Fix contiguous_vertices(). Use it in boundary iterator.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/contiguous_vertices@838 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: 5b4475f39fe6adf2190223a753625057260e8805

1 files changed, 15 insertions, 2 deletions

diff --git a/src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h b/src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h
index f83f5ea8..856fdbdd 100644
--- a/src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h
+++ b/src/Simplex_tree/include/gudhi/Simplex_tree/Simplex_tree_iterators.h
@@ -135,14 +135,27 @@ class Simplex_tree_boundary_simplex_iterator : public boost::iterator_facade<
     }
 
     Siblings * for_sib = sib_;
-    for (auto rit = suffix_.rbegin(); rit != suffix_.rend(); ++rit) {
+    Siblings * new_sib = sib_->oncles();
+    auto rit = suffix_.rbegin();
+    if (SimplexTree::Options::contiguous_vertices
+	&& new_sib == nullptr
+	&& rit != suffix_.rend()) {
+      // We reached the root, use a short-cut to find a vertex. We could also
+      // optimize finding the second vertex of a segment, but people are
+      // expected to call endpoints().
+      assert(st_->contiguous_vertices());
+      sh_ = for_sib->members_.begin()+*rit;
+      for_sib = sh_->second.children();
+      ++rit;
+    }
+    for (; rit != suffix_.rend(); ++rit) {
       sh_ = for_sib->find(*rit);
       for_sib = sh_->second.children();
     }
     sh_ = for_sib->find(last_);  // sh_ points to the right simplex now
     suffix_.push_back(next_);
     next_ = sib_->parent();
-    sib_ = sib_->oncles();
+    sib_ = new_sib;
   }
 
   // Most of the storage should be moved to the range, iterators should be light.