From 2d47f24a7e7701c91db1ced34bb3a1b8708b217f Mon Sep 17 00:00:00 2001
From: Dane Springmeyer <dane@dbsgeo.com>
Date: Sun, 25 Jan 2009 19:02:07 +0000
Subject: [PATCH] + added ability to transform Envelopes in addition to Coords
 in new python ProjTransform, closes #117

---
 CHANGELOG                                 |  8 ++++--
 bindings/python/mapnik_proj_transform.cpp | 34 ++++++++++++++++++++---
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index b79d44de5..147f81d37 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -14,8 +14,10 @@ For a complete change history, see the SVN log.
 Current Version (0.6.0-dev, SVN trunk):
 ---------------------------------------
 
-- python/mapnik_map.cpp, map.hpp, and map.cpp: Made available the scale_denominator property from the map in c++ and python (r793)
+- Python: Made available the scale_denominator property from the map in c++ and python (r793)
 
-- python/mapnik_map.cpp: Added ability to resize map and clear all layers and styles from python (r792)
+- Python: Added ability to resize map and clear all layers and styles from python (r793)
 
-- load_map.cpp and save_map.cpp: Added xml serialization for abstract, title, minzoom, maxzoom, and queryable attributes (r787)
\ No newline at end of file
+- Python: Exposed Proj to/from transformation for projected coordinate systems (r792,r821) (#117)
+
+- XML: Added xml serialization for abstract, title, minzoom, maxzoom, and queryable attributes (r787)
\ No newline at end of file
diff --git a/bindings/python/mapnik_proj_transform.cpp b/bindings/python/mapnik_proj_transform.cpp
index 4d891a66f..b1bdb87bf 100644
--- a/bindings/python/mapnik_proj_transform.cpp
+++ b/bindings/python/mapnik_proj_transform.cpp
@@ -28,7 +28,7 @@
 
 namespace  {
 
-   mapnik::coord2d forward_transform(mapnik::proj_transform& t, mapnik::coord2d const& c)
+   mapnik::coord2d forward_transform_c(mapnik::proj_transform& t, mapnik::coord2d const& c)
    {
       double x = c.x;
       double y = c.y;
@@ -37,7 +37,7 @@ namespace  {
       return mapnik::coord2d(x,y);
    }
    
-   mapnik::coord2d backward_transform(mapnik::proj_transform& t, mapnik::coord2d const& c)
+   mapnik::coord2d backward_transform_c(mapnik::proj_transform& t, mapnik::coord2d const& c)
    {
       double x = c.x;
       double y = c.y;
@@ -45,6 +45,30 @@ namespace  {
       t.backward(x,y,z);
       return mapnik::coord2d(x,y);
    }
+
+   mapnik::Envelope<double> forward_transform_env(mapnik::proj_transform& t, mapnik::Envelope<double> const & box)
+   {
+      double minx = box.minx();
+      double miny = box.miny();
+      double maxx = box.maxx();
+      double maxy = box.maxy();
+      double z = 0.0;
+      t.forward(minx,miny,z);
+      t.forward(maxx,maxy,z);
+      return mapnik::Envelope<double>(minx,miny,maxx,maxy);
+   }
+
+   mapnik::Envelope<double> backward_transform_env(mapnik::proj_transform& t, mapnik::Envelope<double> const & box)
+   {
+      double minx = box.minx();
+      double miny = box.miny();
+      double maxx = box.maxx();
+      double maxy = box.maxy();
+      double z = 0.0;
+      t.backward(minx,miny,z);
+      t.backward(maxx,maxy,z);
+      return mapnik::Envelope<double>(minx,miny,maxx,maxy);
+   }   
 }
 
 void export_proj_transform ()
@@ -53,8 +77,10 @@ void export_proj_transform ()
     using mapnik::proj_transform;
     using mapnik::projection;
     class_<proj_transform, boost::noncopyable>("ProjTransform", init< projection const&, projection const& >())
-       .def("forward", forward_transform)
-       .def("backward",backward_transform)
+       .def("forward", forward_transform_c)
+       .def("backward",backward_transform_c)
+       .def("forward", forward_transform_env)
+       .def("backward",backward_transform_env)
        ;
     
 }