Refactor calculation of zoom level based on a scale

[rails.git] / app / helpers / application_helper.rb

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index ce0c5d67bb68d37945d0d42213e92d3ef1f08373..4aec9f5c16811e79f14f68d9133ea9e30341d2a3 100644 (file)
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -125,6 +125,10 @@ module ApplicationHelper
     end
   end
 
+  def scale_to_zoom(scale)
+    Math.log(360.0 / (scale.to_f * 512.0)) / Math.log(2.0)
+  end
+
 private
 
   def javascript_strings_for_key(key)