     point1 = transformation.TransformPoint(area['x1'], area['y1'])

    76     point2 = transformation.TransformPoint(area['x2'], area['y2'])

    77     return {'area': {'x1': point1[0],

    78                      'y1': point1[1],

    79                      'x2': point2[0],

    80                      'y2': point2[1]},

    81             'projection': to_projection}