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import os
import mapnik
import pytest
from .utilities import execution_path
@pytest.fixture
def setup():
# All of the paths used are relative, if we run the tests
# from another directory we need to chdir()
os.chdir(execution_path('.'))
yield
if 'shape' in mapnik.DatasourceCache.plugin_names():
def test_query_tolerance(setup):
if not os.path.exists('../data/shp/arrows.shp'):
pytest.skip('Missing data')
srs = 'epsg:4326'
lyr = mapnik.Layer('test')
ds = mapnik.Shapefile(file='../data/shp/arrows.shp')
lyr.datasource = ds
lyr.srs = srs
_width = 256
_map = mapnik.Map(_width, _width, srs)
_map.layers.append(lyr)
# zoom determines tolerance
_map.zoom_all()
_map_env = _map.envelope()
tol = (_map_env.maxx - _map_env.minx) / _width * 3
# 0.046875 for arrows.shp and zoom_all
assert tol == 0.046875
# check point really exists
x, y = 2.0, 4.0
features = _map.query_point(0, x, y)
assert len(list(features)) == 1
# check inside tolerance limit
x = 2.0 + tol * 0.9
features = _map.query_point(0, x, y)
assert len(list(features)) == 1
# check outside tolerance limit
x = 2.0 + tol * 1.1
features = _map.query_point(0, x, y)
assert len(list(features)) == 0
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