X-Git-Url: https://git.openstreetmap.org/rails.git/blobdiff_plain/4f304e23018e9a1380e2374b9a8d419275d99c76..00bd8be546e8daa1f806d7937d5943846066cb8b:/lib/osm.rb

diff --git a/lib/osm.rb b/lib/osm.rb
index 51e98f4ae..b6dd64b99 100644
--- a/lib/osm.rb
+++ b/lib/osm.rb
@@ -371,12 +371,17 @@ module OSM
     end
 
     # and these two will give you the right points on your image. all the constants can be reduced to speed things up. FIXME
+    # If the bbox has no extent, return the centre of the image to avoid dividing by zero.
 
     def y(lat)
+      return @height / 2 if (@by - @ty).zero?
+
       @height - ((ysheet(lat) - @ty) / (@by - @ty) * @height)
     end
 
     def x(lon)
+      return @width / 2 if (@bx - @tx).zero?
+
       ((xsheet(lon) - @tx) / (@bx - @tx) * @width)
     end
   end