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 = static_cast<int>(ext.minx());
        int start_y = static_cast<int>(ext.miny());
        int end_x = static_cast<int>(ceil(ext.maxx()));
        int end_y = static_cast<int>(ceil(ext.maxy()));
        int raster_width = end_x - start_x;
        int raster_height = end_y - start_y;
        if (raster_width > 0 && raster_height > 0)
        {
            image_data_32 target_data(raster_width,raster_height);
            raster target(target_ext, target_data);
            scaling_method_e scaling_method = sym.get_scaling_method();
            double filter_radius = sym.calculate_filter_factor();
            double offset_x = ext.minx() - start_x;
            double offset_y = ext.miny() - start_y;
            if (!prj_trans.equal())
            {
                reproject_and_scale_raster(target, *source, prj_trans,
                                 offset_x, offset_y,
                                 sym.get_mesh_size(),
                                 filter_radius,
                                 scaling_method);
            }
            else
            {
                if (scaling_method == SCALING_BILINEAR8){
                    scale_image_bilinear8<image_data_32>(target.data_,source->data_, offset_x, offset_y);
                } else {
                    double scaling_ratio = ext.width() / source->data_.width();
                    scale_image_agg<image_data_32>(target.data_,
                                                   source->data_,
                                                   scaling_method,
                                                   scaling_ratio,
                                                   offset_x,
                                                   offset_y,
                                                   filter_radius);
                }
            }
            composite(current_buffer_->data(), target.data_, sym.comp_op(), sym.get_opacity(), start_x, start_y, true);
        }
    }
}
void agg_renderer<T>::process(raster_symbolizer const& sym,
                              mapnik::feature_ptr const& 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, false, false);
        }
    }
}