mapnik/src/agg/process_polygon_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
 *
 *****************************************************************************/
//$Id$

// boost
#include <boost/foreach.hpp>
// mapnik
#include <mapnik/agg_renderer.hpp>
#include <mapnik/agg_helpers.hpp>
#include <mapnik/agg_rasterizer.hpp>
#include <mapnik/polygon_symbolizer.hpp>
#include <mapnik/vertex_converters.hpp>

// agg
#include "agg_basics.h"
#include "agg_rendering_buffer.h"
#include "agg_pixfmt_rgba.h"
#include "agg_rasterizer_scanline_aa.h"
#include "agg_scanline_u.h"

namespace mapnik {

template <typename T>
void agg_renderer<T>::process(polygon_symbolizer const& sym,
                              mapnik::feature_ptr const& feature,
                              proj_transform const& prj_trans)
{
    
    ras_ptr->reset();
    set_gamma_method(sym,ras_ptr);

    box2d<double> inflated_extent = query_extent_ * 1.1;
    
    typedef boost::mpl::vector<clip_poly_tag,transform_tag,smooth_tag> conv_types;
    vertex_converter<box2d<double>,rasterizer,polygon_symbolizer, proj_transform, CoordTransform,conv_types> 
        converter(inflated_extent,*ras_ptr,sym,t_,prj_trans);
    
    if (sym.clip()) converter.set<clip_poly_tag>(); //optinal clip (default: true) 
    converter.set<transform_tag>(); //always transform 
    if (sym.smooth() > 0.0) converter.set<smooth_tag>(); // optional smooth converter
    
    BOOST_FOREACH( geometry_type & geom, feature->paths())
    {
        if (geom.num_points() > 2)
        {          
            converter.apply(geom);
        }
    }
    
    agg::rendering_buffer buf(current_buffer_->raw_data(),width_,height_, width_ * 4);

    color const& fill = sym.get_fill();
    unsigned r=fill.red();
    unsigned g=fill.green();
    unsigned b=fill.blue();
    unsigned a=fill.alpha();
    
    if (sym.comp_op() == clear)
    {
        aa_renderer::pixfmt_type pixf(buf);
        aa_renderer ren;
        ren.attach(pixf);
        ren.color(agg::rgba8(r, g, b, int(a * sym.get_opacity())));
        ren.render(*ras_ptr);
    }
    else
    {   
        typedef agg::rgba8 color_type;
        typedef agg::order_rgba order_type;
        typedef agg::pixel32_type pixel_type;
        typedef agg::comp_op_adaptor_rgba<color_type, order_type> blender_type; // comp blender
        typedef agg::pixfmt_custom_blend_rgba<blender_type, agg::rendering_buffer> pixfmt_comp_type;
        typedef agg::renderer_base<pixfmt_comp_type> renderer_base;
        typedef agg::renderer_scanline_aa_solid<renderer_base> renderer_type;     
        pixfmt_comp_type pixf(buf);
        pixf.comp_op(static_cast<agg::comp_op_e>(sym.comp_op()));
        renderer_base renb(pixf);
        renderer_type ren(renb);
        ren.color(agg::rgba8(r, g, b, int(a * sym.get_opacity())));
        agg::scanline_u8 sl;
        agg::render_scanlines(*ras_ptr, sl, ren);
    }
    
}

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

}