process_raster_symbolizer.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/agg_renderer.hpp>
#include <mapnik/image_compositing.hpp>
#include <mapnik/graphics.hpp>
#include <mapnik/agg_rasterizer.hpp>
#include <mapnik/image_data.hpp>
#include <mapnik/image_util.hpp>
#include <mapnik/raster.hpp>
#include <mapnik/box2d.hpp>
#include <mapnik/warp.hpp>
#include <mapnik/config.hpp>

// stl
#include <cmath>


namespace mapnik {


template <typename T>
void agg_renderer<T>::process(raster_symbolizer const& sym,
                              mapnik::feature_impl & feature,
                              proj_transform const& prj_trans)
{
    raster_ptr const& source=feature.get_raster();
    if (source)
    {
        // If there's a colorizer defined, use it to color the raster in-place
        raster_colorizer_ptr colorizer = sym.get_colorizer();
        if (colorizer)
            colorizer->colorize(source,feature);

        box2d<double> target_ext = box2d<double>(source->ext_);
        prj_trans.backward(target_ext, PROJ_ENVELOPE_POINTS);

        box2d<double> ext=t_.forward(target_ext);
        int start_x = (int)ext.minx();
        int start_y = (int)ext.miny();
        int end_x = (int)ceil(ext.maxx());
        int end_y = (int)ceil(ext.maxy());
        int raster_width = end_x - start_x;
        int raster_height = end_y - start_y;
        double err_offs_x = ext.minx() - start_x;
        double err_offs_y = ext.miny() - start_y;

        if (raster_width > 0 && raster_height > 0)
        {
            double scale_factor = ext.width() / source->data_.width();
            image_data_32 target_data(raster_width,raster_height);
            raster target(target_ext, target_data);
            reproject_raster(target, *source, prj_trans, err_offs_x, err_offs_y,
                             sym.get_mesh_size(),
                             sym.calculate_filter_factor(),
                             scale_factor,
                             sym.get_scaling());

            composite(current_buffer_->data(), target.data_, sym.comp_op(), sym.get_opacity(), start_x, start_y, true);
        }
    }
}

template void agg_renderer<image_32>::process(raster_symbolizer const&,
                                              mapnik::feature_impl &,
                                              proj_transform const&);

}