CalculateBoundsZoomLevel関数を提供する古いGoogle Maps APIブログにリンクされたPythonリファレンスが見つかりました。
ソースファイルはhereです。
def CalculateBoundsZoomLevel(self, bounds, view_size):
"""Given lat/lng bounds, returns map zoom level.
This method is used to take in a bounding box (southwest and northeast
bounds of the map view we want) and a map size and it will return us a zoom
level for our map. We use this because if we take the bottom left and
upper right on the map we want to show, and calculate what pixels they
would be on the map for a given zoom level, then we can see how many pixels
it will take to display the map at this zoom level. If our map size is
within this many pixels, then we have the right zoom level.
Args:
bounds: A list of length 2, each holding a list of length 2. It holds
the southwest and northeast lat/lng bounds of a map. It should look
like this: [[southwestLat, southwestLat], [northeastLat, northeastLng]]
view_size: A list containing the width/height in pixels of the map.
Returns:
An int zoom level.
"""
zmax = 18
zmin = 0
bottom_left = bounds[0]
top_right = bounds[1]
backwards_range = range(zmin, zmax)
backwards_range.reverse()
for z in backwards_range:
bottom_left_pixel = self.FromLatLngToPixel(bottom_left, z)
top_right_pixel = self.FromLatLngToPixel(top_right, z)
if bottom_left_pixel.x > top_right_pixel.x :
bottom_left_pixel.x -= self.CalcWrapWidth(z)
if abs(top_right_pixel.x - bottom_left_pixel.x) <= view_size[0] \
and abs(top_right_pixel.y - bottom_left_pixel.y) <= view_size[1] :
return z
return 0