Mapnik is an open source software library for rendering spatial data to maps and images. It allows for the creation of individual images or tiled maps for web publishing. Written in C++ with Python bindings, it uses OGC standards, GDAL/OGR, and other libraries. Styles and rendering rules are defined using XML files, and maps can be rendered to different formats like PNG or PDF using Python scripts.

1. INTRODUZIONE A MAPNIK
Luca Delucchi OSMit 2009

2. Mapnik è un software libero per la
rappresentazione di dati geografici
Permette la realizzazione di
immagini singole oppure di tile
per la pubblicazione sul web
Multipiattaforma
Linux - Mac OS X - Windows
Luca Delucchi OSMit 2009

3. Scritto in C++ con python
bindings che facilitano
l'utilizzo
Utilizza standard OGC,
librerie GDAL/OGR,
proj, agg e cairo
Utilizza l'algoritmo di Painter
per determinare l'ordine
degli elementi
Luca Delucchi OSMit 2009

4. Utilizzo
Script per il rendering: Regole per gli stili:
- per le immagini - file XML
- per le tile - python
- c++
Luca Delucchi OSMit 2009

5. Stampa: png
#!/usr/bin/python
from mapnik import *
import cairo
mapfile = "progetto.xml"
map_output= 'prova_dim.png'
m = Map(1192, 840)
projection = '+proj=latlong +datum=WGS84'
load_map(m, mapfile)
bbox = Envelope(Coord(9.04311180114746,
45.7490234375), Coord(12.0447950363159,
47.1829261779785))
m.zoom_to_box(bbox)
render_to_file(m, map_output, 'png')
Luca Delucchi OSMit 2009

6. Stampa: png
#!/usr/bin/python
from mapnik import *
import cairo
mapfile = 'progetto.xml'
map_output = 'mapfile.pdf'
projection = '+proj=latlong +datum=WGS84'
m = Map(1192, 840)
load_map(m, mapfile)
bbox = Envelope(9.470383644104, 43.2393798828125,
12.4720678329468, 44.673282623291)
mapnik_map.zoom_to_box(bbox)
file = open(map_output, 'wb')
surface = cairo.PDFSurface(file.name, m.width, m.height)
render(m, surface)
surface.finish()
Luca Delucchi OSMit 2009

7. File XML: map
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE Map>
<Map bgcolor="#b5d0d0" srs="+proj=merc +a=6378137
+b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0
+k=1.0 +units=m +nadgrids=@null +no_defs +over">
.................................................................................................
.................................................................................................
.................................................................................................
</Map>
Luca Delucchi OSMit 2009

8. File XML: raster layer
<Layer name="dem" status="on">
<StyleName>raster</StyleName>
<Datasource>
<Parameter name="type">gdal</Parameter>
<Parameter name="file">/path/al/file/</Parameter>
<Parameter name="format">tiff</Parameter>
</Datasource>
</Layer>
<Datasource>
<Parameter name="type">raster</Parameter>
<Parameter name="file">/path/file.tiff</Parameter>
<Parameter name="format">tiff</Parameter>
<Parameter name="lox">5.0</Parameter>
<Parameter name="loy">35.0</Parameter>
<Parameter name="hix">20.0</Parameter>
<Parameter name="hiy">50.0</Parameter>
</Datasource>
Luca Delucchi OSMit 2009

9. File XML: postgis layer
<Layer name="misc_boundaries" status="on"
srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0
+lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m
+nadgrids=@null +no_defs +over">
<StyleName>boundary</StyleName>
<Datasource>
<Parameter name="type">postgis</Parameter>
<Parameter name="user">utente</Parameter>
<Parameter name="dbname">italy</Parameter>
<Parameter name="password">****</Parameter>
<Parameter name="table">(select * from italy_line) as
road </Parameter>
<Parameter name="estimate_extent">...</Parameter>
<Parameter name="extent">833337,5432307,
1119564,5572109</Parameter>
</Datasource>
</Layer>
Luca Delucchi OSMit 2009

10. File XML: shape layer
<Layer name="coast-poly" status="on" srs="+proj=merc
+a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0
+y_0=0 +k=1.0 +units=m +nadgrids=@null +no_defs +over">
<StyleName>coast-poly</StyleName>
<Datasource>
<Parameter name="type">shape</Parameter>
<Parameter name="file">/path/al/file/</Parameter>
</Datasource>
</Layer>
Luca Delucchi OSMit 2009

