+ WKT generator for mapnik::geometry_container

bindings/python/mapnik_geometry.cpp

@@ -117,6 +117,24 @@ std::string to_wkt( geometry_type const& geom)
 #endif
 }
 
+std::string to_wkt2( path_type const& geom)
+{
+#if BOOST_VERSION >= 104700
+    std::string wkt; // Use Python String directly ?
+    bool result = mapnik::util::to_wkt(wkt,geom);
+    if (!result) 
+    {
+        throw std::runtime_error("Generate WKT failed");
+    }
+    return wkt;
+#else
+    std::ostringstream s;
+    s << BOOST_VERSION/100000 << "." << BOOST_VERSION/100 % 1000  << "." << BOOST_VERSION % 100;
+    throw std::runtime_error("mapnik::to_wkt() requires at least boost 1.47 while your build was compiled against boost " + s.str());
+#endif
+}
+
+
 void export_geometry()
 {
     using namespace boost::python;
@@ -142,6 +160,7 @@ void export_geometry()
         .def("__len__", &path_type::size)
         .def("add_wkt",add_wkt_impl)
         .def("add_wkb",add_wkb_impl)
+        .def("to_wkt",&to_wkt2)
         .def("from_wkt",from_wkt_impl)
         .def("from_wkb",from_wkb_impl)
         .staticmethod("from_wkt")

include/mapnik/util/geometry_to_wkt.hpp

@@ -42,7 +42,16 @@ bool to_wkt(std::string & wkt, mapnik::geometry_type const& geom)
 {
     typedef std::back_insert_iterator<std::string> sink_type;
     sink_type sink(wkt);
-    wkt_generator<sink_type> generator;
+    wkt_generator<sink_type> generator(true);
+    bool result = karma::generate(sink, generator, geom);
+    return result;
+}
+
+bool to_wkt(std::string & wkt, mapnik::geometry_container const& geom)
+{
+    typedef std::back_insert_iterator<std::string> sink_type;
+    sink_type sink(wkt);
+    wkt_multi_generator<sink_type> generator;
     bool result = karma::generate(sink, generator, geom);
     return result;
 }

include/mapnik/util/geometry_wkt_generator.hpp

@@ -30,7 +30,6 @@
 #include <mapnik/geometry.hpp>
 #include <mapnik/util/vertex_iterator.hpp>
 #include <mapnik/util/container_adapter.hpp>
-
 // boost
 #include <boost/tuple/tuple.hpp>
 #include <boost/spirit/include/karma.hpp>
@@ -49,6 +48,8 @@ namespace mapnik { namespace util {
 namespace karma = boost::spirit::karma;
 namespace phoenix = boost::phoenix;
 
+namespace {
+
 struct get_type
 {
     template <typename T>
@@ -73,21 +74,52 @@ struct get_first
     }
 };
 
+
+struct multi_geometry_
+{
+    template <typename T>
+    struct result { typedef bool type; };
+    
+    bool operator() (geometry_container const& geom) const
+    {
+        return geom.size() > 1 ? true : false;
+    }
+};
+
+struct multi_geometry_type
+{
+    template <typename T>
+    struct result { typedef unsigned type; };
+    
+    unsigned operator() (geometry_container const& geom) const
+    {
+        unsigned type = 0u;
+        geometry_container::const_iterator itr = geom.begin();
+        geometry_container::const_iterator end = geom.end();
+        for ( ; itr != end; ++itr)
+        {
+            type = itr->type();
+        }
+        return  type;
+    }
+};
+
 template <typename T>
 struct coordinate_policy : karma::real_policies<T>
 {
     typedef boost::spirit::karma::real_policies<T> base_type;
     static int floatfield(T n) { return base_type::fmtflags::fixed; }
-    static unsigned precision(T n) { return 6u ;}
+    static unsigned precision(T n) { return 6 ;}
 };
 
+}
 
 template <typename OutputIterator>
 struct wkt_generator : 
         karma::grammar<OutputIterator, geometry_type const& ()>
 {
     
