root/trunk/include/mapnik/placement_finder.hpp @ 364

/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2006 Artem Pavlenko
 * Copyright (C) 2006 10East Corp.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

//$Id$

#ifndef __PLACEMENT_FINDER__
#define __PLACEMENT_FINDER__

#include <queue>

#include <mapnik/ctrans.hpp>
#include <mapnik/label_collision_detector.hpp>
#include <mapnik/text_symbolizer.hpp>
#include <mapnik/geometry.hpp>
#include <mapnik/text_path.hpp>

namespace mapnik
{

    struct placement_element
    {
        double starting_x;
        double starting_y;
    
        text_path path;
    };

  struct placement
  {
    typedef  coord_transform2<CoordTransform,geometry_type> path_type;

    //For shields
    placement(string_info *info_, CoordTransform *ctrans_, const proj_transform *proj_trans_, geometry_ptr geom_, std::pair<double, double> dimensions_);
    
    //For text
    placement(string_info *info_, CoordTransform *ctrans_, const proj_transform *proj_trans_, geometry_ptr geom_, label_placement_e placement_);
    
    ~placement();

      unsigned path_size() const;
      string_info *info;
    
    CoordTransform *ctrans;
    const proj_transform *proj_trans;

    geometry_ptr geom;
    label_placement_e label_placement;
    std::pair<double, double> dimensions;

    bool has_dimensions;
    
    path_type shape_path;
    std::queue< Envelope<double> > envelopes;
    
    //output
    std::vector<placement_element> placements;

    // caching output
    placement_element current_placement;
    
    //helpers
    std::pair<double, double> get_position_at_distance(double target_distance);
    double get_total_distance();
    void clear_envelopes();
    
    double total_distance_; //cache for distance
    
    int wrap_width;
    int text_ratio;

    int label_spacing; // distance between repeated labels on a single geometry
  };


  
  class placement_finder : boost::noncopyable
  {
  public:
    placement_finder(Envelope<double> e);
  
    bool find_placements(placement *p);
    
  protected:
    bool find_placement_follow(placement *p);
    bool find_placement_horizontal(placement *p);

    bool build_path_follow(placement *p, double target_distance);
    bool build_path_horizontal(placement *p, double target_distance);

    void update_detector(placement *p);
  
    label_collision_detector3 detector_;
  };
  
}

#endif