gimp/libgimpcolor/gimprgb.c

337 lines
6.8 KiB
C

/* LIBGIMP - The GIMP Library
* Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
*
* This library 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 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include <glib.h>
#include "libgimpmath/gimpmath.h"
#include "gimpcolortypes.h"
#include "gimprgb.h"
/* RGB functions */
void
gimp_rgb_set (GimpRGB *rgb,
gdouble r,
gdouble g,
gdouble b)
{
g_return_if_fail (rgb != NULL);
rgb->r = r;
rgb->g = g;
rgb->b = b;
}
void
gimp_rgb_set_alpha (GimpRGB *rgb,
gdouble a)
{
g_return_if_fail (rgb != NULL);
rgb->a = a;
}
void
gimp_rgb_set_uchar (GimpRGB *rgb,
guchar r,
guchar g,
guchar b)
{
g_return_if_fail (rgb != NULL);
rgb->r = (gdouble) r / 255.0;
rgb->g = (gdouble) g / 255.0;
rgb->b = (gdouble) b / 255.0;
}
void
gimp_rgb_get_uchar (const GimpRGB *rgb,
guchar *r,
guchar *g,
guchar *b)
{
g_return_if_fail (rgb != NULL);
if (r) *r = ROUND (CLAMP (rgb->r, 0.0, 1.0) * 255.0);
if (g) *g = ROUND (CLAMP (rgb->g, 0.0, 1.0) * 255.0);
if (b) *b = ROUND (CLAMP (rgb->b, 0.0, 1.0) * 255.0);
}
void
gimp_rgb_add (GimpRGB *rgb1,
const GimpRGB *rgb2)
{
g_return_if_fail (rgb1 != NULL);
g_return_if_fail (rgb2 != NULL);
rgb1->r += rgb2->r;
rgb1->g += rgb2->g;
rgb1->b += rgb2->b;
}
void
gimp_rgb_subtract (GimpRGB *rgb1,
const GimpRGB *rgb2)
{
g_return_if_fail (rgb1 != NULL);
g_return_if_fail (rgb2 != NULL);
rgb1->r -= rgb2->r;
rgb1->g -= rgb2->g;
rgb1->b -= rgb2->b;
}
void
gimp_rgb_multiply (GimpRGB *rgb,
gdouble factor)
{
g_return_if_fail (rgb != NULL);
rgb->r *= factor;
rgb->g *= factor;
rgb->b *= factor;
}
gdouble
gimp_rgb_distance (const GimpRGB *rgb1,
const GimpRGB *rgb2)
{
g_return_val_if_fail (rgb1 != NULL, 0.0);
g_return_val_if_fail (rgb2 != NULL, 0.0);
return (fabs (rgb1->r - rgb2->r) +
fabs (rgb1->g - rgb2->g) +
fabs (rgb1->b - rgb2->b));
}
gdouble
gimp_rgb_max (const GimpRGB *rgb)
{
g_return_val_if_fail (rgb != NULL, 0.0);
if (rgb->r > rgb->g)
return (rgb->r > rgb->b) ? rgb->r : rgb->b;
return (rgb->g > rgb->b) ? rgb->g : rgb->b;
}
gdouble
gimp_rgb_min (const GimpRGB *rgb)
{
g_return_val_if_fail (rgb != NULL, 0.0);
if (rgb->r < rgb->g)
return (rgb->r < rgb->b) ? rgb->r : rgb->b;
return (rgb->g < rgb->b) ? rgb->g : rgb->b;
}
void
gimp_rgb_clamp (GimpRGB *rgb)
{
g_return_if_fail (rgb != NULL);
rgb->r = CLAMP (rgb->r, 0.0, 1.0);
rgb->g = CLAMP (rgb->g, 0.0, 1.0);
rgb->b = CLAMP (rgb->b, 0.0, 1.0);
rgb->a = CLAMP (rgb->a, 0.0, 1.0);
}
void
gimp_rgb_gamma (GimpRGB *rgb,
gdouble gamma)
{
gdouble ig;
g_return_if_fail (rgb != NULL);
if (gamma != 0.0)
ig = 1.0 / gamma;
else
ig = 0.0;
rgb->r = pow (rgb->r, ig);
rgb->g = pow (rgb->g, ig);
rgb->b = pow (rgb->b, ig);
}
gdouble
gimp_rgb_intensity (const GimpRGB *rgb)
{
gdouble intensity;
g_return_val_if_fail (rgb != NULL, 0.0);
intensity = GIMP_RGB_INTENSITY (rgb->r, rgb->g, rgb->b);
