nik4.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Nik4: Export image from mapnik
# Run it with -h to see the list of options
# Written by Ilya Zverev, licensed WTFPL

import mapnik
import sys
import os
import re
import argparse
import math
import tempfile
import logging
import codecs

try:
    import cairo
    HAS_CAIRO = True
except ImportError:
    HAS_CAIRO = False

VERSION = '1.7'
TILE_BUFFER = 128
IM_MONTAGE = 'montage'
EPSG_4326 = '+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs'
EPSG_3857 = ('+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')

proj_lonlat = mapnik.Projection(EPSG_4326)
proj_web_merc = mapnik.Projection(EPSG_3857)
transform_lonlat_webmerc = mapnik.ProjTransform(proj_lonlat, proj_web_merc)


def layer_bbox(m, names, proj_target, bbox=None):
    """Calculate extent of given layers and bbox"""
    for layer in (l for l in m.layers if l.name in names):
        # it may as well be a GPX layer in WGS84
        layer_proj = mapnik.Projection(layer.srs)
        box_trans = mapnik.ProjTransform(layer_proj, proj_target)
        lbbox = box_trans.forward(layer.envelope())
        if bbox:
            bbox.expand_to_include(lbbox)
        else:
            bbox = lbbox
    return bbox


def filter_layers(m, lst):
    """Leave only layers in list active, disable others"""
    for l in m.layers:
        l.active = l.name in lst


def select_layers(m, enable, disable):
    """Enable and disable layers in corresponding lists"""
    for l in m.layers:
        if l.name in enable:
            l.active = True
        if l.name in disable:
            l.active = False


def prepare_ozi(mbbox, mwidth, mheight, name, transform):
    """Create georeferencing file for OziExplorer"""
    def deg(value, is_lon):
        degrees = math.floor(abs(value))
        minutes = (abs(value) - degrees) * 60
        return '{:4d},{:3.5F},{}'.format(
            int(round(degrees)), minutes,
            ('W' if is_lon else 'S') if value < 0 else ('E' if is_lon else 'N'))

    ozipoint = ('Point{:02d},xy,     ,     ,in, deg,    ,        ,N,    ,        ,E' +
                ', grid,   ,           ,           ,N')
    bbox = transform.backward(mbbox)
    points = "\n".join([ozipoint.format(n) for n in range(3, 31)])
    header = '''OziExplorer Map Data File Version 2.2
Nik4
{name}
1 ,Map Code,
WGS 84,WGS 84,   0.0000,   0.0000,WGS 84
Reserved 1
Reserved 2
Magnetic Variation,,,E
Map Projection,Mercator,PolyCal,No,AutoCalOnly,No,BSBUseWPX,No
Point01,xy,    0,    0,in, deg,{top},{left}, grid,   ,           ,           ,N
Point02,xy, {width:4d}, {height:4d},in, deg,{bottom},{right}, grid,   ,           ,           ,N
{points}
Projection Setup,,,,,,,,,,
Map Feature = MF ; Map Comment = MC     These follow if they exist
Track File = TF      These follow if they exist
Moving Map Parameters = MM?    These follow if they exist
MM0,Yes
MMPNUM,4
MMPXY,1,0,0
'''.format(name=name,
           top=deg(bbox.maxy, False),
           left=deg(bbox.minx, True),
           width=mwidth - 1,
           height=mheight - 1,
           bottom=deg(bbox.miny, False),
           right=deg(bbox.maxx, True),
           points=points)
    return ''.join([
        header,
        "MMPXY,2,{},0\n".format(mwidth),
        "MMPXY,3,{},{}\n".format(mwidth, mheight),
        "MMPXY,4,0,{}\n".format(mheight),
        'MMPLL,1,{:4.6f},{:4.6f}\n'.format(bbox.minx, bbox.maxy),
        'MMPLL,2,{:4.6f},{:4.6f}\n'.format(bbox.maxx, bbox.maxy),
        'MMPLL,3,{:4.6f},{:4.6f}\n'.format(bbox.maxx, bbox.miny),
        'MMPLL,4,{:4.6f},{:4.6f}\n'.format(bbox.minx, bbox.miny),
        "MM1B,{}\n".format((mbbox.maxx - mbbox.minx) / mwidth * math.cos(
            math.radians(bbox.center().y))),
        "MOP,Map Open Position,0,0\n",
        "IWH,Map Image Width/Height,{},{}\n".format(mwidth, mheight),
    ])


