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- Committer: Gabriel Patiño
- Date: 2013-06-14 12:50:29 UTC
- Revision ID: gepatino@gmail.com-20130614125029-530i095xxlcsyxom
Initial commmit
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removed
mapper/providers.py
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from math import *
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import Image
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import ImageDraw
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import os.path
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import StringIO
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import urllib2
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import cache
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def numTiles(z):
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return pow(2, z)
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def sec(x):
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return 1 / cos(x)
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def latlon2relativeXY(lat, lon):
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x = (lon + 180.0) / 360.0
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y = (1 - log(tan(radians(lat)) + sec(radians(lat))) / pi) / 2
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return (x, y)
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def latlon2xy(lat, lon, z):
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n = numTiles(z)
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x, y = latlon2relativeXY(lat, lon)
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return (n * x, n * y)
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def tileXY(lat, lon, z):
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x, y = latlon2xy(lat, lon, z)
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return (int(x), int(y))
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def xy2latlon(x, y, z):
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n = numTiles(z)
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relY = y / n
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lat = mercatorToLat(pi * (1 - 2 * relY))
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lon = -180.0 + 360.0 * x / n
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return (lat, lon)
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def latEdges(y, z):
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n = numTiles(z)
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unit = 1 / n
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relY1 = y * unit
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relY2 = relY1 + unit
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lat1 = mercatorToLat(pi * (1 - 2 * relY1))
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lat2 = mercatorToLat(pi * (1 - 2 * relY2))
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return (lat1, lat2)
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def lonEdges(x, z):
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n = numTiles(z)
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unit = 360 / n
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lon1 = -180 + x * unit
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lon2 = lon1 + unit
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return (lon1, lon2)
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def tileEdges(x, y, z):
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north, south = latEdges(y, z)
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west, east = lonEdges(x, z)
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return (south, west, north, east)
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def mercatorToLat(mercatorY):
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return degrees(atan(sinh(mercatorY)))
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class TileProvider(object):
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def __init__(self):
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self.name = 'default'
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self.tile_size = 256
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self.max_zoom = 18
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self.url = '%d/%d/%d'
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def get_tile_url(self, x, y, z):
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return self.url % (z, x, y)
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def compose_map(self, limits, size):
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north, south, east, west = limits
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(crop_n, crop_w, crop_s, crop_e, zoom) = self.surrounding_area(north, west, south, east, size)
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(x1, y1) = tileXY(crop_n, crop_w, zoom)
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(x2, y2) = tileXY(crop_s, crop_e, zoom)
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map_width = ((x2 - x1) + 1) * self.tile_size
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map_height = ((y2 - y1) + 1) * self.tile_size
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(_, w_limit, n_limit, _) = tileEdges(x1, y1, zoom)
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(s_limit, _, _, e_limit) = tileEdges(x2, y2, zoom)
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lat_degs = n_limit - s_limit
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lon_degs = e_limit - w_limit
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lat_deg_size = map_height / lat_degs
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lon_deg_size = map_width / lon_degs
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crop_top = int(ceil((n_limit - crop_n) * lat_deg_size))
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crop_bottom = int(floor((n_limit - crop_s) * lat_deg_size))
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crop_left = int(floor((crop_w - w_limit) * lon_deg_size))
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crop_right = int(ceil((crop_e - w_limit) * lon_deg_size))
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path = os.path.join('tiles', self.name)
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c = cache.DiskCache(path)
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map_img = Image.new('RGBA', (map_width, map_height))
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for i in range(x1, x2 + 1):
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for j in range(y1, y2 + 1):
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url = self.get_tile_url(i, j, zoom)
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data = c[url]
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if data is None:
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print 'Fetching %s ' % url,
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res = urllib2.urlopen(url)
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data = res.read()
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c[url] = data
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print 'DONE'
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datastream = StringIO.StringIO(data)
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im = Image.open(datastream)
