text: /*
   * Copyright (C) 2007,2008   Alex Shulgin
   *
   * This file is part of png++ the C++ wrapper for libpng.  PNG++ is free
   * software; the exact copying conditions are as follows:
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   *
   * 3. The name of the author may not be used to endorse or promote products
   * derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
   * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
   * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  #include <iostream>
  #include <ostream>
  
  #include <png.hpp>
  
  template< class pixel >
  void
  generate_image(png::image< pixel >& image, char const* filename)
  {
      for (size_t j = 0; j < image.get_height(); ++j)
      {
          for (size_t i = 0; i < image.get_width(); ++i)
          {
              image.set_pixel(i, j, pixel(i + j));
          }
      }
      image.write(filename);
  }
  
  int
  main(int argc, char* argv[])
  try
  {
      size_t const width = 32;
      size_t const height = 32;
  
      png::image< png::gray_pixel_1 > image1(width, height);
      generate_image(image1, "gray_packed_1.png.out");
  
      png::image< png::gray_pixel_2 > image2(width, height);
      generate_image(image2, "gray_packed_2.png.out");
  
      png::image< png::gray_pixel_4 > image4(width, height);
      generate_image(image4, "gray_packed_4.png.out");
  }
  catch (std::exception const& error)
  {
      std::cerr << "generate_gray_packed: " << error.what() << std::endl;
      return EXIT_FAILURE;
  }
  