mapnik/tests/python_tests/multi_tile_raster_test.py

#!/usr/bin/env python

from nose.tools import eq_
from utilities import execution_path, run_all
import os, mapnik

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('.'))

def test_multi_tile_policy():
    srs = '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs'
    lyr = mapnik.Layer('raster')
    if 'raster' in mapnik.DatasourceCache.plugin_names():
        lyr.datasource = mapnik.Raster(
            file = '../data/raster_tiles/${x}/${y}.tif',
            lox = -180,
            loy = -90,
            hix = 180,
            hiy = 90,
            multi = 1,
            tile_size = 256,
            x_width = 2,
            y_width = 2
            )
        lyr.srs = srs
        _map = mapnik.Map(256, 256, srs)
        style = mapnik.Style()
        rule = mapnik.Rule()
        sym = mapnik.RasterSymbolizer()
        rule.symbols.append(sym)
        style.rules.append(rule)
        _map.append_style('foo', style)
        lyr.styles.append('foo')
        _map.layers.append(lyr)
        _map.zoom_to_box(lyr.envelope())

        im = mapnik.Image(_map.width, _map.height)
        mapnik.render(_map, im)

        # test green chunk
        eq_(im.view(0,64,1,1).tostring(), '\x00\xff\x00\xff')
        eq_(im.view(127,64,1,1).tostring(), '\x00\xff\x00\xff')
        eq_(im.view(0,127,1,1).tostring(), '\x00\xff\x00\xff')
        eq_(im.view(127,127,1,1).tostring(), '\x00\xff\x00\xff')

        # test blue chunk
        eq_(im.view(128,64,1,1).tostring(), '\x00\x00\xff\xff')
        eq_(im.view(255,64,1,1).tostring(), '\x00\x00\xff\xff')
        eq_(im.view(128,127,1,1).tostring(), '\x00\x00\xff\xff')
        eq_(im.view(255,127,1,1).tostring(), '\x00\x00\xff\xff')

        # test red chunk
        eq_(im.view(0,128,1,1).tostring(), '\xff\x00\x00\xff')
        eq_(im.view(127,128,1,1).tostring(), '\xff\x00\x00\xff')
        eq_(im.view(0,191,1,1).tostring(), '\xff\x00\x00\xff')
        eq_(im.view(127,191,1,1).tostring(), '\xff\x00\x00\xff')

        # test magenta chunk
        eq_(im.view(128,128,1,1).tostring(), '\xff\x00\xff\xff')
        eq_(im.view(255,128,1,1).tostring(), '\xff\x00\xff\xff')
        eq_(im.view(128,191,1,1).tostring(), '\xff\x00\xff\xff')
        eq_(im.view(255,191,1,1).tostring(), '\xff\x00\xff\xff')

if __name__ == "__main__":
    setup()
    exit(run_all(eval(x) for x in dir() if x.startswith("test_")))