def prepare_wld(bbox, mwidth, mheight):
    """Create georeferencing world file"""
    pixel_x_size = (bbox.maxx - bbox.minx) / mwidth
    pixel_y_size = (bbox.maxy - bbox.miny) / mheight
    left_pixel_center_x = bbox.minx + pixel_x_size * 0.5
    top_pixel_center_y = bbox.maxy - pixel_y_size * 0.5
    return ''.join(["{:.8f}\n".format(n) for n in [
        pixel_x_size, 0.0,
        0.0, -pixel_y_size,
        left_pixel_center_x, top_pixel_center_y
    ]])


def write_metadata(bbox, mwidth, mheight, transform, img_output_file, wld_file=None, ozi_file=None):
    """Write worldfile and/or OZI file if required.

    Parameters
    ----------
    bbox: mapnik.Box2d
        bounding box of the map
    mwidth : int
        width of the image
    mheight : int
        height of the image
    transform : mapnik.ProjTransform
        transformation from EPSG:4326 to the target projection
    img_output_file : str
        image output path (required for OZI file)
    wld : file
        file pointer to the world file to be written (or None if non has to be written)
    ozi : file
        file pointer to the OZI file to be written (or None if non has to be written)
    """
    if ozi_file:
        ozi_file.write(prepare_ozi(bbox, mwidth, mheight, img_output_file, transform))
    if wld_file:
        wld_file.write(prepare_wld(bbox, mwidth, mheight))


def parse_url(url, options):
    """Parse map URL into options map"""
    lat = None
    lon = None
    zoom = None
    m = re.search(r'[#/=]([0-9]{1,2})/(-?[0-9]{1,2}\.[0-9]+)/(-?[0-9]{1,3}\.[0-9]+)', url)
    if m:
        zoom = int(m.group(1))
        lat = float(m.group(2))
        lon = float(m.group(3))
    else:
        m = re.search(r'lat=(-[0-9]{1,2}\.[0-9]+)', url, flags=re.IGNORECASE)
        if m:
            lat = float(m.group(1))
        m = re.search(r'lon=(-[0-9]{1,3}\.[0-9]+)', url, flags=re.IGNORECASE)
        if m:
            lon = float(m.group(1))
        m = re.search(r'zoom=([0-9]{1,2})', url, flags=re.IGNORECASE)
        if m:
            zoom = int(m.group(1))
    if zoom and not options.zoom:
        options.zoom = zoom
    if lat and lon and not options.center:
        options.center = [lon, lat]
    if (not options.size and not options.size_px and not options.paper
            and not options.fit and not options.bbox):
        options.size_px = [1280, 1024]


def get_paper_size(name):
    """Returns paper size for name, [long, short] sides in mm"""
    # ISO A*
    m = re.match(r'^a?(\d)$', name)
    if m:
        return [math.floor(1000 / 2**((2*int(m.group(1)) - 1) / 4.0) + 0.2),
                math.floor(1000 / 2**((2*(int(m.group(1)) + 1) - 1) / 4.0) + 0.2)]
    # ISO B*
    m = re.match(r'^b(\d)$', name)
    if m:
        return [math.floor(1000 / 2**((int(m.group(1)) - 1) / 2.0) + 0.2),
                math.floor(1000 / 2**(int(m.group(1)) / 2.0) + 0.2)]
    # German extensions
    if name == '4a0':
        return [2378, 1682]
    if name == '2a0':
        return [1682, 1189]
    # US Legal
    if re.match(r'^leg', name):
        return [355.6, 215.9]
    # US Letter
    if re.match(r'^l', name):
        return [279.4, 215.9]
    # Cards
    if re.match(r'^c(?:re|ar)d', name):
        return [85.6, 54]
    return None


