Denis Laprise web log

import sys, urllib2, re,os, Image, httplib
 
def parselink(link):
 qs = link[link.index('?')+1:]
 vals = [v.split('=') for v in qs.split('&')]
 params = {}
 for v in vals:
  params[v[0]] = v[1]
 zoom = int(params['z'] or '0')
 center = map(float, params['ll'].split(','))
 span = map(float, params['spn'].split(','))
 ne, sw = list(center), list(center)
 ne[0] += span[0]
 ne[1] += span[1]
 sw[0] -= span[0]
 sw[1] -= span[1]
 return ne, sw, zoom
 
def fetch(pt):
 if pt.zoom > Core.Coordinate.MAX_ZOOM:
  return
 
 if download(pt):
  z = pt.zoomBy(1)
  fetch(z)
  fetch(z.right())
  fetch(z.down())
  fetch(z.down().right())
 
def download(pt):
  url = layer.getTileUrls(pt)[0]
  try:
   os.makedirs("tiles/%d/%d" % (pt.zoom, pt.row))
  except: pass
  fn = "tiles/%d/%d/%d_%d.jpg" % (pt.zoom, pt.row, pt.row, pt.column)
  if os.path.exists(fn):
   try:
    m = Image.open(fn)
    a,b,c,d = m.getbbox()
    return d > 1
   except:
    return False
  print url
  try:
   # should use urllib2 to fake user agent here
   data = urllib.urlopen(url).read()
   out = open(fn, 'w')
   out.write(data)
   out.close()
   return True
  except urllib2.HTTPError, e:
   if e.code == 404:
    #empty tile
    out = Image.new('RGB', (1,1))
    out.save(fn)
    return False
 
  #should not reach this point. add better error handling
  sys.exit(-1)
 
if __name__ == "__main__":
 sys.path.append('trunk/py/')
 from ModestMaps import *
 
 layer = Google.AerialProvider()
 bbox = parselink('http://maps.google.com/maps?f=q&hl=en&geocode=&q=new++york,+ny&ie=UTF8&ll=40.75506,-73.969917&spn=0.100907,0.197926&t=h&z=13&iwloc=addr')
 ne = layer.locationCoordinate(Geo.Location(bbox[0][0], bbox[0][1])).zoomTo(bbox[-1]).container()
 sw = layer.locationCoordinate(Geo.Location(bbox[1][0], bbox[1][1])).zoomTo(bbox[-1]).container()
 cur = ne.copy()
 while cur.row <= sw.row:
   while cur.column >= sw.column:
    fetch(cur.copy())
    cur = cur.left()
   cur.column = ne.column
   cur = cur.down()