scripts/generate_shields.py

#!/usr/bin/env python3

# Generate highway shields as SVG files in symbols/shields.

from __future__ import print_function
import copy, lxml.etree, math, os


def main():
    namespace = 'http://www.w3.org/2000/svg'
    svgns = '{' + namespace + '}'
    svgnsmap = {None: namespace}

    config = {}
    config['base'] = {}

    # font_height and font_width are determined by trial and error
    config['base']['rounded_corners'] = 2
    config['base']['font_height'] = 11
    config['base']['font_width'] = 0.85
    config['base']['padding_x'] = 8
    config['base']['padding_y'] = 2
    config['base']['stroke_width'] = 1

    # Fall back colours used if no colours are defined in road-colours.yaml for a road type.
    config['base']['fill'] = '#f1f1f1'
    config['base']['stroke_fill'] = '#c6c6c6'

    config['global'] = {}

    config['global']['types'] = ['valtatie', 'kantatie', 'seututie', 'yhdystie', 'eurooppatie']
    config['global']['max_width'] = 48
    config['global']['output_dir'] = '../symbols/shields/' # specified relative to the script location
    
    config['valtatie'] = {'fill': '#ff163c', 'stroke_fill': 'white'}
    config['kantatie'] = {'fill': '#ffd90f', 'stroke_fill': 'black', 'stroke_width': 0.5}
    config['seututie'] = {'fill': 'white', 'stroke_fill': 'black', 'stroke_width': 0.5}
    config['yhdystie'] = {'fill': '#005eb7', 'stroke_fill': 'white'}
    config['eurooppatie'] = {'fill': '#00997c', 'stroke_fill': 'white'}

    if not os.path.exists(os.path.dirname(config['global']['output_dir'])):
        os.makedirs(os.path.dirname(config['global']['output_dir']))

    height = 1
    shield_size = 'base'

    dirpath = os.path.join(os.path.dirname(__file__), config['global']['output_dir'])
    try:
        os.makedirs(dirpath)
    except FileExistsError:
        pass

    for width in range(1, config['global']['max_width'] + 1):
        for shield_type in config['global']['types']:

            # merge base config and specific styles
            vars = copy.deepcopy(config['base'])
            if shield_type in config:
                for option in config[shield_type]:
                    vars[option] = config[shield_type][option]

            shield_width = 2 * vars['padding_x'] + math.ceil(vars['font_width'] * width)
            shield_height = 2 * vars['padding_y'] + math.ceil(vars['font_height'] * height)

            svg = lxml.etree.Element('svg', nsmap=svgnsmap)
            svg.set('width', '100%')
            svg.set('height', '100%')
            svg.set('viewBox', '0 0 ' + str(shield_width    + vars['stroke_width']) + ' ' + str(shield_height + vars['stroke_width']))

            if vars['stroke_width'] > 0:
                offset_x = vars['stroke_width'] / 2.0
                offset_y = vars['stroke_width'] / 2.0
            else:
                offset_x = 0
                offset_y = 0

            background = lxml.etree.Element(svgns + 'rect')
            background.set('x', str(offset_x))
            background.set('y', str(offset_y))
            background.set('width', str(shield_width))
            background.set('height', str(shield_height))
            background.set('id', 'shield-background')
            background.set('style', 'fill:' + vars['fill'])
            svg.append(background)

            shield = lxml.etree.Element(svgns + 'rect')
            shield.set('x', str(offset_x + 0.5))
            shield.set('y', str(offset_y + 0.5))
            shield.set('width', str(shield_width - 1))
            shield.set('height', str(shield_height - 1))
            if vars['rounded_corners'] > 0:
                shield.set('rx', str(vars['rounded_corners']))
                shield.set('ry', str(vars['rounded_corners']))
            shield.set('id', 'shield')

            stroke = ''
            if vars['stroke_width'] > 0:
                stroke = 'stroke:' + vars['stroke_fill'] + ';stroke-width:' + str(vars['stroke_width']) + ';'

            shield.set('style', 'fill:' + vars['fill'] + ';' + stroke)

            svg.append(shield)

            filename = shield_type + '_' + str(width) + 'x' + str(height)
            if shield_size != 'base':
                filename = filename + '_' + shield_size

            filename = filename + '.svg'

            # save file
            try:
                shieldpath = os.path.join(os.path.dirname(__file__), config['global']['output_dir'] + filename)
                print('Writing', os.path.realpath(shieldpath))
                shieldfile = open(shieldpath, 'wb')
                shieldfile.write(lxml.etree.tostring(svg, encoding='utf-8', xml_declaration=True, pretty_print=True))
                shieldfile.close()
            except IOError:
                print('Could not save file ' + filename + '.')
                continue

if __name__ == "__main__":
    main()