/* This file is part of 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 Dominik Ernst

 *

 * Reflect an image about a line, whose direction is specified by the

 * vector that is defined by the x and y properties.

 */

#include "config.h"

#include <glib/gi18n-lib.h>

#ifdef GEGL_CHANT_PROPERTIES

gegl_chant_double (x, -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,

                   _("Direction vector's X component"))

gegl_chant_double (y, -G_MAXDOUBLE, G_MAXDOUBLE, 0.0,

                   _("Direction vector's Y component"))

#else

#define GEGL_CHANT_NAME reflect

#define GEGL_CHANT_SELF "reflect.c"

#include "chant.h"

#include <math.h>

static void

create_matrix (OpTransform *op,

               GeglMatrix3 *matrix)

{

  GeglChantOperation *chant = GEGL_CHANT_OPERATION (op);

  gdouble ux = 0, uy = 0;

  gdouble l;

  ux = chant->x;

  uy = chant->y;

  l = sqrt(uy*uy + ux*ux);

  ux /= l;

  uy /= l;

  matrix->coeff [0][0] = 2*ux*ux - 1;

  matrix->coeff [1][1] = 2*uy*uy - 1;

  matrix->coeff [0][1] = matrix->coeff [1][0] = 2*ux*uy;

}

#endif