Initial Commit

1 files changed, 124 insertions, 0 deletions

diff --git a/googlemaps.py b/googlemaps.py
new file mode 100644
index 0000000..0998cfd
--- /dev/null
+++ b/googlemaps.py
@@ -0,0 +1,124 @@
+MIN_SATELLITE_ZOOM = -5
+MIN_MAP_ZOOM = 0
+MIN_OVERLAY_ZOOM = 0
+MIN_RELIEF_ZOOM = 2
+
+def fetch(url):
+	import os
+	img = os.popen('curl -s -f "%(url)s"' % vars(), 'r').read()
+	if len(img):
+		return img
+	return None
+
+def image_number_to_sel(x, y, zoom, sel_t = ['q','r','t','s']):
+	x = int(x)
+	y = int(y)
+	bits = range(17-zoom); bits.reverse()
+	sel = 't'
+	for bit in bits:
+		index = 0
+		if x & (1<<bit):
+			index |= 1
+		if y & (1<<bit):
+			index |= 2
+		sel += sel_t[index]
+	return sel
+
+def fetch_satellite_img(x, y, zoom):
+	if zoom < MIN_SATELLITE_ZOOM:
+		return None
+	x = int(x)
+	y = int(y)
+	num = (x+y)%4
+	sel = image_number_to_sel(x, y, zoom)
+	url = "http://kh%(num)d.google.com/kh?n=404&v&t=%(sel)s" % vars()
+	return fetch(url)
+
+def fetch_map_img(x, y, zoom):
+	if zoom < MIN_MAP_ZOOM:
+		return None
+	x = int(x)
+	y = int(y)
+	num = (x+y)%4
+	mapmode = "w2.75"
+	url = "http://mt%(num)d.google.com/mt?n=404&v=%(mapmode)s&zoom=%(zoom)d&x=%(x)d&y=%(y)d" % vars()
+	return fetch(url)
+
+def fetch_relief_img(x, y, zoom):
+	if zoom < MIN_RELIEF_ZOOM:
+		return None
+	x = int(x)
+	y = int(y)
+	num = (x+y)%4
+	mapmode = "w2p.71"
+	url = "http://mt%(num)d.google.com/mt?n=404&v=%(mapmode)s&zoom=%(zoom)d&x=%(x)d&y=%(y)d" % vars()
+	return fetch(url)
+
+def fetch_overlay_img(x, y, zoom):
+	if zoom < MIN_OVERLAY_ZOOM:
+		return None
+	x = int(x)
+	y = int(y)
+	num = (x+y)%4
+	mapmode = "w2t.75"
+	url = "http://mt%(num)d.google.com/mt?n&v=%(mapmode)s&zoom=%(zoom)d&x=%(x)d&y=%(y)d" % vars()
+	return fetch(url)
+
+def get_image_number(lon, lat, zoom):
+	import math
+	from math import pi
+
+	def deg2rad(a):
+		return a * pi/180.
+
+	def frac(x):
+		return x - math.floor(x)
+
+	def h(lat):
+		lat = deg2rad(lat)
+		# value determined by fitting original google maps
+		# output to mercator map formula
+		a = 0.0795775
+		# mercator projection formula
+		return a * math.log((1. + math.sin(lat)) / (1. - math.sin(lat)))
+
+	t = (2**(17-zoom))
+	off = (2**(16-zoom))
+
+	lat = h(-lat)
+	lon = (lon / 360.)
+
+	x = lon * t + off
+	y = lat * t + off
+
+	xx = int(x)
+	yy = int(y)
+
+	px = frac(x) * 256
+	py = frac(y) * 256
+
+	return (xx, yy, x, y, px, py)
+
+def get_satellite(lon, lat, zoom):
+	if zoom < MIN_SATELLITE_ZOOM:
+		return None
+	img_num = get_image_number(lon, lat, zoom)
+	return fetch_satellite_img(img_num[0], img_num[1], zoom)
+
+def get_map(lon, lat, zoom):
+	if zoom < MIN_MAP_ZOOM:
+		return None
+	img_num = get_image_number(lon, lat, zoom)
+	return fetch_map_img(img_num[0], img_num[1], zoom)
+
+def get_relief(lon, lat, zoom):
+	if zoom < MIN_RELIEF_ZOOM:
+		return None
+	img_num = get_image_number(lon, lat, zoom)
+	return fetch_relief_img(img_num[0], img_num[1], zoom)
+
+def get_overlay(lon, lat, zoom):
+	if zoom < MIN_OVERLAY_ZOOM:
+		return None
+	img_num = get_image_number(lon, lat, zoom)
+	return fetch_overlay_img(img_num[0], img_num[1], zoom)