1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
from __future__ import print_function
import sys
from vtkmodules.vtkCommonCore import (
vtkIdList,
vtkVariant,
)
from vtkmodules.vtkIOGeoJSON import vtkGeoJSONReader
def load_geojson(input_string, feature_properties={}):
'''Parses input_string with vtkGeoJSONReader, returns vtkPolyData
feature_properties is a dictionary of name-default_values
to attach as cell data in the returned vtkPolyData.
'''
reader = vtkGeoJSONReader()
#reader.DebugOn()
reader.StringInputModeOn()
reader.SetStringInput(input_string)
for name,default_value in feature_properties.items():
reader.AddFeatureProperty(name, default_value)
reader.Update()
return reader.GetOutput()
if __name__ == '__main__' :
# Use feature collection example taken from the geojson spec.
# Coped from http://geojson.org/geojson-spec.html (October 2014).
# Features are in/near the island of Summatra (in western Indonesia).
input_string = \
"""
{ "type": "FeatureCollection",
"features": [
{ "type": "Feature",
"geometry": {"type": "Point", "coordinates": [102.0, 0.5]},
"properties": {"prop0": "value0"}
},
{ "type": "Feature",
"geometry": {
"type": "LineString",
"coordinates": [
[102.0, 0.0], [103.0, 1.0], [104.0, 0.0], [105.0, 1.0]
]
},
"properties": {
"prop0": "value0",
"prop1": 0.0
}
},
{ "type": "Feature",
"geometry": {
"type": "Polygon",
"coordinates": [
[ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0],
[100.0, 1.0], [100.0, 0.0] ]
]
},
"properties": {
"prop0": "value0",
"prop1": {"this": "that"}
}
}
]
}
"""
prop0_default = vtkVariant('default')
feature_properties = {'prop0': prop0_default}
polydata = load_geojson(input_string, feature_properties)
if polydata is None:
print('Failed to read input string and return vtkPolyData')
sys.exit(1)
num_errors = 0
# Check cell counts
expected_verts = 1
expected_lines = 1
expected_polys = 1
num_verts = polydata.GetNumberOfVerts()
if num_verts != expected_verts:
print('Wrong number of verts: returned %s, should be %s' % \
(num_verts, expected_verts))
num_errors += 1
num_lines = polydata.GetNumberOfLines()
if num_lines != expected_lines:
print('Wrong number of lines: returned %s, should be %s' % \
(num_lines, expected_lines))
num_errors += 1
else:
# Check number of points in the (first) polyline
id_list = vtkIdList()
polydata.GetLines().GetCell(0, id_list)
if id_list.GetNumberOfIds() != 4:
print('Wrong number of points in line 0: returned %s, should be %s' % \
(id_list.GetNumberOfIds(), 4))
num_errors += 1
num_polys = polydata.GetNumberOfPolys()
if num_polys != expected_polys:
print('Wrong number of polys: returned %s, should be %s' % \
(num_polys, expected_polys))
num_errors += 1
else:
# Check number of points in the (first) polygon
id_list = vtkIdList()
polydata.GetPolys().GetCell(0, id_list)
if id_list.GetNumberOfIds() != 4:
print('Wrong number of points in poly 0: returned %s, should be %s' % \
(id_list.GetNumberOfIds(), 4))
num_errors += 1
# Check cell data
cell_data = polydata.GetCellData()
# All polydata generated from GeoJSON have feature-id array
feature_id_array = cell_data.GetAbstractArray('feature-id')
if feature_id_array is None:
print('feature-id array missing')
num_errors += 1
# Test case also specified a prop0 array
prop0_array = cell_data.GetAbstractArray('prop0')
if prop0_array is None:
print('prop0 array missing')
num_errors += 1
print('num_errors:', num_errors)
sys.exit(num_errors)
|
