[Boost-commit] svn:boost r64507 - sandbox/geometry/boost/geometry/iterators

Subject: [Boost-commit] svn:boost r64507 - sandbox/geometry/boost/geometry/iterators
From: barend.gehrels_at_[hidden]
Date: 2010-07-31 14:51:14

Author: barendgehrels
Date: 2010-07-31 14:51:13 EDT (Sat, 31 Jul 2010)
New Revision: 64507
URL: http://svn.boost.org/trac/boost/changeset/64507

Log:
added box_iterator
Added:
   sandbox/geometry/boost/geometry/iterators/box_iterator.hpp   (contents, props changed)

Added: sandbox/geometry/boost/geometry/iterators/box_iterator.hpp
==============================================================================
--- (empty file)
+++ sandbox/geometry/boost/geometry/iterators/box_iterator.hpp	2010-07-31 14:51:13 EDT (Sat, 31 Jul 2010)
@@ -0,0 +1,100 @@
+// Boost.Geometry (aka GGL, Generic Geometry Library)
+//
+// Copyright Barend Gehrels 2010, Geodan, Amsterdam, the Netherlands.
+// Use, modification and distribution is subject to the Boost Software License,
+// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_GEOMETRY_BOX_ITERATOR_HPP
+#define BOOST_GEOMETRY_BOX_ITERATOR_HPP
+
+#include <boost/iterator.hpp>
+#include <boost/iterator/iterator_facade.hpp>
+#include <boost/iterator/iterator_categories.hpp>
+
+#include <boost/geometry/core/point_type.hpp>
+#include <boost/geometry/algorithms/assign.hpp>
+
+
+namespace boost { namespace geometry
+{
+
+/*!
+    \brief Iterator which adapts a box (four points + closing) as iterator
+    \tparam Box box type on which this iterator is based on
+    \note It is always const. We cannot dereference something non-const
+        (at least not without doing tricks as returning assignables)
+    \ingroup iterators
+*/
+template <typename Box>
+struct box_iterator
+    : public boost::iterator_facade
+    <
+        box_iterator<Box>,
+        typename point_type<Box>::type const,
+        boost::bidirectional_traversal_tag
+    >
+{
+    explicit inline box_iterator(Box const& box)
+        : m_index(0)
+        , m_box_address(&box)
+    {
+        init(box);
+    }
+
+    // Constructor to indicate the end of a box
+    explicit inline box_iterator(Box const& box, bool)
+        : m_index(5)
+        , m_box_address(&box)
+    {
+        init(box);
+    }
+
+private:
+    friend class boost::iterator_core_access;
+    typedef typename point_type<Box>::type point_type;
+
+    inline point_type const& dereference() const
+    {
+        if (m_index >= 0 && m_index <= 3)
+        {
+            return m_points[m_index];
+        }
+        // If it index is 4, or other, return first point
+        return m_points[0];
+    }
+
+    inline bool equal(box_iterator<Box> const& other) const
+    {
+        return m_box_address == this->m_box_address
+            && other.m_index == this->m_index;
+    }
+
+    inline void increment()
+    {
+        m_index++;
+    }
+
+    inline void decrement()
+    {
+        m_index--;
+    }
+
+    inline void init(Box const& box)
+    {
+        // asb -> lower_left, lower_right, upper_left, upper_right
+        // we want: clockwise
+        assign_box_corners(box, m_points[0], m_points[3], m_points[1], m_points[2]);
+    }
+
+    // Copy points here - box might define them otherwise
+    point_type m_points[4];
+    int m_index;
+    Box const* const m_box_address;
+};
+
+
+}} // namespace boost::geometry
+
+
+#endif // BOOST_GEOMETRY_BOX_ITERATOR_HPP