def create_grid_map(width,height):
places_ds = mapnik.PointDatasource()
places_ds.add_point(143.10,-38.60,'Name','South East')
places_ds.add_point(142.48,-38.60,'Name','South West')
places_ds.add_point(142.48,-38.38,'Name','North West')
places_ds.add_point(143.10,-38.38,'Name','North East')
s = mapnik.Style()
r = mapnik.Rule()
#symb = mapnik.PointSymbolizer()
symb = mapnik.MarkersSymbolizer()
symb.allow_overlap = True
r.symbols.append(symb)
label = mapnik.TextSymbolizer(mapnik.Expression('[Name]'),
'DejaVu Sans Book',
10,
mapnik.Color('black')
)
label.allow_overlap = True
label.displacement = (0,-10)
#r.symbols.append(label)
s.rules.append(r)
lyr = mapnik.Layer('Places')
lyr.datasource = places_ds
lyr.styles.append('places_labels')
m = mapnik.Map(width,height)
m.append_style('places_labels',s)
m.layers.append(lyr)
return m
def test_render_grid():
places_ds = mapnik.PointDatasource()
places_ds.add_point(143.10,-38.60,'Name','South East')
places_ds.add_point(142.48,-38.60,'Name','South West')
places_ds.add_point(142.48,-38.38,'Name','North West')
places_ds.add_point(143.10,-38.38,'Name','North East')
s = mapnik.Style()
r = mapnik.Rule()
#symb = mapnik.PointSymbolizer()
symb = mapnik.MarkersSymbolizer()
symb.allow_overlap = True
r.symbols.append(symb)
label = mapnik.TextSymbolizer(mapnik.Expression('[Name]'),
'DejaVu Sans Book',
10,
mapnik.Color('black')
)
label.allow_overlap = True
label.displacement = (0,-10)
#r.symbols.append(label)
s.rules.append(r)
lyr = mapnik.Layer('Places')
lyr.datasource = places_ds
lyr.styles.append('places_labels')
m = mapnik.Map(256,256)
m.append_style('places_labels',s)
m.layers.append(lyr)
ul_lonlat = mapnik.Coord(142.30,-38.20)
lr_lonlat = mapnik.Coord(143.40,-38.80)
m.zoom_to_box(mapnik.Box2d(ul_lonlat,lr_lonlat))
grid = mapnik.render_grid(m,0,key='Name',resolution=4,fields=['Name'])
eq_(grid,grid_correct)
eq_(resolve(grid,0,0),None)
# check every pixel of the nw symbol
expected = {"Name": "North West"}
# top row
eq_(resolve(grid,23,9),expected)
eq_(resolve(grid,23,10),expected)
eq_(resolve(grid,23,11),expected)
# core
eq_(resolve(grid,24,8),expected)
eq_(resolve(grid,24,9),expected)
eq_(resolve(grid,24,10),expected)
eq_(resolve(grid,24,11),expected)
eq_(resolve(grid,24,12),expected)
eq_(resolve(grid,25,8),expected)
eq_(resolve(grid,25,9),expected)
eq_(resolve(grid,25,10),expected)
eq_(resolve(grid,25,11),expected)
eq_(resolve(grid,25,12),expected)
# bottom row
eq_(resolve(grid,26,9),expected)
eq_(resolve(grid,26,10),expected)
eq_(resolve(grid,26,11),expected)
def test_render_points():
if not mapnik.has_cairo(): return
# create and populate point datasource (WGS84 lat-lon coordinates)
places_ds = mapnik.PointDatasource()
places_ds.add_point(142.48,-38.38,'Name','Westernmost Point') # westernmost
places_ds.add_point(143.10,-38.60,'Name','Southernmost Point') # southernmost
# create layer/rule/style
s = mapnik.Style()
r = mapnik.Rule()
symb = mapnik.PointSymbolizer()
symb.allow_overlap = True
r.symbols.append(symb)
s.rules.append(r)
lyr = mapnik.Layer('Places','+proj=latlon +datum=WGS84')
lyr.datasource = places_ds
lyr.styles.append('places_labels')
# latlon bounding box corners
ul_lonlat = mapnik.Coord(142.30,-38.20)
lr_lonlat = mapnik.Coord(143.40,-38.80)
# render for different projections
projs = {
'latlon': '+proj=latlon +datum=WGS84',
'merc': '+proj=merc +datum=WGS84 +k=1.0 +units=m +over +no_defs',
'google': '+proj=merc +ellps=sphere +R=6378137 +a=6378137 +units=m',
'utm': '+proj=utm +zone=54 +datum=WGS84'
}
for projdescr in projs.iterkeys():
m = mapnik.Map(1000, 500, projs[projdescr])
m.append_style('places_labels',s)
m.layers.append(lyr)
p = mapnik.Projection(projs[projdescr])
m.zoom_to_box(p.forward(mapnik.Box2d(ul_lonlat,lr_lonlat)))
# Render to SVG so that it can be checked how many points are there with string comparison
svg_file = os.path.join(tempfile.gettempdir(),'%s.svg')
mapnik.render_to_file(m, svg_file)
num_points_present = len(places_ds.all_features())
svg = open(svg_file,'r').read()
num_points_rendered = svg.count('<image ')
eq_(num_points_present, num_points_rendered, "Not all points were rendered (%d instead of %d) at projection %s" % (num_points_rendered, num_points_present, projdescr))
# Append overlay-layers to the map
m.layers.append(lyr)
###
### START scale
###
# center of the image
label_x = xmin + ((xmax - xmin) / 2)
# bottom of the image
label_y = ymin + ((ymax - ymin) / 30)
# create PointDatasource
pds = mapnik.PointDatasource()
# place scale at the bottom-center of the map
pds.add_point(label_x, label_y, 'Name', "Scale: 1:" + str(m.scale_denominator()))
# create label symbolizers
if mapnik.mapnik_version() >= 800:
text = mapnik.TextSymbolizer(mapnik.Expression('[Name]'),'DejaVu Sans Bold',12,mapnik.Color('black'))
else:
text = mapnik.TextSymbolizer('Name','DejaVu Sans Bold',12,mapnik.Color('black'))
s3 = mapnik.Style()
r3 = mapnik.Rule()
r3.symbols.append(text)
s3.rules.append(r3)
