OSMTile

Python implementation for a OSM Map-Renderer

TODO

• Node rendering (Icons)
• Effects (icon fill, pattern fill, etc.)

Quick and dirty how-to

1. Create a PostgreSQL Database with PostGIS activated
2. Fetch a copy of imposm3
3. Get a OpenStreetMap data file (for example from Geofabrik, start with a small region!)
4. Import some OpenStreetMap data into the DB:

$ imposm import -connection postgis://user:password@host:port/database -mapping doc/imposm_mapping.yml -read /path/to/osm.pbf -write -deployproduction

5. Create a virtualenv and install packages:

mkvirtualenv -p /usr/bin/python3 osmtile
pip install -r requirements.txt

6. Render a map:

python render.py --config config/config.json 48.3849 10.8631 14

Layer config

Global

Global configuration for the map

Example:

{
    "global": {
        "background": "#f0f0f0",
        "projection": "merc",
        "min_zoom": 0,
        "max_zoom": 22,
        "area": {
            "xmin": -20037508.34,
            "ymin": -20037508.34,
            "xmax": 20037508.34,
            "ymax": 20037508.34
        },
        "database": {
            "user": "osm",
            "dbname": "osm"
        }
    }
}

• minzoom Minimal zoom level (usually 0, fit the world into viewport)
• maxzoom Maximal zoom level (usually 22, displays full detail)
• projection usually merc for spherical mercator
• area Mapping area in projected coordinates
  • xmin
  • ymin
  • xmax
  • ymax
• database
  • user
  • password
  • dbame
  • hostname
  • port
• background background color

Definitions

Fonts

Example:

{
    "fonts": {
        "country": {
            "face": "DejaVu Sans",
            "size": 50,
            "style": "regular",
            "weight": 800,
            "halo_size": 3
        },
        "road": {
            "face": "DejaVu Sans",
            "size": 14,
            "style": "regular",
            "weight": 400,
            "halo_size": 1
        }
    }
}

• Dict: key = short Name or string (filename) or array (list of filenames)
• Value: Dict
  • face
  • size
  • style (regular, italic)
  • weight
  • halo size

Colors

Example:

{
    "colors": {
        "road_residential": [0.8, 0.8, 0.8, 1.0],
        "road_motorway": [0.8, 0.8, 0.0, 1.0],
        "forest": [0.3, 0.9, 0.3, 1.0],
        "moor": [0.3, 0.3, 0.0, 1.0]
    }
}

• Dict: key = short Name or string (filename) or array (list of filenames)
• Value one of:
  • Array [r, g, b, a]
  • HTML Hex color: #rrggbbaa, shorthands allowed: #rgb. If alpha is skipped it is assumed as 1.0/fully opaque
  • Function:
    • darken(<color>, <percentage>)
    • lighten(<color>, <percentage>)
    • saturation(<color>, <percentage>)
    • alpha(<color>, <percentage>)

Icons

Example:

{
    "icons": {
        "forest": {
            "filename": "img/tree@2x.png",
            "colorize": "darken(forest, 20%)",
            "scale": 0.5
        },
        "moor": {
            "derive": "forest",
            "colorize": "moor"
        },
        "motorway": {
            "filename": "img/motorway@2x.png",
            "scale": 0.5,
            "split_positions": [5, 5]
        }
    }
}

• Dict: key = short Name or string (filename) or array (list of filenames)
• Value: Dict
  • filename (load from file, png or svg)
  • derive (derive from other icon)
  • colorize (use only alpha of icon and apply color or function)
  • scale (scale the image, used for @2x icons to facilitate retina rendering)
  • split_positions array of two pixel positions where to split the icon to fit text if used as shield, second value is pixels from the right boundary

Styles

Example:

{
    "styles": {
        "road_residential": {
            "fill_color": "road_residential",
            "stroke_color": "darken(road_residential, 20%)",
            "description_font": "road",
            "text_color": "darken(road_residential, 20%)",
            "halo_color": [1.0, 1.0, 1.0, 1.0]
        },
        "road_motorway": {
            "fill_color": "road_motorway",
            "stroke_color": "darken(road_motorway, 20%)",
            "description_font": "road",
            "text_color": "darken(road_motorway, 20%)",
            "halo_color": [1.0, 1.0, 1.0, 1.0],
            "shield_icon": "motorway"
        },
        "forest": {
            "fill_color": "forest",
            "font": "road",
            "text_color": "darken(forest, 20%)",
            "halo_color": "lighten(forest, 20%)",
            "fill_pattern_icon": "forest",
            "fill_pattern_spacing": 30
        }
    }
}

Value: Dict key = short name or string (filename) or array (list of filenames)

• fill_color polygon or line stroke fill color
• stroke_color polygon outline or stroke outline color
• description_font font to use for text
• text_color
• halo_color Text outline halo color to use
• fill_pattern_icon Fill the polygon with a sparse fill of this icon
• fill_pattern_spacing Pixels between renditions of the pattern icons
• fill_style one of solid, diagonally_hatched, horizontally_hatched, vertically_hatched, stippled, roughly_stippled, dashed or none, defaults to solid
• stroke_style one of solid, dashed, stippled, fanned, patterned
• stroke_pattern_icon icon to repeat on the stroke line if patterned has been selected
• stroke_pattern_spacing spacing in pixels between renditions of the pattern icons
• shield_icon render icon behind description text

Zoomlevels

{
    "layers": {
        "12": [
            {
                "name": "Forests",
                "db_table": "areas",
                "type": "polygon",
                "style": "forest",
                "filter": {
                    "designation": [
                        { "=": "forest" }
                    ]
                }
            },
            {
                "name": "Roads",
                "db_table": "roads",
                "type": "line",
                "text_column": "name",
                "style": "road_residential",
                "width": 5,
                "stroke": 1
            },
            {
                "name": "Motorways",
                "db_table": "motorways",
                "type": "line",
                "text_column": "name",
                "style": "road_motorway",
                "width": 9,
                "stroke": 2
            }
        ]
    }
}

• You can skip layers that will have the same config as a previous one.
• You have to define the first zoom level you want to support and the last one (even if the last is a duplicate)

Dict: key = level Value: array (see below) or string (filename)

Layer definition

If array item is a string then it defines a file to load, if it is a dict the layer definition is inline

• name
• db_table
• type one of
  • node (renders icons),
  • polygon (renders polygons),
  • line (renders lines of constant width)
• text_column
• style

Node type

• icon

Polygon type

• 3d make pseudo 3d shapes for buildings, bigger values are bigger effect
• stroke stroke width in pixels

Line type

• width width in pixels
• stroke stroke width in pixels

Filter

Array of Dicts

• Key: db field
• Value: Array of dict (or choices)
  • Key: operator (=, <=, >=, <, >, !=)
  • Value: operator value