mapnik/plugins/input/raster/raster_featureset.cpp

/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2017 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/debug.hpp>
#include <mapnik/image.hpp>
#include <mapnik/raster.hpp>
#include <mapnik/view_transform.hpp>
#include <mapnik/image_reader.hpp>
#include <mapnik/image_util.hpp>
#include <mapnik/feature_factory.hpp>
#include <mapnik/util/variant.hpp>

#pragma GCC diagnostic push
#include <mapnik/warning_ignore.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <boost/format.hpp>
#pragma GCC diagnostic pop

#include "raster_featureset.hpp"

using mapnik::query;
using mapnik::image_reader;
using mapnik::feature_ptr;
using mapnik::image_rgba8;
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),
      ctx_(std::make_shared<mapnik::context_type>()),
      extent_(extent),
      bbox_(q.get_bbox()),
      curIter_(policy_.begin()),
      endIter_(policy_.end()),
      filter_factor_(q.get_filter_factor())
{
}

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::unique_ptr<image_reader> reader(mapnik::get_image_reader(curIter_->file(),curIter_->format()));

            MAPNIK_LOG_DEBUG(raster) << "raster_featureset: Reader=" << curIter_->format() << "," << curIter_->file()
                                     << ",size(" << curIter_->width() << "," << curIter_->height() << ")";

            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)
                {
                    mapnik::view_transform 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);
                    // select minimum raster containing whole ext
                    int x_off = static_cast<int>(std::floor(ext.minx()));
                    int y_off = static_cast<int>(std::floor(ext.miny()));
                    int end_x = static_cast<int>(std::ceil(ext.maxx()));
                    int end_y = static_cast<int>(std::ceil(ext.maxy()));

                    // clip to available data
                    if (x_off >= image_width) x_off = image_width - 1;
                    if (y_off >= image_height) y_off = image_height - 1;
                    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;
                    if (width < 1) width = 1;
                    if (height < 1) height = 1;

                    // 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);
                    feature_raster_extent = t.backward(feature_raster_extent);
                    mapnik::image_any data = reader->read(x_off, y_off, width, height);
                    mapnik::raster_ptr raster = std::make_shared<mapnik::raster>(feature_raster_extent, intersect, std::move(data), filter_factor_);
                    feature->set_raster(raster);
                }
            }
        }
        catch (mapnik::image_reader_exception const& ex)
        {
            MAPNIK_LOG_ERROR(raster) << "Raster Plugin: image reader exception caught: " << ex.what();
        }
        catch (std::exception const& ex)
        {
            MAPNIK_LOG_ERROR(raster) << "Raster Plugin: " << ex.what();
        }
        catch (...)
        {
            MAPNIK_LOG_ERROR(raster) << "Raster Plugin: exception caught";
        }

        ++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;
    // TODO - optimize by avoiding boost::format
    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>;