mapnik/src/metawriter.cpp
2010-08-07 20:03:05 +00:00

219 lines
6.2 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2010 Hermann Kraus
*
* 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
*
*****************************************************************************/
// Mapnik
#include <mapnik/metawriter.hpp>
#include <mapnik/metawriter_json.hpp>
// Boost
#include <boost/foreach.hpp>
#include <boost/algorithm/string.hpp>
// STL
#include <iomanip>
#include <cstdio>
#define HEADER_NOT_WRITTEN -1
#define STOPPED -2
#define STARTED 0
namespace mapnik {
UnicodeString const& metawriter_property_map::operator[](std::string const& key) const
{
std::map<std::string, UnicodeString>::const_iterator it;
it = m_.find(key);
if (it == m_.end()) return not_found_;
return (*it).second;
}
metawriter_properties::metawriter_properties(boost::optional<std::string> str)
{
if (str) {
boost::split(*this, *str, boost::is_any_of(", "), boost::token_compress_on);
}
}
/********************************************************************************************/
void metawriter_json_stream::start(metawriter_property_map const& properties)
{
assert(trans_);
if (!only_nonempty_) {
write_header();
} else {
count_ = HEADER_NOT_WRITTEN;
}
}
void metawriter_json_stream::write_header()
{
assert(f_);
*f_ << "{ \"type\": \"FeatureCollection\", \"features\": [\n";
count_ = STARTED;
}
void metawriter_json_stream::stop()
{
if (count_ >= STARTED && f_) {
*f_ << " ] }\n";
}
count_ = STOPPED;
}
metawriter_json_stream::~metawriter_json_stream()
{
if (count_ >= STARTED) {
#ifdef MAPNIK_DEBUG
std::cerr << "WARNING: GeoJSON metawriter not stopped before destroying it.";
#endif
stop();
}
if (trans_) delete trans_;
}
metawriter_json_stream::metawriter_json_stream(metawriter_properties dflt_properties)
: metawriter(dflt_properties), count_(-1), only_nonempty_(true),
trans_(0), output_srs_("+proj=latlong +datum=WGS84"), f_(0)
{
}
void metawriter_json_stream::add_box(box2d<double> const &box, Feature const& feature,
CoordTransform const& t, metawriter_properties const& properties)
{
/* Check if feature is in bounds. */
if (box.maxx() < 0 || box.maxy() < 0 || box.minx() > width_ || box.miny() > height_) return;
if (count_ == HEADER_NOT_WRITTEN) write_header();
#ifdef MAPNIK_DEBUG
if (count_ == STOPPED)
{
std::cerr << "WARNING: Metawriter not started before using it.\n";
}
#endif
/* Coordinate transform in renderer:
input: layer srs
prj_trans.backwards() [prj_trans: map -> layer]
intermediate: map srs
t_.forward()
output: pixels
Our transform:
input: pixels
t_.backward()
intermediate: map srs
trans_.forward()
output: WGS84
*/
//t_ coord transform has transform for box2d combined with proj_transform
box2d<double> transformed = t.backward(box, *trans_);
double minx = transformed.minx();
double miny = transformed.miny();
double maxx = transformed.maxx();
double maxy = transformed.maxy();
if (count_++) *f_ << ",\n";
*f_ << std::fixed << std::setprecision(8) << "{ \"type\": \"Feature\",\n \"geometry\": { \"type\": \"Polygon\",\n \"coordinates\": [ [ [" <<
minx << ", " << miny << "], [" <<
maxx << ", " << miny << "], [" <<
maxx << ", " << maxy << "], [" <<
minx << ", " << maxy << "] ] ] }," <<
"\n \"properties\": {";
std::map<std::string, value> fprops = feature.props();
int i = 0;
BOOST_FOREACH(std::string p, properties)
{
std::map<std::string, value>::const_iterator itr = fprops.find(p);
std::string text;
if (itr != fprops.end())
{
//Property found
text = boost::replace_all_copy(boost::replace_all_copy(itr->second.to_string(), "\\", "\\\\"), "\"", "\\\"");
}
if (i++) *f_ << ",";
*f_ << "\n \"" << p << "\":\"" << text << "\"";
}
*f_ << "\n} }";
}
void metawriter_json_stream::set_map_srs(projection const& input_srs_)
{
if (trans_) delete trans_;
trans_ = new proj_transform(input_srs_, output_srs_);
}
/********************************************************************************************/
metawriter_json::metawriter_json(metawriter_properties dflt_properties, path_expression_ptr fn)
: metawriter_json_stream(dflt_properties), fn_(fn) {}
void metawriter_json::start(metawriter_property_map const& properties)
{
filename_ =
path_processor<metawriter_property_map>::evaluate(*fn_, properties);
#ifdef MAPNIK_DEBUG
std::clog << "Metawriter JSON: filename=" << filename_ << "\n";
#endif
metawriter_json_stream::start(properties);
}
void metawriter_json::write_header()
{
f_.open(filename_.c_str(), std::fstream::out | std::fstream::trunc);
if (f_.fail()) perror((std::string("Metawriter JSON: Failed to open file ") + filename_).c_str());
set_stream(&f_);
metawriter_json_stream::write_header();
}
void metawriter_json::stop()
{
metawriter_json_stream::stop();
if (f_.is_open()) {
f_.close();
}
#ifdef MAPNIK_DEBUG
else {
std::clog << "WARNING: File not open in metawriter_json::stop()!\n";
}
#endif
}
void metawriter_json::set_filename(path_expression_ptr fn)
{
fn_ = fn;
}
path_expression_ptr metawriter_json::get_filename() const
{
return fn_;
}
};