return CLAMP (intensity, 0.0, 1.0);
}
guchar
gimp_rgb_intensity_uchar (const GimpRGB *rgb)
{
g_return_val_if_fail (rgb != NULL, 0);
return ROUND (gimp_rgb_intensity (rgb) * 255.0);
}
void
gimp_rgb_composite (GimpRGB *color1,
const GimpRGB *color2,
GimpRGBCompositeMode mode)
{
gdouble factor;
g_return_if_fail (color1 != NULL);
g_return_if_fail (color2 != NULL);
switch (mode)
{
case GIMP_RGB_COMPOSITE_NONE:
break;
case GIMP_RGB_COMPOSITE_NORMAL:
/* put color2 on top of color1 */
if (color2->a == 1.0)
{
*color1 = *color2;
}
else
{
factor = color1->a * (1.0 - color2->a);
color1->r = color1->r * factor + color2->r * color2->a;
color1->g = color1->g * factor + color2->g * color2->a;
color1->b = color1->b * factor + color2->b * color2->a;
color1->a = factor + color2->a;
}
break;
case GIMP_RGB_COMPOSITE_BEHIND:
/* put color2 below color1 */
if (color1->a < 1.0)
{
factor = color2->a * (1.0 - color1->a);
color1->r = color2->r * factor + color1->r * color1->a;
color1->g = color2->g * factor + color1->g * color1->a;
color1->b = color2->b * factor + color1->b * color1->a;
color1->a = factor + color1->a;
}
break;
}
}
/* RGBA functions */
void
gimp_rgba_set (GimpRGB *rgba,
gdouble r,
gdouble g,
gdouble b,
gdouble a)
{
g_return_if_fail (rgba != NULL);
rgba->r = r;
rgba->g = g;
rgba->b = b;
rgba->a = a;
}
void
gimp_rgba_set_uchar (GimpRGB *rgba,
guchar r,
guchar g,
guchar b,
guchar a)
{
g_return_if_fail (rgba != NULL);
rgba->r = (gdouble) r / 255.0;
rgba->g = (gdouble) g / 255.0;
rgba->b = (gdouble) b / 255.0;
rgba->a = (gdouble) a / 255.0;
}
void
gimp_rgba_get_uchar (const GimpRGB *rgba,
guchar *r,
guchar *g,
guchar *b,
guchar *a)
{
g_return_if_fail (rgba != NULL);
if (r) *r = ROUND (CLAMP (rgba->r, 0.0, 1.0) * 255.0);
if (g) *g = ROUND (CLAMP (rgba->g, 0.0, 1.0) * 255.0);
if (b) *b = ROUND (CLAMP (rgba->b, 0.0, 1.0) * 255.0);
if (a) *a = ROUND (CLAMP (rgba->a, 0.0, 1.0) * 255.0);
}
void
gimp_rgba_add (GimpRGB *rgba1,
const GimpRGB *rgba2)
{
g_return_if_fail (rgba1 != NULL);
g_return_if_fail (rgba2 != NULL);
rgba1->r += rgba2->r;
rgba1->g += rgba2->g;
rgba1->b += rgba2->b;
rgba1->a += rgba2->a;
}
void
gimp_rgba_subtract (GimpRGB *rgba1,
const GimpRGB *rgba2)
{
g_return_if_fail (rgba1 != NULL);
g_return_if_fail (rgba2 != NULL);
rgba1->r -= rgba2->r;
rgba1->g -= rgba2->g;
rgba1->b -= rgba2->b;
rgba1->a -= rgba2->a;
}
void
gimp_rgba_multiply (GimpRGB *rgba,
gdouble factor)
{
g_return_if_fail (rgba != NULL);
rgba->r *= factor;
rgba->g *= factor;
rgba->b *= factor;
rgba->a *= factor;
}
gdouble
gimp_rgba_distance (const GimpRGB *rgba1,
const GimpRGB *rgba2)
{
g_return_val_if_fail (rgba1 != NULL, 0.0);
g_return_val_if_fail (rgba2 != NULL, 0.0);
return (fabs (rgba1->r - rgba2->r) + fabs (rgba1->g - rgba2->g) +
fabs (rgba1->b - rgba2->b) + fabs (rgba1->a - rgba2->a));
}