def xml_vars(style, variables):
    """Replace ${name:default} from style with variables[name] or 'default'"""
    # Convert variables to a dict
    v = {}
    for kv in variables:
        keyvalue = kv.split('=', 1)
        if len(keyvalue) > 1:
            v[keyvalue[0]] = keyvalue[1].replace('&', '&amp;').replace(
                '<', '&lt;').replace('>', '&gt;').replace(
                '"', '&quot;').replace("'", '&#39;')
    if not v:
        return style
    # Scan all variables in style
    r = re.compile(r'\$\{([a-z0-9_]+)(?::([^}]*))?\}')
    rstyle = ''
    last = 0
    for m in r.finditer(style):
        if m.group(1) in v:
            value = v[m.group(1)]
        elif m.group(2) is not None:
            value = m.group(2)
        else:
            raise Exception('Found required style parameter: ' + m.group(1))
        rstyle = rstyle + style[last:m.start()] + value
        last = m.end()
    if last < len(style):
        rstyle = rstyle + style[last:]
    return rstyle


def reenable_layers(style, layers):
    """Remove status=off from layers we need."""
    layer_select = '|'.join([l.replace('\\', '\\\\').replace('|', '\\|')
                             .replace('.', '\\.').replace('+', '\\+')
                             .replace('*', '\\*') for l in layers])
    style = re.sub(
        r'(<Layer[^>]+name=["\'](?:{})["\'][^>]+)status=["\']off["\']'.format(layer_select),
        r'\1', style, flags=re.DOTALL)
    style = re.sub(
        r'(<Layer[^>]+)status=["\']off["\']([^>]+name=["\'](?:{})["\'])'.format(layer_select),
        r'\1\2', style, flags=re.DOTALL)
    return style


def parse_layers_string(layers):
    if not layers:
        return []
    return [l1 for l1 in (l.strip() for l in layers.split(',')) if l1]


def add_fonts(path):
    if os.path.exists(path):
        mapnik.register_fonts(path)
    else:
        raise Exception('The directory "{p}" does not exists'.format(p=path))


def correct_scale(bbox, scale, bbox_web_merc, bbox_target):
    # correct scale if output projection is not EPSG:3857
    x_dist_merc = bbox_web_merc.maxx - bbox_web_merc.minx
    x_dist_target = bbox.maxx - bbox.minx
    return scale * (x_dist_target / x_dist_merc)


def run(options):
    dim_mm = None
    scale = None
    size = None
    bbox = None
    rotate = not options.norotate

    if (options.ozi and options.projection.lower() != 'epsg:3857'
            and options.projection != EPSG_3857):
        raise Exception('Ozi map file output is only supported for Web Mercator (EPSG:3857). ' +
                        'Please remove --projection.')

    if options.url:
        parse_url(options.url, options)

    # format should not be empty
    if options.fmt:
        fmt = options.fmt.lower()
    elif '.' in options.output:
        fmt = options.output.split('.')[-1].lower()
    else:
        fmt = 'png256'

    need_cairo = fmt in ['svg', 'pdf']

    # output projection
    if options.projection.isdigit():
        proj_target = mapnik.Projection('+init=epsg:{}'.format(options.projection))
    else:
        proj_target = mapnik.Projection(options.projection)
    transform = mapnik.ProjTransform(proj_lonlat, proj_target)

    # get image size in millimeters
    if options.paper:
        portrait = False
        if options.paper[0] == '-':
            portrait = True
            rotate = False
            options.paper = options.paper[1:]
        elif options.paper[0] == '+':
            rotate = False
            options.paper = options.paper[1:]
        else:
            rotate = True
        dim_mm = get_paper_size(options.paper.lower())
        if not dim_mm:
            raise Exception('Incorrect paper format: ' + options.paper)
        if portrait:
            dim_mm = [dim_mm[1], dim_mm[0]]
    elif options.size:
        dim_mm = options.size
    if dim_mm and options.margin:
        dim_mm[0] = max(0, dim_mm[0] - options.margin * 2)
        dim_mm[1] = max(0, dim_mm[1] - options.margin * 2)

