gimp/app/operations/gimpoperationlevels.c

210 lines
7.6 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* gimpoperationlevels.c
* Copyright (C) 2007 Michael Natterer <mitch@gimp.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <cairo.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gegl.h>
#include "libgimpmath/gimpmath.h"
#include "operations-types.h"
#include "gimplevelsconfig.h"
#include "gimpoperationlevels.h"
#include "gimp-intl.h"
static gboolean gimp_operation_levels_process (GeglOperation *operation,
void *in_buf,
void *out_buf,
glong samples,
const GeglRectangle *roi,
gint level);
G_DEFINE_TYPE (GimpOperationLevels, gimp_operation_levels,
GIMP_TYPE_OPERATION_POINT_FILTER)
#define parent_class gimp_operation_levels_parent_class
static void
gimp_operation_levels_class_init (GimpOperationLevelsClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GeglOperationClass *operation_class = GEGL_OPERATION_CLASS (klass);
GeglOperationPointFilterClass *point_class = GEGL_OPERATION_POINT_FILTER_CLASS (klass);
object_class->set_property = gimp_operation_point_filter_set_property;
object_class->get_property = gimp_operation_point_filter_get_property;
gegl_operation_class_set_keys (operation_class,
"name", "gimp:levels",
"categories", "color",
"description", _("Adjust color levels"),
NULL);
point_class->process = gimp_operation_levels_process;
g_object_class_install_property (object_class,
GIMP_OPERATION_POINT_FILTER_PROP_TRC,
g_param_spec_enum ("trc",
"Linear/Percptual",
"What TRC to operate on",
GIMP_TYPE_TRC_TYPE,
GIMP_TRC_NON_LINEAR,
G_PARAM_READWRITE));
g_object_class_install_property (object_class,
GIMP_OPERATION_POINT_FILTER_PROP_CONFIG,
g_param_spec_object ("config",
"Config",
"The config object",
GIMP_TYPE_LEVELS_CONFIG,
G_PARAM_READWRITE |
G_PARAM_CONSTRUCT));
}
static void
gimp_operation_levels_init (GimpOperationLevels *self)
{
}
static inline gdouble
gimp_operation_levels_map (gdouble value,
gdouble low_input,
gdouble high_input,
gboolean clamp_input,
gdouble inv_gamma,
gdouble low_output,
gdouble high_output,
gboolean clamp_output)
{
/* determine input intensity */
if (high_input != low_input)
value = (value - low_input) / (high_input - low_input);
else
value = (value - low_input);
if (clamp_input)
value = CLAMP (value, 0.0, 1.0);
if (inv_gamma != 1.0 && value > 0)
value = pow (value, inv_gamma);
/* determine the output intensity */
if (high_output >= low_output)
value = value * (high_output - low_output) + low_output;
else if (high_output < low_output)
value = low_output - value * (low_output - high_output);
if (clamp_output)
value = CLAMP (value, 0.0, 1.0);
return value;
}
static gboolean
gimp_operation_levels_process (GeglOperation *operation,
void *in_buf,
void *out_buf,
glong samples,
const GeglRectangle *roi,
gint level)
{
GimpOperationPointFilter *point = GIMP_OPERATION_POINT_FILTER (operation);
GimpLevelsConfig *config = GIMP_LEVELS_CONFIG (point->config);
gfloat *src = in_buf;
gfloat *dest = out_buf;
gfloat inv_gamma[5];
gint channel;
if (! config)
return FALSE;
for (channel = 0; channel < 5; channel++)
{
g_return_val_if_fail (config->gamma[channel] != 0.0, FALSE);
inv_gamma[channel] = 1.0 / config->gamma[channel];
}
while (samples--)
{
for (channel = 0; channel < 4; channel++)
{
gdouble value;
value = gimp_operation_levels_map (src[channel],
config->low_input[channel + 1],
config->high_input[channel + 1],
config->clamp_input,
inv_gamma[channel + 1],
config->low_output[channel + 1],
config->high_output[channel + 1],
config->clamp_output);
/* don't apply the overall curve to the alpha channel */
if (channel != ALPHA)
value = gimp_operation_levels_map (value,
config->low_input[0],
config->high_input[0],
config->clamp_input,
inv_gamma[0],
config->low_output[0],
config->high_output[0],
config->clamp_output);
dest[channel] = value;
}
src += 4;
dest += 4;
}
return TRUE;
}
/* public functions */
gdouble
gimp_operation_levels_map_input (GimpLevelsConfig *config,
GimpHistogramChannel channel,
gdouble value)
{
g_return_val_if_fail (GIMP_IS_LEVELS_CONFIG (config), 0.0);
/* determine input intensity */
if (config->high_input[channel] != config->low_input[channel])
value = ((value - config->low_input[channel]) /
(config->high_input[channel] - config->low_input[channel]));
else
value = (value - config->low_input[channel]);
if (config->gamma[channel] != 0.0 && value > 0.0)
value = pow (value, 1.0 / config->gamma[channel]);
return value;
}