#!/usr/bin/env ruby

copyright = '
/* !!!! AUTOGENERATED FILE generated by svg12-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 = [
      ['svg_multiply',  'cA * cB +  cA * (1 - aB) + cB * (1 - aA)'],
      ['screen',        'cA + cB - cA * cB'],
      ['darken',        'MIN (cA * aB, cB * aA) + cA * (1 - aB) + cB * (1 - aA)'],
      ['lighten',       'MAX (cA * aB, cB * aA) + cA * (1 - aB) + cB * (1 - aA)'],
      ['difference',    'cA + cB - 2 * (MIN (cA * aB, cB * aA))'],
      ['exclusion',     '(cA * aB + cB * aA - 2 * cA * cB) + cA * (1 - aB) + cB * (1 - aA)']
    ]

b = [
      ['overlay',       '2 * cB > aB',
                        '2 * cA * cB + cA * (1 - aB) + cB * (1 - aA)',
                        'aA * aB - 2 * (aB - cB) * (aA - cA) + cA * (1 - aB) + cB * (1 - aA)'],
      ['color_dodge',   'cA * aB + cB * aA >= aA * aB',
                        'aA * aB + cA * (1 - aB) + cB * (1 - aA)',
                        '(cA == aA ? 1 : cB * aA / (aA == 0 ? 1 : 1 - cA / aA)) + cA * (1 - aB) + cB * (1 - aA)'],

      ['color_burn',    'cA * aB + cB * aA <= aA * aB',
                        'cA * (1 - aB) + cB * (1 - aA)',
                        '(cA == 0 ? 1 : (aA * (cA * aB + cB * aA - aA * aB) / cA) + cA * (1 - aB) + cB * (1 - aA))'],
      ['hard_light',    '2 * cA < aA',
                        '2 * cA * cB + cA * (1 - aB) + cB * (1 - aA)',
                        'aA * aB - 2 * (aB - cB) * (aA - cA) + cA * (1 - aB) + cB * (1 - aA)']
    ]

c = [
      ['soft_light',    '2 * cA < aA',
                        'cB * (aA - (aB == 0 ? 1 : 1 - cB / aB) * (2 * cA - aA)) + cA * (1 - aB) + cB * (1 - aA)',
                        '8 * cB <= aB',
                        'cB * (aA - (aB == 0 ? 1 : 1 - cB / aB) * (2 * cA - aA) * (aB == 0 ? 3 : 3 - 8 * cB / aB)) + cA * (1 - aB) + cB * (1 - aA)',
                        '(aA * cB + (aB == 0 ? 0 : sqrt (cB / aB) * aB - cB) * (2 * cA - aA)) + cA * (1 - aB) + cB * (1 - aA)']
    ]

d = [
      ['plus',          'cA + cB',
                        'MIN (aA + aB, 1)']
    ]

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


#ifdef GEGL_CHANT_PROPERTIES

/* no properties */

#else
'

file_head2 = '
static void prepare (GeglOperation *operation)
{
  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)
{
  gfloat *in = in_buf;
  gfloat *aux = aux_buf;
  gfloat *out = out_buf;
  gint    i;

  if (aux==NULL)
    return TRUE;
'

file_tail1 = '
  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;
'

file_tail2 = '  operation_class->categories  = "compositors:svgfilter";
}

#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
    formula1    = item[1]

    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++)
    {
      gfloat aA, aB, aD;
      gint   j;

      aB = in[3];
      aA = aux[3];
      aD = aA + aB - aA * aB;

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

          cB = in[j];
          cA = aux[j];
          out[j] = CLAMP (#{formula1}, 0, aD);
        }
      out[3] = aD;
      in  += 4;
      aux += 4;
      out += 4;
    }
"
  file.write file_tail1
  file.write "
  operation_class->name        = \"gegl:#{name}\";
  operation_class->description =
        _(\"SVG blend operation #{name} (<tt>d = #{formula1}</tt>)\");
"
  file.write file_tail2
  file.close
end

b.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
    cond1       = item[1]
    formula1    = item[2]
    formula2    = item[3]

    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++)
    {
      gfloat aA, aB, aD;
      gint   j;

      aB = in[3];
      aA = aux[3];
      aD = aA + aB - aA * aB;

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

          cB = in[j];
          cA = aux[j];
          if (#{cond1})
            out[j] = CLAMP (#{formula1}, 0, aD);
          else
            out[j] = CLAMP (#{formula2}, 0, aD);
        }
      out[3] = aD;
      in  += 4;
      aux += 4;
      out += 4;
    }
"
  file.write file_tail1
  file.write "
  operation_class->name        = \"gegl:#{name}\";
  operation_class->description =
        _(\"SVG blend operation #{name} (<tt>if #{cond1}: d = #{formula1} otherwise: d = #{formula2}</tt>)\");
"
  file.write file_tail2
  file.close
end

c.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
    cond1       = item[1]
    formula1    = item[2]
    cond2       = item[3]
    formula2    = item[4]
    formula3    = item[5]

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

      aB = in[3];
      aA = aux[3];
      aD = aA + aB - aA * aB;

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

          cB = in[j];
          cA = aux[j];
          if (#{cond1})
            out[j] = CLAMP (#{formula1}, 0, aD);
          else if (#{cond2})
            out[j] = CLAMP (#{formula2}, 0, aD);
          else
            out[j] = CLAMP (#{formula3}, 0, aD);
        }
      out[3] = aD;
      in  += 4;
      aux += 4;
      out += 4;
    }
"
  file.write file_tail1
  file.write "
  operation_class->name        = \"gegl:#{name}\";
  operation_class->description =
        _(\"SVG blend operation #{name} (<tt>if #{cond1}: d = #{formula1}; if #{cond2}: d = #{formula2}; otherwise: d = #{formula3}</tt>)\");
"
  file.write file_tail2
  file.close
end

d.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
    formula1    = item[1]
    formula2    = 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++)
    {
      gfloat aA, aB, aD;
      gint   j;

      aB = in[3];
      aA = aux[3];
      aD = #{formula2};

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

          cB = in[j];
          cA = aux[j];
          out[j] = CLAMP (#{formula1}, 0, aD);
        }
      out[3] = aD;
      in  += 4;
      aux += 4;
      out += 4;
    }
"
  file.write file_tail1
  file.write "
  operation_class->name        = \"gegl:#{name}\";
  operation_class->description =
        _(\"SVG blend operation #{name} (<tt>d = #{formula1}</tt>)\");
"
  file.write file_tail2
  file.close
end
