mapnik/plugins/input/raster/raster_featureset.cpp

118 lines
4.2 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2006 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
*
*****************************************************************************/
// mapnik
#include <mapnik/image_reader.hpp>
#include <mapnik/image_util.hpp>
#include "raster_featureset.hpp"
using mapnik::query;
using mapnik::CoordTransform;
using mapnik::ImageReader;
using mapnik::Feature;
using mapnik::feature_ptr;
using mapnik::ImageData32;
using mapnik::raster;
template <typename LookupPolicy>
raster_featureset<LookupPolicy>::raster_featureset(LookupPolicy const& policy,
Envelope<double> const& extent,
query const& q)
: policy_(policy),
id_(1),
extent_(extent),
bbox_(q.get_bbox()),
curIter_(policy_.begin()),
endIter_(policy_.end())
{}
template <typename LookupPolicy>
raster_featureset<LookupPolicy>::~raster_featureset() {}
template <typename LookupPolicy>
feature_ptr raster_featureset<LookupPolicy>::next()
{
if (curIter_!=endIter_)
{
feature_ptr feature(new Feature(++id_));
try
{
std::auto_ptr<ImageReader> reader(mapnik::get_image_reader(curIter_->file(),curIter_->format()));
#ifdef MAPNIK_DEBUG
std::cout << "Raster Plugin: READER = " << curIter_->format() << " " << curIter_->file()
<< " size(" << curIter_->width() << "," << curIter_->height() << ")\n";
#endif
if (reader.get())
{
int image_width=reader->width();
int image_height=reader->height();
if (image_width>0 && image_height>0)
{
CoordTransform t(image_width,image_height,extent_,0,0);
Envelope<double> intersect=bbox_.intersect(curIter_->envelope());
Envelope<double> ext=t.forward(intersect);
if ( ext.width()>0.5 && ext.height()>0.5 )
{
//select minimum raster containing whole ext
int x_off = static_cast<int>(floor(ext.minx()));
int y_off = static_cast<int>(floor(ext.miny()));
int end_x = static_cast<int>(ceil(ext.maxx()));
int end_y = static_cast<int>(ceil(ext.maxy()));
//clip to available data
if (x_off < 0)
x_off = 0;
if (y_off < 0)
y_off = 0;
if (end_x > image_width)
end_x = image_width;
if (end_y > image_height)
end_y = image_height;
int width = end_x - x_off;
int height = end_y - y_off;
//calculate actual envelope of returned raster
Envelope<double> feature_raster_extent(x_off, y_off, x_off+width, y_off+height);
intersect = t.backward(feature_raster_extent);
ImageData32 image(width,height);
reader->read(x_off,y_off,image);
feature->set_raster(mapnik::raster_ptr(new raster(intersect,image)));
}
}
}
}
catch (...)
{
std::cerr << "Raster Plugin: Exception caught\n";
}
++curIter_;
return feature;
}
return feature_ptr();
}
template class raster_featureset<single_file_policy>;
template class raster_featureset<tiled_file_policy>;