mapnik/tests/python_tests/raster_symbolizer_test.py

#!/usr/bin/env python

from nose.tools import *
from utilities import execution_path, save_data, contains_word

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_dataraster_coloring():
    srs = '+init=epsg:32630'
    lyr = mapnik.Layer('dataraster')
    if 'gdal' in mapnik.DatasourceCache.instance().plugin_names():
        lyr.datasource = mapnik.Gdal(
            file = '../data/raster/dataraster.tif',
            band = 1,
            )
        lyr.srs = srs
        _map = mapnik.Map(256,256, srs)
        style = mapnik.Style()
        rule = mapnik.Rule()
        sym = mapnik.RasterSymbolizer()
        # Assigning a colorizer to the RasterSymbolizer tells the later
        # that it should use it to colorize the raw data raster
        sym.colorizer = mapnik.RasterColorizer(mapnik.COLORIZER_DISCRETE, mapnik.Color("transparent"))

        for value, color in [
            (  0, "#0044cc"),
            ( 10, "#00cc00"),
            ( 20, "#ffff00"),
            ( 30, "#ff7f00"),
            ( 40, "#ff0000"),
            ( 50, "#ff007f"),
            ( 60, "#ff00ff"),
            ( 70, "#cc00cc"),
            ( 80, "#990099"),
            ( 90, "#660066"),
            ( 200, "transparent"),
        ]:
            sym.colorizer.add_stop(value, mapnik.Color(color))
        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)
        # save a png somewhere so we can see it
        save_data('test_dataraster_coloring.png', im.tostring('png'))
        imdata = im.tostring()
        # we have some values in the [20,30) interval so check that they're colored
        assert contains_word('\xff\xff\x00\xff', imdata)

def test_dataraster_query_point():
    srs = '+init=epsg:32630'
    lyr = mapnik.Layer('dataraster')
    if 'gdal' in mapnik.DatasourceCache.instance().plugin_names():
        lyr.datasource = mapnik.Gdal(
            file = '../data/raster/dataraster.tif',
            band = 1,
            )
        lyr.srs = srs
        _map = mapnik.Map(256,256, srs)
        _map.layers.append(lyr)

        x, y = 556113.0,4381428.0 # center of extent of raster
        _map.zoom_all()
        features = _map.query_point(0,x,y).features
        assert len(features) == 1
        feat = features[0]
        center = feat.envelope().center()
        assert center.x==x and center.y==y, center
        value = feat['value']
        assert value == 18.0, value

        # point inside map extent but outside raster extent
        current_box = _map.envelope()
        current_box.expand_to_include(-427417,4477517)
        _map.zoom_to_box(current_box)
        features = _map.query_point(0,-427417,4477517).features
        assert len(features) == 0

        # point inside raster extent with nodata
        features = _map.query_point(0,126850,4596050).features
        assert len(features) == 0

def test_load_save_map():
    map = mapnik.Map(256,256)
    in_map = "../data/good_maps/raster_symbolizer.xml"
    try:
        mapnik.load_map(map, in_map)

        out_map = mapnik.save_map_to_string(map)
        assert 'RasterSymbolizer' in out_map
        assert 'RasterColorizer' in out_map
        assert 'stop' in out_map
    except RuntimeError, e:
        # only test datasources that we have installed
        if not 'Could not create datasource' in str(e):
            raise RuntimeError(str(e))

def test_raster_with_alpha_blends_correctly_with_background():
    WIDTH = 500
    HEIGHT = 500

    map = mapnik.Map(WIDTH, HEIGHT)
    WHITE = mapnik.Color(255, 255, 255)
    map.background = WHITE

    style = mapnik.Style()
    rule = mapnik.Rule()
    symbolizer = mapnik.RasterSymbolizer()
    #XXX: This fixes it, see http://trac.mapnik.org/ticket/759#comment:3
    #     (and remove comment when this test passes)
    #symbolizer.scaling="bilinear_old"

    rule.symbols.append(symbolizer)
    style.rules.append(rule)

    map.append_style('raster_style', style)

    map_layer = mapnik.Layer('test_layer')
    filepath = '../data/raster/white-alpha.png'
    if 'gdal' in mapnik.DatasourceCache.instance().plugin_names():
        map_layer.datasource = mapnik.Gdal(file=filepath)
        map_layer.styles.append('raster_style')
        map.layers.append(map_layer)

        map.zoom_all()

        mim = mapnik.Image(WIDTH, HEIGHT)

        mapnik.render(map, mim)
        save_data('test_raster_with_alpha_blends_correctly_with_background.png',
                  mim.tostring('png'))
        imdata = mim.tostring()
        # All white is expected
        assert contains_word('\xff\xff\xff\xff', imdata)

def test_raster_warping():
    lyrSrs = "+init=epsg:32630"
    mapSrs = '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs'
    lyr = mapnik.Layer('dataraster', lyrSrs)
    if 'gdal' in mapnik.DatasourceCache.instance().plugin_names():
        lyr.datasource = mapnik.Gdal(
            file = '../data/raster/dataraster.tif',
            band = 1,
            )
        sym = mapnik.RasterSymbolizer()
        sym.colorizer = mapnik.RasterColorizer(mapnik.COLORIZER_DISCRETE, mapnik.Color(255,255,0))
        rule = mapnik.Rule()
        rule.symbols.append(sym)
        style = mapnik.Style()
        style.rules.append(rule)
        _map = mapnik.Map(256,256, mapSrs)
        _map.append_style('foo', style)
        lyr.styles.append('foo')
        _map.layers.append(lyr)
        prj_trans = mapnik.ProjTransform(mapnik.Projection(mapSrs),
                                          mapnik.Projection(lyrSrs)) 
        _map.zoom_to_box(prj_trans.backward(lyr.envelope()))

        im = mapnik.Image(_map.width,_map.height)
        mapnik.render(_map, im)
        # save a png somewhere so we can see it
        save_data('test_raster_warping.png', im.tostring('png'))
        imdata = im.tostring()
        assert contains_word('\xff\xff\x00\xff', imdata)

def test_raster_warping_does_not_overclip_source():
    lyrSrs = "+init=epsg:32630"
    mapSrs = '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs'
    lyr = mapnik.Layer('dataraster', lyrSrs)
    if 'gdal' in mapnik.DatasourceCache.instance().plugin_names():
        lyr.datasource = mapnik.Gdal(
            file = '../data/raster/dataraster.tif',
            band = 1,
            )
        sym = mapnik.RasterSymbolizer()
        sym.colorizer = mapnik.RasterColorizer(mapnik.COLORIZER_DISCRETE, mapnik.Color(255,255,0))
        rule = mapnik.Rule()
        rule.symbols.append(sym)
        style = mapnik.Style()
        style.rules.append(rule)
        _map = mapnik.Map(256,256, mapSrs)
        _map.background=mapnik.Color('white')
        _map.append_style('foo', style)
        lyr.styles.append('foo')
        _map.layers.append(lyr)
        _map.zoom_to_box(mapnik.Box2d(3,42,4,43))

        im = mapnik.Image(_map.width,_map.height)
        mapnik.render(_map, im)
        # save a png somewhere so we can see it
        save_data('test_raster_warping_does_not_overclip_source.png',
                  im.tostring('png'))
        assert im.view(0,200,1,1).tostring()=='\xff\xff\x00\xff'

if __name__ == "__main__":
    setup()
    [eval(run)() for run in dir() if 'test_' in run]