[Boost-commit] svn:boost r75670 - trunk/boost/geometry/algorithms/detail/overlay

Subject: [Boost-commit] svn:boost r75670 - trunk/boost/geometry/algorithms/detail/overlay
From: barend.gehrels_at_[hidden]
Date: 2011-11-26 12:30:17

Author: barendgehrels
Date: 2011-11-26 12:30:16 EST (Sat, 26 Nov 2011)
New Revision: 75670
URL: http://svn.boost.org/trac/boost/changeset/75670

Log:
Linestring/polygon overlay, phase 7 (collinear/equal)
Text files modified: 
   trunk/boost/geometry/algorithms/detail/overlay/follow.hpp |    22 +++++++++++++++++++---                  
   1 files changed, 19 insertions(+), 3 deletions(-)

Modified: trunk/boost/geometry/algorithms/detail/overlay/follow.hpp
==============================================================================
--- trunk/boost/geometry/algorithms/detail/overlay/follow.hpp	(original)
+++ trunk/boost/geometry/algorithms/detail/overlay/follow.hpp	2011-11-26 12:30:16 EST (Sat, 26 Nov 2011)
@@ -16,10 +16,8 @@
 #include <boost/geometry/algorithms/detail/overlay/append_no_duplicates.hpp>
 #include <boost/geometry/algorithms/detail/overlay/copy_segments.hpp>
 #include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>
-#include <boost/geometry/core/access.hpp>
-#include <boost/geometry/core/coordinate_dimension.hpp>
-#include <boost/geometry/geometries/concepts/check.hpp>
 
+#include <boost/geometry/algorithms/within.hpp>
 
 
 namespace boost { namespace geometry
@@ -108,6 +106,18 @@
         return false;
     }
 
+    template <typename Turn>
+    static inline bool was_entered(Turn const& turn, bool first)
+    {
+        if (first && (turn.method == method_collinear || turn.method == method_equal))
+        {
+            // If it is the very first point, and either equal or collinear, there is only one
+            // IP generated (on purpose). So consider this as having entered. 
+            // Maybe it will leave immediately after that (u/i) but that is checked later.
+            return true;
+        }
+        return false;
+    }
 
 public :
     template<typename Turns, typename OutputIterator>
@@ -137,6 +147,12 @@
         {
             turn_operation_iterator_type iit = boost::begin(it->operations);
 
+            if (was_entered(*it, first))
+            {
+                debug_traverse(*it, *iit, "-> Was entered");
+                entered = true;
+            }
+
             if (is_staying_inside(*it, *iit, entered, first, linestring, polygon))
             {
                 debug_traverse(*it, *iit, "-> Staying inside");