Made Scale Denominator available as a property of the Map

bindings/python/mapnik_map.cpp

@@ -326,7 +326,14 @@ void export_map()
                     ">>> m.layers[0]\n"
                     "<mapnik._mapnik.Layer object at 0x5fe130>\n"
          )
-        
+
+      .add_property("scale_denominator", &Map::scale_denominator,
+                    "Return the Map Scale Denominator.\n"
+                    "Usage:\n"
+                    "\n"
+                    ">>> m.scale_denominator\n"
+         )
+
       .add_property("srs",
                     make_function(&Map::srs,return_value_policy<copy_const_reference>()),
                     &Map::set_srs,

include/mapnik/map.hpp

@@ -287,6 +287,8 @@ namespace mapnik
         const Envelope<double>& getCurrentExtent() const;
 
         double scale() const;
+        
+        double scale_denominator() const;
 
         CoordTransform view_transform() const;
 

src/map.cpp

@@ -28,6 +28,7 @@
 #include <mapnik/projection.hpp>
 #include <mapnik/filter_featureset.hpp>
 #include <mapnik/hit_test_filter.hpp>
+#include <mapnik/scale_denominator.hpp>
 
 namespace mapnik
 {
@@ -386,6 +387,12 @@ namespace mapnik
         return currentExtent_.width();
     }
 
+    double Map::scale_denominator() const 
+    {
+        projection map_proj(srs_);
+        return mapnik::scale_denominator( *this, map_proj.is_geographic());    
+    }
+
     CoordTransform Map::view_transform() const
     {
         return CoordTransform(width_,height_,currentExtent_);