-    wkt_generator()
+    wkt_generator(bool single = false)
         : wkt_generator::base_type(wkt)
     {
         using boost::spirit::karma::uint_;
@@ -97,22 +129,27 @@ struct wkt_generator :
         using boost::spirit::karma::_a;
         using boost::spirit::karma::_r1;
         using boost::spirit::karma::eps;
+        using boost::spirit::karma::string;
         
         wkt = point | linestring | polygon 
             ;
         
         point = &uint_(mapnik::Point)[_1 = _type(_val)] 
-            << lit("Point(") << point_coord [_1 = _first(_val)] << lit(')')
+            << string[ phoenix::if_ (single) [_1 = "Point("] 
+                       .else_[_1 = "("]] 
+            << point_coord [_1 = _first(_val)] << lit(')')
             ;
         
         linestring = &uint_(mapnik::LineString)[_1 = _type(_val)] 
-            << lit("LineString(") 
+            << string[ phoenix::if_ (single) [_1 = "LineString("] 
+                       .else_[_1 = "("]] 
             << coords 
             << lit(')')
             ;
         
         polygon = &uint_(mapnik::Polygon)[_1 = _type(_val)]
-            << lit("Polygon(")
+            << string[ phoenix::if_ (single) [_1 = "Polygon("] 
+                       .else_[_1 = "("]] 
             << coords2
             << lit("))")            
             ;
@@ -121,8 +158,8 @@ struct wkt_generator :
             ;
         
         polygon_coord %= ( &uint_(mapnik::SEG_MOVETO) << eps[_r1 += 1] 
-                   << karma::string[ if_ (_r1 > 1) [_1 = "),("]
+                   << string[ if_ (_r1 > 1) [_1 = "),("]
-                                     .else_[_1 = "("] ] | &uint_ << ",") 
+                              .else_[_1 = "("] ] | &uint_ << ",") 
             << coord_type 
             << lit(' ') 
             << coord_type
@@ -144,7 +181,7 @@ struct wkt_generator :
     karma::rule<OutputIterator, geometry_type const& ()> coords;
     karma::rule<OutputIterator, karma::locals<unsigned>, geometry_type const& ()> coords2;
     karma::rule<OutputIterator, geometry_type::value_type ()> point_coord;
-    karma::rule<OutputIterator, geometry_type::value_type const& (unsigned& )> polygon_coord;
+    karma::rule<OutputIterator, geometry_type::value_type (unsigned& )> polygon_coord;
     
     // phoenix functions
     phoenix::function<get_type > _type;
@@ -154,6 +191,50 @@ struct wkt_generator :
     
 };
 
+
+template <typename OutputIterator>
+struct wkt_multi_generator : 
+        karma::grammar<OutputIterator, geometry_container const& ()>
+{
+    
+    wkt_multi_generator()
+        : wkt_multi_generator::base_type(wkt)
+    {
+        using boost::spirit::karma::lit;
+        using boost::spirit::karma::eps;
+        using boost::spirit::karma::_val;
+        using boost::spirit::karma::_1;
+        
+        geometry_types.add
+            (mapnik::Point,"Point")
+            (mapnik::LineString,"LineString")
+            (mapnik::Polygon,"Polygon")
+            ;
+        
+        wkt =  eps(_multi(_val)) << "Multi" << geometry_types[_1 = _type(_val)] 
+                                 << "(" << multi_geometry << ")" | geometry_types[_1 = _type(_val)] 
+                                 << geometry
+            ;
+
+        geometry = *path  
+            ; 
+        
+        multi_geometry = -(path % lit(',')) 
+            ; 
+        
+    }
+    // rules
+    karma::rule<OutputIterator, geometry_container const& ()> wkt;
+    karma::rule<OutputIterator, geometry_container const& ()> geometry;
+    karma::rule<OutputIterator, geometry_container const& ()> multi_geometry;
+    wkt_generator<OutputIterator>  path;
+    // phoenix
+    phoenix::function<multi_geometry_> _multi;
+    phoenix::function<multi_geometry_type> _type;
+    //
+    karma::symbols<unsigned, char const*> geometry_types;
+};
+
 }}