    # ppi and scale factor are the same thing
    if options.ppi:
        ppmm = options.ppi / 25.4
        scale_factor = options.ppi / 90.7
    else:
        scale_factor = options.factor
        ppmm = 90.7 / 25.4 * scale_factor

    # svg / pdf can be scaled only in cairo mode
    if scale_factor != 1 and need_cairo and not HAS_CAIRO:
        logging.error('Warning: install pycairo for using --factor or --ppi')
        scale_factor = 1
        ppmm = 90.7 / 25.4

    # convert physical size to pixels
    if options.size_px:
        size = options.size_px
    elif dim_mm:
        size = [int(round(dim_mm[0] * ppmm)), int(round(dim_mm[1] * ppmm))]

    if size and size[0] + size[1] <= 0:
        raise Exception('Both dimensions are less or equal to zero')

    if options.bbox:
        bbox = options.bbox

    # scale can be specified with zoom or with 1:NNN scale
    fix_scale = False
    if options.zoom:
        scale = 2 * 3.14159 * 6378137 / 2 ** (options.zoom + 8) / scale_factor
    elif options.scale:
        scale = options.scale * 0.00028 / scale_factor
        # Now we have to divide by cos(lat), but we might not know latitude at this point
        # TODO: division should only happen for EPSG:3857 or not at all
        if options.center:
            scale = scale / math.cos(math.radians(options.center[1]))
        elif options.bbox:
            scale = scale / math.cos(math.radians((options.bbox[3] + options.bbox[1]) / 2))
        else:
            fix_scale = True

    # all calculations are in EPSG:3857 projection (it's easier)
    if bbox:
        bbox = transform.forward(mapnik.Box2d(*bbox))
        bbox_web_merc = transform_lonlat_webmerc.forward(mapnik.Box2d(*(options.bbox)))
        if scale:
            scale = correct_scale(bbox, scale, bbox_web_merc, bbox)

    # calculate bbox through center, zoom and target size
    if not bbox and options.center and size and size[0] > 0 and size[1] > 0 and scale:
        # We don't know over which latitude range the bounding box spans, so we
        # first do everything in Web Mercator.
        center = transform_lonlat_webmerc.forward(mapnik.Coord(*options.center))
        w = size[0] * scale / 2
        h = size[1] * scale / 2
        bbox_web_merc = mapnik.Box2d(center.x-w, center.y-h, center.x+w, center.y+h)
        bbox = transform_lonlat_webmerc.backward(bbox_web_merc)
        bbox = transform.forward(bbox)
        # now correct the scale
        scale = correct_scale(bbox, scale, bbox_web_merc, bbox)
        center = transform.forward(mapnik.Coord(*options.center))
        w = size[0] * scale / 2
        h = size[1] * scale / 2
        bbox = mapnik.Box2d(center.x-w, center.y-h, center.x+w, center.y+h)

    # reading style xml into memory for preprocessing
    if options.style == '-':
        style_xml = sys.stdin.read()
        style_path = ''
    else:
        with codecs.open(options.style, 'r', 'utf-8') as style_file:
            style_xml = style_file.read()
        style_path = os.path.dirname(options.style)
    if options.base:
        style_path = options.base
    if options.vars:
        style_xml = xml_vars(style_xml, options.vars)
    if options.layers or options.add_layers:
        style_xml = reenable_layers(
            style_xml, parse_layers_string(options.layers) +
            parse_layers_string(options.add_layers))

    # for layer processing we need to create the Map object
    m = mapnik.Map(100, 100)  # temporary size, will be changed before output
    mapnik.load_map_from_string(m, style_xml.encode("utf-8"), False, style_path)
    m.srs = proj_target.params()

