mapnik/include/label_collision_detector.hpp
2006-02-27 21:25:25 +00:00

84 lines
2 KiB
C++

/* This file is part of Mapnik (c++ mapping toolkit)
* Copyright (C) 2006 Artem Pavlenko
*
* Mapnik is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
//$Id$
#if !defined LABEL_COLLISION_DETECTOR
#define LABEL_COLLISION_DETECTOR
#include "quad_tree.hpp"
#include <vector>
namespace mapnik
{
//this needs to be tree structure
//as a proof of a concept _only_ we use sequential scan
struct label_collision_detector
{
typedef std::vector<Envelope<double> > label_placements;
bool has_plasement(Envelope<double> const& box)
{
label_placements::const_iterator itr=labels_.begin();
for( ; itr !=labels_.end();++itr)
{
if (itr->intersects(box))
{
return false;
}
}
labels_.push_back(box);
return true;
}
private:
label_placements labels_;
};
// quad_tree based label collision detector
class label_collision_detector2 : boost::noncopyable
{
typedef quad_tree<Envelope<double> > tree_t;
tree_t tree_;
public:
explicit label_collision_detector2(Envelope<double> const& extent)
: tree_(extent) {}
bool has_placement(Envelope<double> const& box)
{
tree_t::query_iterator itr = tree_.query_in_box(box);
tree_t::query_iterator end = tree_.query_end();
for ( ;itr != end; ++itr)
{
if (itr->intersects(box))
{
return false;
}
}
tree_.insert(box,box);
return true;
}
};
}
#endif