/* 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 2007 Mark Probst <mark.probst@gmail.com>
*/
#include "config.h"
#include <glib/gi18n-lib.h>
#ifdef GEGL_CHANT_PROPERTIES
gegl_chant_int (sampling_points, _("Sample points"), 0, 65536, 0,
_("Number of curve sampling points. 0 for exact calculation."))
gegl_chant_curve (curve, _("Curve"), _("The contrast curve."))
#else
#define GEGL_CHANT_TYPE_POINT_FILTER
#define GEGL_CHANT_C_FILE "contrast-curve.c"
#include "gegl-chant.h"
static void prepare (GeglOperation *operation)
{
const Babl *format = babl_format ("YA float");
gegl_operation_set_format (operation, "input", format);
gegl_operation_set_format (operation, "output", format);
}
static gboolean
process (GeglOperation *op,
void *in_buf,
void *out_buf,
glong samples,
const GeglRectangle *roi,
gint level)
{
GeglChantO *o = GEGL_CHANT_PROPERTIES (op);
gint num_sampling_points;
GeglCurve *curve;
gint i;
gfloat *in = in_buf;
gfloat *out = out_buf;
gdouble *xs, *ys;
num_sampling_points = o->sampling_points;
curve = o->curve;
if (num_sampling_points > 0)
{
xs = g_new(gdouble, num_sampling_points);
ys = g_new(gdouble, num_sampling_points);
gegl_curve_calc_values(o->curve, 0.0, 1.0, num_sampling_points, xs, ys);
g_free(xs);
for (i=0; i<samples; i++)
{
gint x = in[0] * num_sampling_points;
gfloat y;
if (x < 0)
y = ys[0];
else if (x >= num_sampling_points)
y = ys[num_sampling_points - 1];
else
y = ys[x];
out[0] = y;
out[1]=in[1];
in += 2;
out+= 2;
}
g_free(ys);
}
else
for (i=0; i<samples; i++)
{
gfloat u = in[0];
out[0] = gegl_curve_calc_value(curve, u);
out[1]=in[1];
in += 2;
out+= 2;
}
return TRUE;
}
static void
gegl_chant_class_init (GeglChantClass *klass)
{
GeglOperationClass *operation_class;
GeglOperationPointFilterClass *point_filter_class;
operation_class = GEGL_OPERATION_CLASS (klass);
point_filter_class = GEGL_OPERATION_POINT_FILTER_CLASS (klass);
point_filter_class->process = process;
operation_class->prepare = prepare;
gegl_operation_class_set_keys (operation_class,
"name" , "gegl:contrast-curve",
"categories" , "color",
"description",
_("Adjusts the contrast of the image according to a curve."),
NULL);
}
#endif