    # register non-standard fonts
    if options.fonts:
        for f in options.fonts:
            add_fonts(f)

    # get bbox from layer extents
    if options.fit:
        bbox = layer_bbox(m, options.fit.split(','), proj_target, bbox)
        # here's where we can fix scale, no new bboxes below
        if bbox and fix_scale:
            scale = scale / math.cos(math.radians(transform.backward(bbox.center()).y))
        bbox_web_merc = transform_lonlat_webmerc.forward(transform.backward(bbox))
        if scale:
            scale = correct_scale(bbox, scale, bbox_web_merc, bbox)
        # expand bbox with padding in mm
        if bbox and options.padding and (scale or size):
            if scale:
                tscale = scale
            else:
                tscale = min((bbox.maxx - bbox.minx) / max(size[0], 0.01),
                             (bbox.maxy - bbox.miny) / max(size[1], 0.01))
            bbox.pad(options.padding * ppmm * tscale)

    # bbox should be specified by this point
    if not bbox:
        raise Exception('Bounding box was not specified in any way')

    # rotate image to fit bbox better
    if rotate and size:
        portrait = bbox.maxy - bbox.miny > bbox.maxx - bbox.minx
        # take into consideration zero values, which mean they should be calculated from bbox
        if (size[0] == 0 or size[0] > size[1]) and portrait:
            size = [size[1], size[0]]

    # calculate pixel size from bbox and scale
    if not size:
        if scale:
            size = [int(round(abs(bbox.maxx - bbox.minx) / scale)),
                    int(round(abs(bbox.maxy - bbox.miny) / scale))]
        else:
            raise Exception('Image dimensions or scale were not specified in any way')
    elif size[0] == 0:
        size[0] = int(round(size[1] * (bbox.maxx - bbox.minx) / (bbox.maxy - bbox.miny)))
    elif size[1] == 0:
        size[1] = int(round(size[0] / (bbox.maxx - bbox.minx) * (bbox.maxy - bbox.miny)))

    if options.output == '-' or (need_cairo and (options.tiles_x > 1 or options.tiles_y > 1)):
        options.tiles_x = 1
        options.tiles_y = 1
    max_img_size = max(size[0] / options.tiles_x, size[1] / options.tiles_y)
    if max_img_size > 16384:
        larger_part = 'a larger value for ' if options.tiles_x > 1 or options.tiles_y > 1 else ''
        raise Exception('Image size exceeds mapnik limit ({} > {}), use {}--tiles'.format(
           max_img_size, 16384, larger_part))

    # add / remove some layers
    if options.layers:
        filter_layers(m, parse_layers_string(options.layers))
    if options.add_layers or options.hide_layers:
        select_layers(m, parse_layers_string(options.add_layers),
                      parse_layers_string(options.hide_layers))

    logging.debug('scale=%s', scale)
    logging.debug('scale_factor=%s', scale_factor)
    logging.debug('size=%s,%s', size[0], size[1])
    logging.debug('bbox=%s', bbox)
    logging.debug('bbox_wgs84=%s', transform.backward(bbox) if bbox else None)
    logging.debug('layers=%s', ','.join([l.name for l in m.layers if l.active]))

    # export image
    m.aspect_fix_mode = mapnik.aspect_fix_mode.GROW_BBOX
    m.resize(size[0], size[1])
    m.zoom_to_box(bbox)
    logging.debug('m.envelope(): {}'.format(m.envelope()))

    outfile = options.output
    if options.output == '-':
        outfile = tempfile.TemporaryFile(mode='w+b')

