+add pickle support for proj_transform and view/coord_transform - see #345

bindings/python/mapnik_proj_transform.cpp

@@ -25,6 +25,19 @@
 #include <mapnik/proj_transform.hpp>
 // boost
 #include <boost/python.hpp>
+ 
+using mapnik::proj_transform;
+using mapnik::projection;
+
+struct proj_transform_pickle_suite : boost::python::pickle_suite
+{
+    static boost::python::tuple
+    getinitargs(const proj_transform& p)
+    {
+        using namespace boost::python;
+        return boost::python::make_tuple(p.source(),p.dest());
+    }
+};
 
 namespace  {
 
@@ -73,10 +86,10 @@ namespace  {
 
 void export_proj_transform ()
 {
-    using namespace boost::python; 
-    using mapnik::proj_transform;
-    using mapnik::projection;
+    using namespace boost::python;
+    
     class_<proj_transform, boost::noncopyable>("ProjTransform", init< projection const&, projection const& >())
+       .def_pickle(proj_transform_pickle_suite())
        .def("forward", forward_transform_c)
        .def("backward",backward_transform_c)
        .def("forward", forward_transform_env)

bindings/python/mapnik_view_transform.cpp

@@ -27,6 +27,18 @@
 // mapnik
 #include <mapnik/ctrans.hpp>
 
+using mapnik::CoordTransform;
+
+struct view_transform_pickle_suite : boost::python::pickle_suite
+{
+    static boost::python::tuple
+    getinitargs(const CoordTransform& c)
+    {
+        using namespace boost::python;
+        return boost::python::make_tuple(c.width(),c.height(),c.extent());
+    }
+};
+
 namespace {
 
    mapnik::coord2d forward_point(mapnik::CoordTransform const& t, mapnik::coord2d const& in)
@@ -58,11 +70,11 @@ void export_view_transform()
 {
    using namespace boost::python;
    using mapnik::Envelope;
-   using mapnik::CoordTransform;
    using mapnik::coord2d;
    
    class_<CoordTransform>("ViewTransform",init<int,int,Envelope<double> const& > (
       "Create a ViewTransform with a width and height as integers and extent"))
+      .def_pickle(view_transform_pickle_suite())
       .def("forward", forward_point)
       .def("backward",backward_point)
       .def("forward", forward_envelope)

include/mapnik/ctrans.hpp

@@ -124,8 +124,8 @@ namespace mapnik {
    class CoordTransform
    {
       private:
-         int width;
-         int height;
+         int width_;
+         int height_;
          double sx_;
          double sy_;
          Envelope<double> extent_;
@@ -134,12 +134,22 @@ namespace mapnik {
       public:
          CoordTransform(int width,int height,const Envelope<double>& extent,
                         double offset_x = 0, double offset_y = 0)
-            :width(width),height(height),extent_(extent),offset_x_(offset_x),offset_y_(offset_y)
+            :width_(width),height_(height),extent_(extent),offset_x_(offset_x),offset_y_(offset_y)
          {
-            sx_ = ((double)width)/extent_.width();
-            sy_ = ((double)height)/extent_.height();
+            sx_ = ((double)width_)/extent_.width();
+            sy_ = ((double)height_)/extent_.height();
          }
-	
+
+         inline int width() const
+         {
+            return width_;
+         }
+      
+         inline int height() const
+         {
+            return height_;
+         }
+         	
          inline double scale_x() const
          {
             return sx_;

include/mapnik/proj_transform.hpp

@@ -40,6 +40,8 @@ namespace mapnik {
         
         bool forward (double& x, double& y , double& z) const;
         bool backward (double& x, double& y , double& z) const;
+        mapnik::projection const& source() const;
+        mapnik::projection const& dest() const;
         
     private:
         projection const& source_;

src/proj_transform.cpp

@@ -99,5 +99,15 @@ namespace mapnik {
         }
         
         return true;
-    } 
+    }
+
+    mapnik::projection const& proj_transform::source() const
+    {
+        return source_;
+    }
+    mapnik::projection const& proj_transform::dest() const
+    {
+        return dest_;
+    }
+ 
 }