11. File XML: point style
<Style name="amenity">
<Rule>
<Filter>[tourism]='viewpoint'</Filter>
<PointSymbolizer file="/path/file" type="png"
width="16" height="16" allow_overlap="true"/>
</Rule>
</Style>
<Style name="amenity">
<Rule>
<Filter>[tourism]='viewpoint'</Filter>
<PointSymbolizer width="16" height="16"
opacity=”0.5” allow_overlap="true"/>
</Rule>
</Style>
Luca Delucchi OSMit 2009

12. File XML: line style
<Style>
<Rule>
<Filter>[highway] = 'motorway'</Filter>
<LineSymbolizer>
<CssParameter name="stroke">
#666666</CssParameter>
<CssParameter name="stroke-width">
5</CssParameter>
<CssParameter name="stroke-dasharray">
8 - 3</CssParameter>
<CssParameter name="stroke-linejoin">
round</CssParameter>
<CssParameter name="stroke-opacity">
0.7</CssParameter>
</LineSymbolizer>
</Rule>
</Style>
Luca Delucchi OSMit 2009

13. File XML: line style
<Style name="aerialways">
<Rule>
<Filter>[aerialway] = 'cable_car'</Filter>
<LinePatternSymbolizer width="16" height="16"
type="png" file="/path/to/icon.png"/>
</Rule>
</Style>
Luca Delucchi OSMit 2009

14. File XML: polygon style
<Style name="world">
<Rule>
<Filter>[na2] = 'IT'</Filter>
<PolygonSymbolizer>
<CssParameter name="fill">white</CssParameter>
<CssParameter name="fill-opacity">
0.8</CssParameter>
</PolygonSymbolizer>
</Rule>
</Style>
<Style name="world">
<Rule>
<Filter>[na2] = 'IT'</Filter>
<PolygonPatternSymbolizer width="16" height="16"
type="png" file="/path/to/icon.png"/>
</Rule>
</Style>
Luca Delucchi OSMit 2009

15. File XML: building style
<Style name=”building”>
<BuildingSymbolizer>
<CssParameter name="fill">#000000</CssParameter>
<CssParameter name="fill-opacity">1</CssParameter>
<CssParameter name="height">8</CssParameter>
</BuildingSymbolizer>
</Style>
Luca Delucchi OSMit 2009

16. File XML: text & shield style
<Style name="autostrade_name">
<Rule>
<Filter>[highway] = 'motorway'</Filter>
<ShieldSymbolizer name="ref" face_name="DejaVu
Sans Bold" size="7" fill="#000000" placement="line"
file="/path/file" type="png" width="17" height="17"
spacing="100" min_distance="150"/>
</Rule>
</Style>
<Style>
<Rule>
<Filter>[popolazione] &gt;= 100000</Filter>
<TextSymbolizer name="toponimo" face_name=
"DejaVu Sans Book" size="15" fill="#000000"
halo_radius="2" allow_overlap="true"/>
</Rule>
</Style>
Luca Delucchi OSMit 2009

17. File XML: scaledenom style
<Style name="autostrade_name">
<Rule>
<Filter>[highway] = 'motorway'</Filter>
<MaxScaleDenominator>10000000
</MaxScaleDenominator>
<MinScaleDenominator>2000000
</MinScaleDenominator>
<ShieldSymbolizer name="ref" face_name="DejaVu
Sans Bold" size="7" fill="#000000" placement="line"
file="/path/file" type="png" width="17" height="17"
spacing="100" min_distance="150"/>
</Rule>
</Style>
Luca Delucchi OSMit 2009

18. File XML: filter style
<Filter>[highway] = 'primary'</Filter>
<Filter>[popolazione] &gt;= 30000 and [popolazione] &lt;
100000</Filter>
<Filter>([highway] = 'primary' or [highway] = 'primary_link'
or [highway] = 'trunk' or [highway] = 'trunk_link') and not
([tunnel] = 'yes' or [tunnel] = 'true' or [tunnel] = '1')</Filter>
Luca Delucchi OSMit 2009

19. File XML: raster style
<Style name="raster">
<Rule>
<RasterSymbolizer>
</RasterSymbolizer>
</Rule>
</Style>
Luca Delucchi OSMit 2009

20. This work is licensed under the Creative Commons Attribution-Noncommercial-Share Alike 2.5 Italy License.
To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/2.5/it/ or send a letter to
Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA.
Luca Delucchi OSMit 2009