--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/regions.py Wed Jul 29 23:45:53 2020 +0300
@@ -0,0 +1,88 @@
+#!/usr/bin/env python3
+from xml.etree import ElementTree
+from geometry import *
+
+REGION_TYPES = ['major', 'minor']
+REGION_KEY_VALUES = [x + '_region' for x in REGION_TYPES]
+SHAPE_KEYS = [x + '_shapes' for x in REGION_TYPES]
+
+def parse_nodes(root):
+ nodes = {}
+ for child in root:
+ if child.tag == 'node':
+ lat, lon = float(child.attrib['lat']), float(child.attrib['lon'])
+ nodes[child.attrib['id']] = Location(lat, lon)
+ return nodes
+
+def parse_way(way, nodes):
+ def choose_shapes(way, boundary):
+ return (way['major_shapes']
+ if boundary == 'major_region'
+ else way['minor_shapes'])
+ result = {'minor_shapes': [], 'major_shapes': []}
+ shape = []
+ for child in way:
+ if child.tag == 'nd':
+ shape.append(child.attrib['ref'])
+ elif child.tag == 'tag':
+ key = child.attrib['k']
+ if key in SHAPE_KEYS:
+ raise ValueError(str.format('tag "{}" is not allowed', key))
+ result[key] = child.attrib['v']
+ if key == 'boundary' and result['boundary'] not in REGION_KEY_VALUES:
+ return None # we're not interested in it!
+ if shape[-1] != shape[0]:
+ raise ValueError('polygon is not closed: %r' % result)
+ if 'boundary' not in result:
+ raise ValueError('polygon not tagged as a boundary: %r' % result)
+ shape = [nodes[ref] for ref in shape[:-1]]
+ choose_shapes(result, result['boundary']).append(Polygon(*shape))
+ return result
+
+def parse_boundaries(root, *, nodes):
+ for child in root:
+ if child.tag == 'way':
+ way = parse_way(child, nodes = nodes)
+ if way:
+ yield way
+
+def parse_regions(filename):
+ from katakana import transliterate as transliterate_katakana
+ tree = ElementTree.parse(filename)
+ root = tree.getroot()
+ nodes = parse_nodes(root)
+ regions = dict()
+ extra_shapes = list()
+ for way in parse_boundaries(root, nodes = nodes):
+ if 'boundary' in way and way['boundary'] != 'subregion' and 'name' in way:
+ # defines a region
+ way['via_factor'] = int(way.get('via_factor', 1))
+ if way['name'] in regions:
+ raise ValueError(str.format(
+ 'Region {name} defined twice',
+ name = repr(way['name']),
+ ))
+ regions[way['name']] = way
+ del way['boundary']
+ if 'external' in way:
+ way['boundary'] = 'minor_region'
+ for prefix in ['', 'short_', 'internal_']:
+ name_key = prefix + 'name'
+ if name_key in way and way[name_key] and name_key + ':ja' not in way:
+ way[name_key + ':ja'] = transliterate_katakana(way[name_key])
+ elif 'boundary' in way and 'is_in' in way:
+ # adds an extra shape to an existing region
+ extra_shapes.append(way)
+ for extra_shape in extra_shapes:
+ name = extra_shape['is_in']
+ try:
+ region = regions[name]
+ except KeyError:
+ raise ValueError(str.format(
+ 'Extra shape refers to {name} which was not found: {extra_shape}',
+ name = repr(name),
+ extra_shape = repr(extra_shape),
+ ))
+ for key in SHAPE_KEYS:
+ region[key].extend(extra_shape[key])
+ return regions