gimp/modules/display-filter-gamma.c

277 lines
7.9 KiB
C

/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1999 Manish Singh <yosh@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 <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <gegl.h>
#include <gtk/gtk.h>
#include "libgimpcolor/gimpcolor.h"
#include "libgimpconfig/gimpconfig.h"
#include "libgimpmath/gimpmath.h"
#include "libgimpmodule/gimpmodule.h"
#include "libgimpwidgets/gimpwidgets.h"
#include "libgimp/libgimp-intl.h"
#define DEFAULT_GAMMA 1.0
#define CDISPLAY_TYPE_GAMMA (cdisplay_gamma_get_type ())
#define CDISPLAY_GAMMA(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), CDISPLAY_TYPE_GAMMA, CdisplayGamma))
#define CDISPLAY_GAMMA_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), CDISPLAY_TYPE_GAMMA, CdisplayGammaClass))
#define CDISPLAY_IS_GAMMA(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), CDISPLAY_TYPE_GAMMA))
#define CDISPLAY_IS_GAMMA_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), CDISPLAY_TYPE_GAMMA))
typedef struct _CdisplayGamma CdisplayGamma;
typedef struct _CdisplayGammaClass CdisplayGammaClass;
struct _CdisplayGamma
{
GimpColorDisplay parent_instance;
gdouble gamma;
guchar lookup[256];
};
struct _CdisplayGammaClass
{
GimpColorDisplayClass parent_instance;
};
enum
{
PROP_0,
PROP_GAMMA
};
GType cdisplay_gamma_get_type (void);
static void cdisplay_gamma_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec);
static void cdisplay_gamma_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec);
static void cdisplay_gamma_convert_surface (GimpColorDisplay *display,
cairo_surface_t *surface);
static GtkWidget * cdisplay_gamma_configure (GimpColorDisplay *display);
static void cdisplay_gamma_set_gamma (CdisplayGamma *gamma,
gdouble value);
static const GimpModuleInfo cdisplay_gamma_info =
{
GIMP_MODULE_ABI_VERSION,
N_("Gamma color display filter"),
"Manish Singh <yosh@gimp.org>",
"v0.2",
"(c) 1999, released under the GPL",
"October 14, 2000"
};
G_DEFINE_DYNAMIC_TYPE (CdisplayGamma, cdisplay_gamma,
GIMP_TYPE_COLOR_DISPLAY)
G_MODULE_EXPORT const GimpModuleInfo *
gimp_module_query (GTypeModule *module)
{
return &cdisplay_gamma_info;
}
G_MODULE_EXPORT gboolean
gimp_module_register (GTypeModule *module)
{
cdisplay_gamma_register_type (module);
return TRUE;
}
static void
cdisplay_gamma_class_init (CdisplayGammaClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GimpColorDisplayClass *display_class = GIMP_COLOR_DISPLAY_CLASS (klass);
object_class->get_property = cdisplay_gamma_get_property;
object_class->set_property = cdisplay_gamma_set_property;
GIMP_CONFIG_INSTALL_PROP_DOUBLE (object_class, PROP_GAMMA,
"gamma", NULL,
0.01, 10.0, DEFAULT_GAMMA,
0);
display_class->name = _("Gamma");
display_class->help_id = "gimp-colordisplay-gamma";
display_class->stock_id = GIMP_STOCK_DISPLAY_FILTER_GAMMA;
display_class->convert_surface = cdisplay_gamma_convert_surface;
display_class->configure = cdisplay_gamma_configure;
}
static void
cdisplay_gamma_class_finalize (CdisplayGammaClass *klass)
{
}
static void
cdisplay_gamma_init (CdisplayGamma *gamma)
{
}
static void
cdisplay_gamma_get_property (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec)
{
CdisplayGamma *gamma = CDISPLAY_GAMMA (object);
switch (property_id)
{
case PROP_GAMMA:
g_value_set_double (value, gamma->gamma);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
cdisplay_gamma_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
CdisplayGamma *gamma = CDISPLAY_GAMMA (object);
switch (property_id)
{
case PROP_GAMMA:
cdisplay_gamma_set_gamma (gamma, g_value_get_double (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
cdisplay_gamma_convert_surface (GimpColorDisplay *display,
cairo_surface_t *surface)
{
CdisplayGamma *gamma = CDISPLAY_GAMMA (display);
gint width = cairo_image_surface_get_width (surface);
gint height = cairo_image_surface_get_height (surface);
gint stride = cairo_image_surface_get_stride (surface);
guchar *buf = cairo_image_surface_get_data (surface);
cairo_format_t fmt = cairo_image_surface_get_format (surface);
gint i, j, skip;
gint r, g, b, a;
if (fmt != CAIRO_FORMAT_ARGB32)
return;
/* You will not be using the entire buffer most of the time.
* Hence, the simplistic code for this is as follows:
*
* for (j = 0; j < height; j++)
* {
* for (i = 0; i < width * bpp; i++)
* buf[i] = lookup[buf[i]];
* buf += bpl;
* }
*/
j = height;
skip = stride - 4 * width;
while (j--)
{
i = width;
while (i--)
{
GIMP_CAIRO_ARGB32_GET_PIXEL (buf, r, g, b, a);
r = gamma->lookup[r];
g = gamma->lookup[g];
b = gamma->lookup[b];
GIMP_CAIRO_ARGB32_SET_PIXEL (buf, r, g, b, a);
buf += 4;
}
buf += skip;
}
}
static GtkWidget *
cdisplay_gamma_configure (GimpColorDisplay *display)
{
CdisplayGamma *gamma = CDISPLAY_GAMMA (display);
GtkWidget *hbox;
GtkWidget *label;
GtkWidget *spinbutton;
hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
label = gtk_label_new_with_mnemonic (_("_Gamma:"));
gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, FALSE, 0);
gtk_widget_show (label);
spinbutton = gimp_prop_spin_button_new (G_OBJECT (gamma), "gamma",
0.1, 1.0, 3);
gtk_box_pack_start (GTK_BOX (hbox), spinbutton, FALSE, FALSE, 0);
gtk_widget_show (spinbutton);
gtk_label_set_mnemonic_widget (GTK_LABEL (label), spinbutton);
return hbox;
}
static void
cdisplay_gamma_set_gamma (CdisplayGamma *gamma,
gdouble value)
{
if (value <= 0.0)
value = 1.0;
if (value != gamma->gamma)
{
gdouble one_over_gamma = 1.0 / value;
gint i;
gamma->gamma = value;
for (i = 0; i < 256; i++)
{
gdouble ind = (gdouble) i / 255.0;
gamma->lookup[i] = (guchar) (gint) (255 * pow (ind, one_over_gamma));
}
g_object_notify (G_OBJECT (gamma), "gamma");
gimp_color_display_changed (GIMP_COLOR_DISPLAY (gamma));
}
}