/* 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 2006-2010 Øyvind Kolås <pippin@gimp.org>

 */

#include "config.h"

#include <glib/gi18n-lib.h>

#ifdef GEGL_CHANT_PROPERTIES

/* no properties */

#else

#define GEGL_CHANT_TYPE_POINT_COMPOSER3

#define GEGL_CHANT_C_FILE        "remap.c"

#include "gegl-chant.h"

static void prepare (GeglOperation *operation)

{

  const Babl *format = babl_format ("RGBA float");

  gegl_operation_set_format (operation, "input",  format);

  gegl_operation_set_format (operation, "aux",    format);

  gegl_operation_set_format (operation, "aux2",   format);

  gegl_operation_set_format (operation, "output", format);

}

static gboolean

process (GeglOperation        *op,

          void                *in_buf,

          void                *min_buf,

          void                *max_buf,

          void                *out_buf,

          glong                n_pixels,

          const GeglRectangle *roi,

          gint                 level)

{

  gint i;

  gfloat *in = in_buf;

  gfloat *min = min_buf;

  gfloat *max = max_buf;

  gfloat *out = out_buf;

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

    {

       gint c;

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

         {

           gfloat delta = max[c]-min[c];

           if (delta > 0.0001 || delta < -0.0001)

             out[c] = (in[c]-min[c]) / delta;

           else

             out[c] = in[c];

           out[3] = in[3];

         }

      in  += 4;

      out += 4;

      min += 4;

      max += 4;

    }

  return TRUE;

}

static void

gegl_chant_class_init (GeglChantClass *klass)

{

  GeglOperationClass               *operation_class;

  GeglOperationPointComposer3Class *point_composer3_class;

  operation_class       = GEGL_OPERATION_CLASS (klass);

  point_composer3_class = GEGL_OPERATION_POINT_COMPOSER3_CLASS (klass);

  operation_class->prepare = prepare;

  point_composer3_class->process = process;

  gegl_operation_class_set_keys (operation_class,

    "name"       , "gegl:remap",

    "description",

          _("stretch components of pixels individually based on luminance envelopes"),

    "categories" , "compositors:porter-duff",

    NULL);

}

#endif