#!/usr/bin/env ruby

copyright = '

/* !!!! AUTOGENERATED FILE generated by 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 Øyvind Kolås <pippin@gimp.org>

 *

 * The formulas used for the blend modes are from:

 *     http://www.pegtop.net/delphi/articles/blendmodes/

 *

 * !!!! AUTOGENERATED FILE !!!!!

 */'

a = [

      ['average',       '(cA + aB)/2'],

      #['screen',        '1.0 - ((1.0-cA) * (1.0-cB))'],

      #['darken',        'cA < cB ? cA : cB'],

      #['lighten',       'cA > cB ? cA : cB'],

      #['difference',    'fabs(cA-cB)'],

      ['negation',      '1.0 - fabs(1.0-cA-cB)'],

      #['exclusion',     'cA + cB - 2*cA*cB'],

      #['overlay',       'cA<0.5?2*(cA*cB):1.0-2*(1.0-cA)*(1.0-cB)'],

      #['hard-light',    'cB<0.5?2*(cA*cB):1.0-2*(1.0-cA)*(1.0-cB)'],

      #['soft-light',    '2*cA*cB+cA*cA-2*cA*cA*cB'],

      #['color_dodge',   'cA / (1.0 - cB)'],

      ['soft-dodge',    '(cA+cB<1.0)?0.5*cA / (1.0 - cB):1.0-0.5*(1.0 - cB)/cA'],

      #['color_burn',    'cB<=0.0?0.0:1.0-(1.0-cA)/cB'],

      ['soft-burn',     '(cA+cB<1.0)?0.5*cB / (1.0 - cA):1.0-0.5*(1.0 - cA) / cB'],

      ['blend-reflect', 'cB>=1.0?1.0:cA*cA / (1.0-cB)'],

      ['subtractive',   'cA+cB-1.0']

    ]

a.each do

    |item|

    name     = item[0] + ''

    filename = name + '.c'

    puts "generating #{filename}"

    file = File.open(filename, 'w')

    name        = item[0]

    capitalized = name.capitalize

    swapcased   = name.swapcase

    formula     = item[1]

    file.write copyright

    file.write "

#include \"config.h\"

#include <glib/gi18n-lib.h>

#ifdef GEGL_CHANT_PROPERTIES

/* no properties */

#else

#define GEGL_CHANT_TYPE_POINT_COMPOSER

#define GEGL_CHANT_C_FILE          \"#{filename}\"

#include \"gegl-chant.h\"

#include <math.h>

static void prepare (GeglOperation *self)

{

  const Babl *format = babl_format (\"RaGaBaA float\");

  gegl_operation_set_format (self, \"input\", format);

  gegl_operation_set_format (self, \"aux\", format);

  gegl_operation_set_format (self, \"output\", format);

}

static gboolean

process (GeglOperation       *op,

         void                *in_buf,

         void                *aux_buf,

         void                *out_buf,

         glong                n_pixels,

         const GeglRectangle *roi,

         gint                 level)

{

  gfloat *in  = in_buf;

  gfloat *aux = aux_buf;

  gfloat *out = out_buf;

  gint    i;

  if (aux == NULL)

    return TRUE;

  for (i = 0; i < n_pixels; i++)

    {

      gfloat aA, aB;

      gint   j;

      aA = in[3];

      aB = aux[3];

      for (j = 0; j < 3; j++)

        {

          gfloat cA, cB;

          cA = in[j];

          cB = aux[j];

          out[j] = cA + (#{formula}-cA) * cB;

        }

      out[j] = aA;

      in  += 4;

      aux += 4;

      out += 4;

    }

  return TRUE;

}

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;

  gegl_operation_class_set_keys (operation_class,

  \"name\"        , \"gegl:#{name}\",

  \"categories\"  , \"compositors:blend\",

  \"description\" ,

        _(\"Image blending operation '#{name}' (<tt>c = #{formula}</tt>)\"),

        NULL);

}

#endif

"

  file.close

end