PIKApp/app/core/pikacurve-map.c

247 lines
7.4 KiB
C

/* PIKA - Photo and Image Kooker Application
* a rebranding of The GNU Image Manipulation Program (created with heckimp)
* A derived work which may be trivial. However, any changes may be (C)2023 by Aldercone Studio
*
* Original copyright, applying to most contents (license remains unchanged):
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 <string.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gegl.h>
#include "libpikamath/pikamath.h"
#include "core-types.h"
#include "pikacurve.h"
#include "pikacurve-map.h"
enum
{
CURVE_NONE = 0,
CURVE_COLORS = 1 << 0,
CURVE_RED = 1 << 1,
CURVE_GREEN = 1 << 2,
CURVE_BLUE = 1 << 3,
CURVE_ALPHA = 1 << 4
};
static guint pika_curve_get_apply_mask (PikaCurve *curve_colors,
PikaCurve *curve_red,
PikaCurve *curve_green,
PikaCurve *curve_blue,
PikaCurve *curve_alpha);
static inline gdouble pika_curve_map_value_inline (PikaCurve *curve,
gdouble value);
gdouble
pika_curve_map_value (PikaCurve *curve,
gdouble value)
{
g_return_val_if_fail (PIKA_IS_CURVE (curve), 0.0);
return pika_curve_map_value_inline (curve, value);
}
void
pika_curve_map_pixels (PikaCurve *curve_colors,
PikaCurve *curve_red,
PikaCurve *curve_green,
PikaCurve *curve_blue,
PikaCurve *curve_alpha,
gfloat *src,
gfloat *dest,
glong samples)
{
g_return_if_fail (PIKA_IS_CURVE (curve_colors));
g_return_if_fail (PIKA_IS_CURVE (curve_red));
g_return_if_fail (PIKA_IS_CURVE (curve_green));
g_return_if_fail (PIKA_IS_CURVE (curve_blue));
g_return_if_fail (PIKA_IS_CURVE (curve_alpha));
switch (pika_curve_get_apply_mask (curve_colors,
curve_red,
curve_green,
curve_blue,
curve_alpha))
{
case CURVE_NONE:
memcpy (dest, src, samples * 4 * sizeof (gfloat));
break;
case CURVE_COLORS:
while (samples--)
{
dest[0] = pika_curve_map_value_inline (curve_colors, src[0]);
dest[1] = pika_curve_map_value_inline (curve_colors, src[1]);
dest[2] = pika_curve_map_value_inline (curve_colors, src[2]);
/* don't apply the colors curve to the alpha channel */
dest[3] = src[3];
src += 4;
dest += 4;
}
break;
case CURVE_RED:
while (samples--)
{
dest[0] = pika_curve_map_value_inline (curve_red, src[0]);
dest[1] = src[1];
dest[2] = src[2];
dest[3] = src[3];
src += 4;
dest += 4;
}
break;
case CURVE_GREEN:
while (samples--)
{
dest[0] = src[0];
dest[1] = pika_curve_map_value_inline (curve_green, src[1]);
dest[2] = src[2];
dest[3] = src[3];
src += 4;
dest += 4;
}
break;
case CURVE_BLUE:
while (samples--)
{
dest[0] = src[0];
dest[1] = src[1];
dest[2] = pika_curve_map_value_inline (curve_blue, src[2]);
dest[3] = src[3];
src += 4;
dest += 4;
}
break;
case CURVE_ALPHA:
while (samples--)
{
dest[0] = src[0];
dest[1] = src[1];
dest[2] = src[2];
dest[3] = pika_curve_map_value_inline (curve_alpha, src[3]);
src += 4;
dest += 4;
}
break;
case (CURVE_RED | CURVE_GREEN | CURVE_BLUE):
while (samples--)
{
dest[0] = pika_curve_map_value_inline (curve_red, src[0]);
dest[1] = pika_curve_map_value_inline (curve_green, src[1]);
dest[2] = pika_curve_map_value_inline (curve_blue, src[2]);
dest[3] = src[3];
src += 4;
dest += 4;
}
break;
default:
while (samples--)
{
dest[0] = pika_curve_map_value_inline (curve_colors,
pika_curve_map_value_inline (curve_red,
src[0]));
dest[1] = pika_curve_map_value_inline (curve_colors,
pika_curve_map_value_inline (curve_green,
src[1]));
dest[2] = pika_curve_map_value_inline (curve_colors,
pika_curve_map_value_inline (curve_blue,
src[2]));
/* don't apply the colors curve to the alpha channel */
dest[3] = pika_curve_map_value_inline (curve_alpha, src[3]);
src += 4;
dest += 4;
}
break;
}
}
static guint
pika_curve_get_apply_mask (PikaCurve *curve_colors,
PikaCurve *curve_red,
PikaCurve *curve_green,
PikaCurve *curve_blue,
PikaCurve *curve_alpha)
{
return ((pika_curve_is_identity (curve_colors) ? 0 : CURVE_COLORS) |
(pika_curve_is_identity (curve_red) ? 0 : CURVE_RED) |
(pika_curve_is_identity (curve_green) ? 0 : CURVE_GREEN) |
(pika_curve_is_identity (curve_blue) ? 0 : CURVE_BLUE) |
(pika_curve_is_identity (curve_alpha) ? 0 : CURVE_ALPHA));
}
static inline gdouble
pika_curve_map_value_inline (PikaCurve *curve,
gdouble value)
{
if (curve->identity)
{
if (isfinite (value))
return CLAMP (value, 0.0, 1.0);
return 0.0;
}
/* check for known values first, so broken values like NaN
* delivered by broken drivers don't run into the interpolation
* code
*/
if (value > 0.0 && value < 1.0) /* interpolate the curve */
{
gdouble f;
gint index;
/* map value to the sample space */
value = value * (curve->n_samples - 1);
/* determine the indices of the closest sample points */
index = (gint) value;
/* calculate the position between the sample points */
f = value - index;
return (1.0 - f) * curve->samples[index] + f * curve->samples[index + 1];
}
else if (value >= 1.0)
{
return curve->samples[curve->n_samples - 1];
}
else
{
return curve->samples[0];
}
}