mapnik/plugins/input/raster/raster_featureset.cpp

/*****************************************************************************
 *
 * 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
 *
 *****************************************************************************/

// mapnik
#include <mapnik/image_reader.hpp>
#include <mapnik/image_util.hpp>
#include <mapnik/feature_factory.hpp>

// boost
#include <boost/algorithm/string/replace.hpp>

#include "raster_featureset.hpp"

using mapnik::query;
using mapnik::CoordTransform;
using mapnik::image_reader;
using mapnik::Feature;
using mapnik::feature_ptr;
using mapnik::image_data_32;
using mapnik::raster;
using mapnik::feature_factory;

template <typename LookupPolicy>
raster_featureset<LookupPolicy>::raster_featureset(LookupPolicy const& policy,
                                                   box2d<double> const& extent,
                                                   query const& q)
    : policy_(policy),
      feature_id_(1),
      extent_(extent),
      bbox_(q.get_bbox()),
      curIter_(policy_.begin()),
      endIter_(policy_.end())
{
    ctx_ = boost::make_shared<mapnik::context_type>();
}

template <typename LookupPolicy>
raster_featureset<LookupPolicy>::~raster_featureset()
{
}

template <typename LookupPolicy>
feature_ptr raster_featureset<LookupPolicy>::next()
{
    if (curIter_ != endIter_)
    {
        feature_ptr feature(feature_factory::create(ctx_,feature_id_++));

        try
        {
            std::auto_ptr<image_reader> reader(mapnik::get_image_reader(curIter_->file(),curIter_->format()));

#ifdef MAPNIK_DEBUG
            std::clog << "Raster Plugin: READER = " << curIter_->format() << " " << curIter_->file()
                      << " size(" << curIter_->width() << "," << curIter_->height() << ")" << std::endl;
#endif

            if (reader.get())
            {
                int image_width = policy_.img_width(reader->width());
                int image_height = policy_.img_height(reader->height());

                if (image_width > 0 && image_height > 0)
                {
                    CoordTransform t(image_width, image_height, extent_, 0, 0);
                    box2d<double> intersect = bbox_.intersect(curIter_->envelope());
                    box2d<double> ext = t.forward(intersect);
                    box2d<double> rem = policy_.transform(ext);
                    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 box2d of returned raster
                        box2d<double> feature_raster_extent(rem.minx() + x_off,
                                                            rem.miny() + y_off,
                                                            rem.maxx() + x_off + width,
                                                            rem.maxy() + y_off + height);
                        intersect = t.backward(feature_raster_extent);

                        image_data_32 image(width,height);
                        reader->read(x_off, y_off, image);
                        feature->set_raster(boost::make_shared<raster>(intersect, image));
                    }
                }
            }
        }
        catch (mapnik::image_reader_exception const& ex)
        {
            std::cerr << "Raster Plugin: image reader exception caught: " << ex.what() << std::endl;
        }
        catch (std::exception const& ex)
        {
            std::cerr << "Raster Plugin: " << ex.what() << std::endl;
        }
        catch (...)
        {
            std::cerr << "Raster Plugin: exception caught" << std::endl;
        }

        ++curIter_;
        return feature;
    }
    return feature_ptr();
}

std::string tiled_multi_file_policy::interpolate(std::string const& pattern, int x, int y) const
{
    // TODO: make from some sort of configurable interpolation
    int tms_y = tile_stride_ * ((image_height_ / tile_size_) - y - 1);
    int tms_x = tile_stride_ * x;
    std::string xs = (boost::format("%03d/%03d/%03d") % (tms_x / 1000000) % ((tms_x / 1000) % 1000) % (tms_x % 1000)).str();
    std::string ys = (boost::format("%03d/%03d/%03d") % (tms_y / 1000000) % ((tms_y / 1000) % 1000) % (tms_y % 1000)).str();
    std::string rv(pattern);
    boost::algorithm::replace_all(rv, "${x}", xs);
    boost::algorithm::replace_all(rv, "${y}", ys);
    return rv;
}

template class raster_featureset<single_file_policy>;
template class raster_featureset<tiled_file_policy>;
template class raster_featureset<tiled_multi_file_policy>;