
/* !!!! 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 !!!!!
 */
#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       "overlay.c"

#include "gegl-chant.h"

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;

  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 (2 * cB > aB)
            out[j] = CLAMP (2 * cA * cB + cA * (1 - aB) + cB * (1 - aA), 0, aD);
          else
            out[j] = CLAMP (aA * aB - 2 * (aB - cB) * (aA - cA) + cA * (1 - aB) + cB * (1 - aA), 0, aD);
        }
      out[3] = aD;
      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;

  operation_class->name        = "gegl:overlay";
  operation_class->description =
        _("SVG blend operation overlay (<tt>if 2 * cB > aB: d = 2 * cA * cB + cA * (1 - aB) + cB * (1 - aA) otherwise: d = aA * aB - 2 * (aB - cB) * (aA - cA) + cA * (1 - aB) + cB * (1 - aA)</tt>)");
  operation_class->categories  = "compositors:svgfilter";
}

#endif
