Subject: [Boost-commit] svn:boost r86305 - trunk/boost/geometry/algorithms
From: bruno.lalande_at_[hidden]
Date: 2013-10-14 16:04:55
Author: bruno.lalande
Date: 2013-10-14 16:04:54 EDT (Mon, 14 Oct 2013)
New Revision: 86305
URL: http://svn.boost.org/trac/boost/changeset/86305
Log:
Made centroid variant-aware. This implied a refactoring - we're clearly heading towards a multi-stage algorithm call resolution as previously foreseen. Will align other variant-aware algorithms to this.
Text files modified:
trunk/boost/geometry/algorithms/centroid.hpp | 136 ++++++++++++++++++++++++++++++---------
1 files changed, 103 insertions(+), 33 deletions(-)
Modified: trunk/boost/geometry/algorithms/centroid.hpp
==============================================================================
--- trunk/boost/geometry/algorithms/centroid.hpp Mon Oct 14 15:50:13 2013 (r86304)
+++ trunk/boost/geometry/algorithms/centroid.hpp 2013-10-14 16:04:54 EDT (Mon, 14 Oct 2013) (r86305)
@@ -19,6 +19,9 @@
#include <boost/range.hpp>
#include <boost/typeof/typeof.hpp>
+#include <boost/variant/static_visitor.hpp>
+#include <boost/variant/apply_visitor.hpp>
+#include <boost/variant/variant_fwd.hpp>
#include <boost/geometry/core/closure.hpp>
#include <boost/geometry/core/cs.hpp>
@@ -34,6 +37,7 @@
#include <boost/geometry/geometries/concepts/check.hpp>
#include <boost/geometry/strategies/centroid.hpp>
#include <boost/geometry/strategies/concepts/centroid_concept.hpp>
+#include <boost/geometry/strategies/default_strategy.hpp>
#include <boost/geometry/views/closeable_view.hpp>
#include <boost/geometry/util/for_each_coordinate.hpp>
@@ -307,6 +311,103 @@
#endif // DOXYGEN_NO_DISPATCH
+namespace resolve_strategy {
+
+template <typename Geometry>
+struct centroid
+{
+ template <typename Point, typename Strategy>
+ static inline void apply(Geometry const& geometry, Point& out, Strategy const& strategy)
+ {
+ dispatch::centroid<Geometry>::apply(geometry, out, strategy);
+ }
+
+ template <typename Point>
+ static inline void apply(Geometry const& geometry, Point& out, default_strategy)
+ {
+ typedef typename strategy::centroid::services::default_strategy
+ <
+ typename cs_tag<Geometry>::type,
+ typename tag_cast
+ <
+ typename tag<Geometry>::type,
+ pointlike_tag,
+ linear_tag,
+ areal_tag
+ >::type,
+ dimension<Geometry>::type::value,
+ Point,
+ Geometry
+ >::type strategy_type;
+
+ dispatch::centroid<Geometry>::apply(geometry, out, strategy_type());
+ }
+};
+
+} // namespace resolve_strategy
+
+
+namespace check_input {
+
+template <typename Geometry>
+struct centroid
+{
+ template <typename Point, typename Strategy>
+ static inline void apply(Geometry const& geometry, Point& out, Strategy const& strategy)
+ {
+ concept::check_concepts_and_equal_dimensions<Point, Geometry const>();
+ resolve_strategy::centroid<Geometry>::apply(geometry, out, strategy);
+ }
+};
+
+} // namespace check_input
+
+
+namespace resolve_variant {
+
+template <typename Geometry>
+struct centroid
+{
+ template <typename Point, typename Strategy>
+ static inline void apply(Geometry const& geometry, Point& out, Strategy const& strategy)
+ {
+ check_input::centroid<Geometry>::apply(geometry, out, strategy);
+ }
+};
+
+template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
+struct centroid<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> >
+{
+ template <typename Point, typename Strategy>
+ struct visitor: boost::static_visitor<void>
+ {
+ Point& m_out;
+ Strategy const& m_strategy;
+
+ visitor(Point& out, Strategy const& strategy)
+ : m_out(out), m_strategy(strategy)
+ {}
+
+ template <typename Geometry>
+ void operator()(Geometry const& geometry) const
+ {
+ return check_input::centroid<Geometry>::apply(geometry, m_out, m_strategy);
+ }
+ };
+
+ template <typename Point, typename Strategy>
+ static inline void
+ apply(boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)> const& geometry,
+ Point& out,
+ Strategy const& strategy)
+ {
+ return boost::apply_visitor(visitor<Point, Strategy>(out, strategy), geometry);
+ }
+};
+
+};
+
+
/*!
\brief \brief_calc{centroid} \brief_strategy
\ingroup centroid
@@ -328,15 +429,7 @@
inline void centroid(Geometry const& geometry, Point& c,
Strategy const& strategy)
{
- //BOOST_CONCEPT_ASSERT( (geometry::concept::CentroidStrategy<Strategy>) );
-
- concept::check_concepts_and_equal_dimensions<Point, Geometry const>();
-
- typedef typename point_type<Geometry>::type point_type;
-
- // Call dispatch apply method. That one returns true if centroid
- // should be taken from state.
- dispatch::centroid<Geometry>::apply(geometry, c, strategy);
+ resolve_variant::centroid<Geometry>::apply(geometry, c, strategy);
}
@@ -359,24 +452,7 @@
template<typename Geometry, typename Point>
inline void centroid(Geometry const& geometry, Point& c)
{
- concept::check_concepts_and_equal_dimensions<Point, Geometry const>();
-
- typedef typename strategy::centroid::services::default_strategy
- <
- typename cs_tag<Geometry>::type,
- typename tag_cast
- <
- typename tag<Geometry>::type,
- pointlike_tag,
- linear_tag,
- areal_tag
- >::type,
- dimension<Geometry>::type::value,
- Point,
- Geometry
- >::type strategy_type;
-
- centroid(geometry, c, strategy_type());
+ centroid(geometry, c, default_strategy());
}
@@ -394,8 +470,6 @@
template<typename Point, typename Geometry>
inline Point return_centroid(Geometry const& geometry)
{
- concept::check_concepts_and_equal_dimensions<Point, Geometry const>();
-
Point c;
centroid(geometry, c);
return c;
@@ -419,10 +493,6 @@
template<typename Point, typename Geometry, typename Strategy>
inline Point return_centroid(Geometry const& geometry, Strategy const& strategy)
{
- //BOOST_CONCEPT_ASSERT( (geometry::concept::CentroidStrategy<Strategy>) );
-
- concept::check_concepts_and_equal_dimensions<Point, Geometry const>();
-
Point c;
centroid(geometry, c, strategy);
return c;