    if need_cairo:
        if HAS_CAIRO:
            if fmt == 'svg':
                surface = cairo.SVGSurface(outfile, size[0], size[1])
            else:
                surface = cairo.PDFSurface(outfile, size[0], size[1])
            mapnik.render(m, surface, scale_factor, 0, 0)
            surface.finish()
        else:
            mapnik.render_to_file(m, outfile, fmt)
        write_metadata(m.envelope(), size[0], size[1], transform, options.output,
                       options.wld, options.ozi)
    else:
        if options.tiles_x == options.tiles_y == 1:
            im = mapnik.Image(size[0], size[1])
            mapnik.render(m, im, scale_factor)
            im.save(outfile, fmt)
            write_metadata(m.envelope(), size[0], size[1], transform, options.output,
                           options.wld, options.ozi)
        else:
            # we cannot make mapnik calculate scale for us, so fixing aspect ratio outselves
            rdiff = (bbox.maxx-bbox.minx) / (bbox.maxy-bbox.miny) - size[0] / size[1]
            if rdiff > 0:
                bbox.height((bbox.maxx - bbox.minx) * size[1] / size[0])
            elif rdiff < 0:
                bbox.width((bbox.maxy - bbox.miny) * size[0] / size[1])
            scale = (bbox.maxx - bbox.minx) / size[0]
            width = max(32, int(math.ceil(1.0 * size[0] / options.tiles_x)))
            height = max(32, int(math.ceil(1.0 * size[1] / options.tiles_y)))
            m.resize(width, height)
            m.buffer_size = TILE_BUFFER
            tile_cnt = [int(math.ceil(1.0 * size[0] / width)),
                        int(math.ceil(1.0 * size[1] / height))]
            logging.debug('tile_count=%s %s', tile_cnt[0], tile_cnt[1])
            logging.debug('tile_size=%s,%s', width, height)
            tmp_tile = '{:02d}_{:02d}_{}'
            tile_files = []
            for row in range(0, tile_cnt[1]):
                for column in range(0, tile_cnt[0]):
                    logging.debug('tile=%s,%s', row, column)
                    tile_bbox = mapnik.Box2d(
                        bbox.minx + 1.0 * width * scale * column,
                        bbox.maxy - 1.0 * height * scale * row,
                        bbox.minx + 1.0 * width * scale * (column + 1),
                        bbox.maxy - 1.0 * height * scale * (row + 1))
                    tile_size = [
                        width if column < tile_cnt[0] - 1 else size[0] - width * (tile_cnt[0] - 1),
                        height if row < tile_cnt[1] - 1 else size[1] - height * (tile_cnt[1] - 1)]
                    m.zoom_to_box(tile_bbox)
                    im = mapnik.Image(tile_size[0], tile_size[1])
                    mapnik.render(m, im, scale_factor)
                    tile_name = tmp_tile.format(row, column, options.output)
                    im.save(tile_name, fmt)
                    if options.just_tiles:
                        # write ozi/wld for a tile if needed
                        if '.' not in tile_name:
                            tile_basename = tile_name + '.'
                        else:
                            tile_basename = tile_name[0:tile_name.rindex('.')+1]
                        if options.ozi:
                            with open(tile_basename + 'ozi', 'w') as f:
                                f.write(prepare_ozi(tile_bbox, tile_size[0], tile_size[1],
                                                    tile_basename + '.ozi', transform))
                        if options.wld:
                            with open(tile_basename + 'wld', 'w') as f:
                                f.write(prepare_wld(tile_bbox, tile_size[0], tile_size[1]))
                    else:
                        tile_files.append(tile_name)
            if not options.just_tiles:
                # join tiles and remove them if joining succeeded
                import subprocess
                result = subprocess.call([
                    IM_MONTAGE, '-geometry', '+0+0', '-tile',
                    '{}x{}'.format(tile_cnt[0], tile_cnt[1])] +
                    tile_files + [options.output])
                if result == 0:
                    for tile in tile_files:
                        os.remove(tile)
                    write_metadata(bbox, size[0], size[1], transform, options.output,
                                   options.wld, options.ozi)

    if options.output == '-':
        if sys.platform == "win32":
            # fix binary output on windows
            import msvcrt
            msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)

        outfile.seek(0)
        sys.stdout.write(outfile.read())
        outfile.close()


