119 lines
4.4 KiB
C++
119 lines
4.4 KiB
C++
/*****************************************************************************
|
|
*
|
|
* This file is part of Mapnik (c++ mapping toolkit)
|
|
*
|
|
* Copyright (C) 2011 Artem Pavlenko
|
|
*
|
|
* 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
|
|
*
|
|
*****************************************************************************/
|
|
|
|
#ifndef MAPNIK_METAWRITER_INMEM_HPP
|
|
#define MAPNIK_METAWRITER_INMEM_HPP
|
|
|
|
// mapnik
|
|
#include <mapnik/config.hpp>
|
|
#include <mapnik/metawriter.hpp>
|
|
|
|
// boost
|
|
#include <boost/shared_ptr.hpp>
|
|
|
|
// stl
|
|
#include <list>
|
|
|
|
namespace mapnik {
|
|
|
|
/**
|
|
* Keeps metadata information in-memory, where it can be retrieved by whatever's
|
|
* calling Mapnik and custom output provided.
|
|
*
|
|
* Stored data is all in image coordinates in the current implementation.
|
|
*
|
|
* This is most useful when Mapnik is being called from Python, and the result
|
|
* of the metawriter can be queried and injected into the (meta)tile or whatever
|
|
* in a very flexible way. E.g: for a GUI app the metawriter can be used to
|
|
* create hit areas, for a web app it could be used to create an HTML image map.
|
|
*
|
|
* Because this is kept in-memory, applying this metawriter to features which are
|
|
* very common in the rendered image will increase memory usage, especially if
|
|
* many attributes are also kept.
|
|
*/
|
|
class MAPNIK_DECL metawriter_inmem
|
|
: public metawriter, private boost::noncopyable {
|
|
public:
|
|
/**
|
|
* Construct an in-memory writer which keeps properties specified by the
|
|
* dflt_properties argument. For example: if dflt_properties contains "name",
|
|
* then the name attribute of rendered features referencing this metawriter
|
|
* will be kept in memory.
|
|
*/
|
|
metawriter_inmem(metawriter_properties dflt_properties);
|
|
~metawriter_inmem();
|
|
|
|
virtual void add_box(box2d<double> const& box, Feature const& feature,
|
|
CoordTransform const& t,
|
|
metawriter_properties const& properties);
|
|
virtual void add_text(boost::ptr_vector<text_path> &placements,
|
|
box2d<double> const& extents,
|
|
Feature const& feature,
|
|
CoordTransform const& t,
|
|
metawriter_properties const& properties);
|
|
virtual void add_polygon(path_type & path,
|
|
Feature const& feature,
|
|
CoordTransform const& t,
|
|
metawriter_properties const& properties);
|
|
virtual void add_line(path_type & path,
|
|
Feature const& feature,
|
|
CoordTransform const& t,
|
|
metawriter_properties const& properties);
|
|
|
|
virtual void start(metawriter_property_map const& properties);
|
|
|
|
/**
|
|
* An instance of a rendered feature. The box represents the image
|
|
* coordinates of a bounding box around the feature. The properties
|
|
* are the intersection of the features' properties and the "kept"
|
|
* properties of the metawriter.
|
|
*/
|
|
struct MAPNIK_DECL meta_instance {
|
|
box2d<double> box;
|
|
std::map<std::string, value> properties;
|
|
};
|
|
|
|
typedef std::list<meta_instance> meta_instance_list;
|
|
|
|
// const-only access to the instances.
|
|
const meta_instance_list &instances() const;
|
|
|
|
// utility iterators for use in the python bindings.
|
|
meta_instance_list::const_iterator inst_begin() const;
|
|
meta_instance_list::const_iterator inst_end() const;
|
|
|
|
private:
|
|
|
|
std::list<meta_instance> instances_;
|
|
|
|
void add_vertices(path_type & path,
|
|
Feature const& feature,
|
|
CoordTransform const& t,
|
|
metawriter_properties const& properties);
|
|
};
|
|
|
|
/** Shared pointer to metawriter_inmem object. */
|
|
typedef boost::shared_ptr<metawriter_inmem> metawriter_inmem_ptr;
|
|
|
|
}
|
|
|
|
#endif // MAPNIK_METAWRITER_INMEM_HPP
|