mapnik/bindings/python/mapnik_image.cpp

/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2006 Artem Pavlenko, Jean-Francois Doyon
 *
 * 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
 *
 *****************************************************************************/
//$Id$

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

// boost
#include <boost/python.hpp>
#include <boost/python/module.hpp>
#include <boost/python/def.hpp>
// mapnik
#include <mapnik/graphics.hpp>
#include <mapnik/image_util.hpp>
#include <mapnik/jpeg_io.hpp>
#include <mapnik/png_io.hpp>
#include <mapnik/image_reader.hpp>
#include <sstream>

using mapnik::Image32;
using mapnik::ImageReader;
using mapnik::get_image_reader;
using mapnik::type_from_filename;
using namespace boost::python;
using mapnik::save_to_file;

// output 'raw' pixels
PyObject* tostring1( Image32 const& im)
{
    int size = im.width() * im.height() * 4;
    return ::PyString_FromStringAndSize((const char*)im.raw_data(),size);
}

// encode (png,jpeg)
PyObject* tostring2(Image32 const & im, std::string const& format)
{
   std::ostringstream ss(std::ios::out|std::ios::binary);
   if (format == "png") save_as_png(ss,im.data());
   else if (format == "png256") save_as_png256(ss,im.data());
   else if (format == "jpeg") save_as_jpeg(ss,85,im.data());
   else throw mapnik::ImageWriterException("unknown format: " + format);
   return ::PyString_FromStringAndSize((const char*)ss.str().c_str(),ss.str().size());
}

void (*save_to_file1)( mapnik::Image32 const&, std::string const&,std::string const&) = mapnik::save_to_file;
void (*save_to_file2)( mapnik::Image32 const&, std::string const&) = mapnik::save_to_file;

boost::shared_ptr<Image32> open_from_file(std::string const& filename)
{
   std::auto_ptr<ImageReader> reader(get_image_reader(filename,type_from_filename(filename)));
   if (reader.get())
   {
      boost::shared_ptr<Image32> image_ptr(new Image32(reader->width(),reader->height()));
      reader->read(0,0,image_ptr->data());
      return image_ptr;
   }
   throw mapnik::ImageReaderException("FIXME: " + filename);  
}

void blend (Image32 & im, unsigned x, unsigned y, Image32 const& im2, float opacity)
{
   im.set_rectangle_alpha2(im2.data(),x,y,opacity);
}

void export_image()
{
    using namespace boost::python;
    class_<Image32,boost::shared_ptr<Image32> >("Image","This class represents a 32 bit RGBA image.",init<int,int>())
       .def("width",&Image32::width)
       .def("height",&Image32::height)
       .def("view",&Image32::get_view)
       .add_property("background",make_function
                     (&Image32::getBackground,return_value_policy<copy_const_reference>()),
                     &Image32::setBackground, "The background color of the image.")
       .def("blend",&blend)
       .def("tostring",&tostring1)
       .def("tostring",&tostring2)
       .def("save", save_to_file1)
       .def("save", save_to_file2)
       .def("open",open_from_file)
       .staticmethod("open")
       ;    
    
}