if __name__ == "__main__":
    parser = argparse.ArgumentParser(
        description='Nik4 {}: Tile-aware mapnik image renderer'.format(VERSION))
    parser.add_argument('--version', action='version', version='Nik4 {}'.format(VERSION))
    parser.add_argument('-z', '--zoom', type=float, help='Target zoom level')
    parser.add_argument('-p', '--ppi', '--dpi', type=float,
                        help='Pixels per inch (alternative to scale)')
    parser.add_argument('--factor', type=float, default=1,
                        help='Scale factor (affects ppi, default=1)')
    parser.add_argument('-s', '--scale', type=float,
                        help='Scale as in 1:100000 (specifying ppi is recommended)')
    parser.add_argument('-b', '--bbox', nargs=4, type=float,
                        metavar=('Xmin', 'Ymin', 'Xmax', 'Ymax'), help='Bounding box')
    parser.add_argument('-a', '--paper',
                        help='Paper format: -a +4 for landscape A4, -a -4 for portrait A4, ' +
                        '-a letter for autorotated US Letter')
    parser.add_argument('-d', '--size', nargs=2, metavar=('W', 'H'), type=int,
                        help='Target dimensions in mm (one 0 allowed)')
    parser.add_argument('-x', '--size-px', nargs=2, metavar=('W', 'H'), type=int,
                        help='Target dimensions in pixels (one 0 allowed)')
    parser.add_argument('--norotate', action='store_true', default=False,
                        help='Do not swap width and height for bbox')
    parser.add_argument('-m', '--margin', type=int,
                        help='Amount in mm to reduce paper size')
    parser.add_argument('-c', '--center', nargs=2, metavar=('X', 'Y'), type=float,
                        help='Center of an image')

    parser.add_argument('--fit', help='Fit layers in the map, comma-separated')
    parser.add_argument('--padding', type=int, default=5,
                        help='Margin for layers in --fit (default=5), mm')
    parser.add_argument('--layers', help='Map layers to render, comma-separated')
    parser.add_argument('--add-layers', help='Map layers to include, comma-separated')
    parser.add_argument('--hide-layers', help='Map layers to hide, comma-separated')

    parser.add_argument('-P', '--projection', default=EPSG_3857,
                        help='EPSG code as 1234 (without prefix "EPSG:" or Proj4 string')

    parser.add_argument('--url', help='URL of a map to center on')
    parser.add_argument('--ozi', type=argparse.FileType('w'), help='Generate ozi map file')
    parser.add_argument('--wld', type=argparse.FileType('w'), help='Generate world file')
    parser.add_argument('-t', '--tiles', default='1',
                        help='Write N×N (--tiles N) or N×M (--tiles NxM) tiles, '
                        'then join using imagemagick')
    parser.add_argument('--just-tiles', action='store_true', default=False,
                        help='Do not join tiles, instead write ozi/wld file for each')
    parser.add_argument('-v', '--debug', action='store_true', default=False,
                        help='Display calculated values')
    parser.add_argument('-f', '--format', dest='fmt',
                        help='Target file format (by default looks at extension)')
    parser.add_argument('--base',
                        help='Base path for style file, in case it\'s piped to stdin')
    parser.add_argument('--vars', nargs='*',
                        help='List of variables (name=value) to substitute in ' +
                        'style file (use ${name:default})')
    parser.add_argument('--fonts', nargs='*',
                        help='List of full path to directories containing fonts')
    parser.add_argument('style', help='Style file for mapnik')
    parser.add_argument('output', help='Resulting image file')
    options = parser.parse_args()

    options.tiles_x = 0
    options.tiles_y = 0

    if options.tiles:
        if options.tiles.isdigit():
            options.tiles_x = int(options.tiles)
            options.tiles_y = options.tiles_x
        else:
            match = re.search(r'^(\d+)x(\d+)$', options.tiles)
            if match:
                options.tiles_x = int(match.group(1))
                options.tiles_y = int(match.group(2))
        if not 1 <= options.tiles_x * options.tiles_y <= 144:
            raise Exception('--tiles needs positive integer argument, or two integers separated '
                            'by x; max. number of tiles is 144')

    if options.debug:
        log_level = logging.DEBUG
    else:
        log_level = logging.INFO
    logging.basicConfig(level=log_level, format='%(asctime)s %(message)s', datefmt='%H:%M:%S')
    run(options)