mapnik/src/image_util.cpp

/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2006 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: image_util.cpp 36 2005-04-05 14:32:18Z pavlenko $

extern "C"
{
#include <png.h>
}

// mapnik
#include <mapnik/image_util.hpp>
#include <mapnik/png_io.hpp>
#include <mapnik/graphics.hpp>
#include <mapnik/memory.hpp>
#include <mapnik/image_view.hpp>

// jpeg
#if defined(HAVE_JPEG)
#include <mapnik/jpeg_io.hpp>
#endif

#ifdef HAVE_CAIRO
#include <mapnik/cairo_renderer.hpp>
#endif

#include <boost/foreach.hpp>
#include <boost/tokenizer.hpp>

// stl
#include <string>
#include <iostream>
#include <fstream>
#include <sstream>

namespace mapnik
{    
template <typename T>
std::string save_to_string(T const& image,
                           std::string const& type)
{
    std::ostringstream ss(std::ios::out|std::ios::binary);
    save_to_stream(image, ss, type);
    return ss.str();
}

template <typename T>
void save_to_file(T const& image,
                  std::string const& filename,
                  std::string const& type)
{
    std::ofstream file (filename.c_str(), std::ios::out| std::ios::trunc|std::ios::binary);
    if (file)
    {
        save_to_stream(image, file, type);
    }
    else throw ImageWriterException("Could not write file to " + filename );
}

template <typename T>
void save_to_stream(T const& image,
                    std::ostream & stream,
                    std::string const& type)
{
    if (stream)
    {
        //all this should go into image_writer factory
        if (type == "png")  save_as_png(stream, image);
        else if (boost::algorithm::istarts_with(type, std::string("png256")) ||
                 boost::algorithm::istarts_with(type, std::string("png8"))
            ) 
        {
            int colors  = 256;
            int trans_mode = -1;
            double gamma = -1;
            bool use_octree = true;
            if (type.length() > 6){
                boost::char_separator<char> sep(":");
                boost::tokenizer< boost::char_separator<char> > tokens(type, sep);
                BOOST_FOREACH(string t, tokens)
                {
                    if (t == "m=h")
                    {
                        use_octree = false;
                    }
                    if (t == "m=o")
                    {
                        use_octree = true;
                    }
                    if (boost::algorithm::istarts_with(t,std::string("c=")))
                    {
                        try 
                        {
                            colors = boost::lexical_cast<int>(t.substr(2));
                            if (colors < 0 || colors > 256)
                                throw ImageWriterException("invalid color parameter: " + t.substr(2) + " out of bounds");
                        }
                        catch(boost::bad_lexical_cast &)
                        {
                            throw ImageWriterException("invalid color parameter: " + t.substr(2));
                        }
                    }
                    if (boost::algorithm::istarts_with(t, std::string("t=")))
                    {
                        try 
                        {
                            trans_mode= boost::lexical_cast<int>(t.substr(2));
                            if (trans_mode < 0 || trans_mode > 2)
                                throw ImageWriterException("invalid trans_mode parameter: " + t.substr(2) + " out of bounds");
                        }
                        catch(boost::bad_lexical_cast &)
                        {
                            throw ImageWriterException("invalid trans_mode parameter: " + t.substr(2));
                        }
                    }
                    if (boost::algorithm::istarts_with(t, std::string("g=")))
                    {
                        try 
                        {
                            gamma= boost::lexical_cast<double>(t.substr(2));
                            if (gamma < 0)
                                throw ImageWriterException("invalid gamma parameter: " + t.substr(2) + " out of bounds");
                        }
                        catch(boost::bad_lexical_cast &)
                        {
                            throw ImageWriterException("invalid gamma parameter: " + t.substr(2));
                        }
                    }
                }

            }
            if (use_octree)
                save_as_png256(stream, image, colors);
            else
                save_as_png256_hex(stream, image, colors, trans_mode, gamma);
        }
#if defined(HAVE_JPEG)
        else if (boost::algorithm::istarts_with(type,std::string("jpeg")))
        {
            int quality = 85;
            try 
            {
                if(type.substr(4).length() != 0)
                {
                    quality = boost::lexical_cast<int>(type.substr(4));
                    if(quality<0 || quality>100)
                        throw ImageWriterException("invalid jpeg quality: " + type.substr(4) + " out of bounds");
                }
                save_as_jpeg(stream, quality, image); 
            } 
            catch(boost::bad_lexical_cast &)
            {
                throw ImageWriterException("invalid jpeg quality: " + type.substr(4) + " not a number");
            }
        }
#endif
        else throw ImageWriterException("unknown file type: " + type);
    } 
    else throw ImageWriterException("Could not write to empty stream" );
}
        
        
template <typename T>
void save_to_file(T const& image,std::string const& filename)
{
    boost::optional<std::string> type = type_from_filename(filename);
    if (type)
    {
        save_to_file<T>(image,filename,*type);
    }
}

#if defined(HAVE_CAIRO)
// TODO - move to separate cairo_io.hpp
void save_to_cairo_file(mapnik::Map const& map, std::string const& filename)
{
    boost::optional<std::string> type = type_from_filename(filename);
    if (type)
    {
        save_to_cairo_file(map,filename,*type);
    }
}

void save_to_cairo_file(mapnik::Map const& map,
                        std::string const& filename,
                        std::string const& type)
{
    std::ofstream file (filename.c_str(), std::ios::out|std::ios::trunc|std::ios::binary);
    if (file)
    {
        Cairo::RefPtr<Cairo::Surface> surface;
        unsigned width = map.getWidth();
        unsigned height = map.getHeight();
        if (type == "pdf")
            surface = Cairo::PdfSurface::create(filename,width,height);
        else if (type == "svg")
            surface = Cairo::SvgSurface::create(filename,width,height);
        else if (type == "ps")
            surface = Cairo::PsSurface::create(filename,width,height);
        else if (type == "ARGB32")
            surface = Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32,width,height);
        else if (type == "RGB24")
            surface = Cairo::ImageSurface::create(Cairo::FORMAT_RGB24,width,height);
        else 
            throw ImageWriterException("unknown file type: " + type);    
        Cairo::RefPtr<Cairo::Context> context = Cairo::Context::create(surface);
    
        // TODO - expose as user option
        /*
          if (type == "ARGB32" || type == "RGB24") 
          { 
          context->set_antialias(Cairo::ANTIALIAS_NONE); 
          }
        */
          
    
        mapnik::cairo_renderer<Cairo::Context> ren(map, context);
        ren.apply();
    
        if (type == "ARGB32" || type == "RGB24") 
        { 
            surface->write_to_png(filename);
        }
        surface->finish();
    }
}

#endif

template void save_to_file<image_data_32>(image_data_32 const&,
                                          std::string const&,
                                          std::string const&);

template void save_to_file<image_data_32>(image_data_32 const&,
                                          std::string const&);

template std::string save_to_string<image_data_32>(image_data_32 const&,
                                                   std::string const&);

template void save_to_file<image_view<image_data_32> > (image_view<image_data_32> const&,
                                                        std::string const&,
                                                        std::string const&);
   
template void save_to_file<image_view<image_data_32> > (image_view<image_data_32> const&,
                                                        std::string const&);
   
template std::string save_to_string<image_view<image_data_32> > (image_view<image_data_32> const&,
                                                                 std::string const&);

}