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xpos = self.tile_size * (i - x1)
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ypos = self.tile_size * (j - y1)
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map_img.paste(im, (xpos, ypos))
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map_img = map_img.crop((crop_left, crop_top, crop_right, crop_bottom))
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map_img = map_img.resize(size, Image.ANTIALIAS)
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return (map_img, (crop_n, crop_s, crop_e, crop_w))
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def best_zoom(self, north, west, south, east, map_size):
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(relx1, rely1) = latlon2relativeXY(north, west)
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(relx2, rely2) = latlon2relativeXY(south, east)
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rel_width = relx2 - relx1
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rel_height = rely2 - rely1
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z = self.max_zoom
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for z in range(self.max_zoom + 1):
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zoom_pixels = self.tile_size * numTiles(z)
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zoom_width = zoom_pixels * rel_width
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zoom_height = zoom_pixels * rel_height
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if zoom_width >= map_size[0] and zoom_height >= map_size[1]:
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break
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return z
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def surrounding_area(self, north, west, south, east, size):
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aspect_ratio = float(size[0]) / float(size[1])
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(n, w, s, e) = (north, west, south, east)
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finish = False
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while not finish:
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zoom = self.best_zoom(n, w, s, e, size)
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(x1, y1) = latlon2xy(n, w, zoom)
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(x2, y2) = latlon2xy(s, e, zoom)
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map_width = (x2 - x1)
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map_height = (y2 - y1)
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if aspect_ratio >= 1:
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# landscape, keep height
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new_height = map_height
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new_width = map_height * aspect_ratio
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else:
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# portrait, keep width
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new_width = map_width
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new_height = new_width / aspect_ratio
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new_w_delta = new_width - map_width
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new_h_delta = new_height - map_height
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new_x1 = x1 - (new_w_delta / 2)
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new_x2 = x2 + (new_w_delta / 2)
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new_y1 = y1 - (new_h_delta / 2)
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new_y2 = y2 + (new_h_delta / 2)
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(new_n, new_w) = xy2latlon(new_x1, new_y1, zoom)
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(new_s, new_e) = xy2latlon(new_x2, new_y2, zoom)
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new_zoom = self.best_zoom(new_n, new_w, new_s, new_e, size)
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if new_zoom == zoom:
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finish = True
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else:
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(n, w, s, e) = (new_n, new_w, new_s, new_e)
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return (new_n, new_w, new_s, new_e, new_zoom)
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class OpenStreetMapProvider(TileProvider):
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def __init__(self):
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super(OpenStreetMapProvider, self).__init__()
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self.name = 'openstreetmap'
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self.url = 'http://tile.openstreetmap.org/%d/%d/%d.png'
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class OpenCycleMapProvider(TileProvider):
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def __init__(self):
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super(OpenCycleMapProvider, self).__init__()
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self.name = 'opencyclemap'
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self.url = 'http://tile.opencyclemap.org/cycle/%d/%d/%d.png'
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class TransportProvider(TileProvider):
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def __init__(self):
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super(TransportProvider, self).__init__()
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self.name = 'transport'
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self.url = 'http://tile2.opencyclemap.org/transport/%d/%d/%d.png'
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class LandscapeProvider(TileProvider):
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def __init__(self):
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super(LandscapeProvider, self).__init__()
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self.name = 'landscape'
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self.url = 'http://tile3.opencyclemap.org/landscape/%d/%d/%d.png'
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class OutdoorsProvider(TileProvider):
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def __init__(self):
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super(OutdoorsProvider, self).__init__()
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self.name = 'outdoors'
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self.url = 'http://tile.thunderforest.com/outdoors/%d/%d/%d.png'
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PROVIDERS = {
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'openstreetmap': OpenStreetMapProvider,
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'opencyclemap': OpenCycleMapProvider,
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'transport': TransportProvider,
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'landscape': LandscapeProvider,
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'outdoors': OutdoorsProvider,
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}
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def get_provider(pname):
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return PROVIDERS[pname]()
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