#!/usr/bin/env ruby

copyright = '
/* !!!! AUTOGENERATED FILE generated by other-blend.rb !!!!!
 *
 * This file is an image processing operation for GEGL
 *
 * GEGL 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 3 of the License, or (at your option) any later version.
 *
 * GEGL 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 GEGL; if not, see <http://www.gnu.org/licenses/>.
 *
 *  Copyright 2006,2007 Øyvind Kolås <pippin@gimp.org>
 *            2007 John Marshall
 *
 * SVG rendering modes; see:
 *     http://www.w3.org/TR/SVG12/rendering.html
 *     http://www.w3.org/TR/2004/WD-SVG12-20041027/rendering.html#comp-op-prop
 *
 *     aA = aux(src) alpha      aB = in(dst) alpha      aD = out alpha
 *     cA = aux(src) colour     cB = in(dst) colour     cD = out colour
 *
 * !!!! AUTOGENERATED FILE !!!!!
 */'

a = [
#       Alias for porter-duff src-over
#      ['normal',  'cA + cB * (1.0f - aA)',
#                  'aA + aB - aA * aB'],
#       Alias for porter-duff src-over
#      ['over',    'cA + cB * (1.0f - aA)',
#                  'aA + aB - aA * aB'],
    ]

file_head1 = '
#include "config.h"
#include <glib/gi18n-lib.h>


#ifdef GEGL_CHANT_PROPERTIES

/* no properties */

#else
'

file_head2 = '
static void prepare (GeglOperation *operation)
{
  const Babl *format = babl_format ("RaGaBaA float");

  gegl_operation_set_format (operation, "input", format);
  gegl_operation_set_format (operation, "aux", format);
  gegl_operation_set_format (operation, "output", format);
}

static gboolean
process (GeglOperation        *op,
          void                *in_buf,
          void                *aux_buf,
          void                *out_buf,
          glong                n_pixels,
          const GeglRectangle *roi,
          gint                 level)
{
  gint i;
  gfloat * GEGL_ALIGNED in = in_buf;
  gfloat * GEGL_ALIGNED aux = aux_buf;
  gfloat * GEGL_ALIGNED out = out_buf;

  if (aux==NULL)
    return TRUE;
'

file_tail1 = '

static void
gegl_chant_class_init (GeglChantClass *klass)
{
  GeglOperationClass              *operation_class;
  GeglOperationPointComposerClass *point_composer_class;

  operation_class      = GEGL_OPERATION_CLASS (klass);
  point_composer_class = GEGL_OPERATION_POINT_COMPOSER_CLASS (klass);

  point_composer_class->process = process;
  operation_class->prepare = prepare;
'

file_tail2 = '  gegl_operation_class_set_key (operation_class, "categories", "compositors:porter-duff");
}

#endif
'

a.each do
    |item|

    name     = item[0] + ''
    name.gsub!(/_/, '-')
    filename = name + '.c'

    puts "generating #{filename}"
    file = File.open(filename, 'w')

    capitalized = name.capitalize
    swapcased   = name.swapcase
    c_formula   = item[1]
    a_formula   = item[2]

    file.write copyright
    file.write file_head1
    file.write "
#define GEGL_CHANT_TYPE_POINT_COMPOSER
#define GEGL_CHANT_C_FILE        \"#{filename}\"

#include \"gegl-chant.h\"
"
    file.write file_head2
    file.write "
  for (i = 0; i < n_pixels; i++)
    {
      gint   j;
      gfloat aA, aB, aD;

      aB = in[3];
      aA = aux[3];
      aD = #{a_formula};

      for (j = 0; j < 3; j++)
        {
          gfloat cA, cB;

          cB = in[j];
          cA = aux[j];
          out[j] = #{c_formula};
        }
      out[3] = aD;
      in  += 4;
      aux += 4;
      out += 4;
    }
  return TRUE;
}

"
  file.write file_tail1
  file.write "

  gegl_operation_class_set_keys (operation_class,
    \"name\"       , \"gegl:#{name}\";
    \"description\",
        _(\"Porter Duff operation #{name} (d = #{c_formula})\"),
        NULL);

"
  file.write file_tail2
  file.close
end