gimp/libgimpcolor/gimprgb.c

337 lines
8.1 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 3 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, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <babl/babl.h>
#include <glib-object.h>
#include "libgimpmath/gimpmath.h"
#include "gimpcolortypes.h"
#include "gimprgb.h"
/**
* SECTION: gimprgb
* @title: GimpRGB
* @short_description: Definitions and Functions relating to RGB colors.
*
* Definitions and Functions relating to RGB colors.
**/
/*
* GIMP_TYPE_RGB
*/
static GimpRGB * gimp_rgb_copy (const GimpRGB *rgb);
G_DEFINE_BOXED_TYPE (GimpRGB, gimp_rgb, gimp_rgb_copy, g_free)
static GimpRGB *
gimp_rgb_copy (const GimpRGB *rgb)
{
return g_memdup2 (rgb, sizeof (GimpRGB));
}
/* RGB functions */
/**
* gimp_rgb_set:
* @rgb: a #GimpRGB struct
* @red: the red component
* @green: the green component
* @blue: the blue component
*
* Sets the red, green and blue components of @rgb and leaves the
* alpha component unchanged. The color values should be between 0.0
* and 1.0 but there is no check to enforce this and the values are
* set exactly as they are passed in.
**/
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;
}
/**
* gimp_rgb_set_alpha:
* @rgb: a #GimpRGB struct
* @alpha: the alpha component
*
* Sets the alpha component of @rgb and leaves the RGB components unchanged.
**/
void
gimp_rgb_set_alpha (GimpRGB *rgb,
gdouble a)
{
g_return_if_fail (rgb != NULL);
rgb->a = a;
}
/**
* gimp_rgb_set_uchar:
* @rgb: a #GimpRGB struct
* @red: the red component
* @green: the green component
* @blue: the blue component
*
* Sets the red, green and blue components of @rgb from 8bit values
* (0 to 255) and leaves the alpha component unchanged.
**/
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;
}
/**
* gimp_rgb_get_uchar:
* @rgb: a #GimpRGB struct
* @red: (out) (optional): Location for red component, or %NULL
* @green: (out) (optional): Location for green component, or %NULL
* @blue: (out) (optional): Location for blue component, or %NULL
*
* Writes the red, green, blue and alpha components of @rgb to the
* color components @red, @green and @blue.
*/
void
gimp_rgb_get_uchar (const GimpRGB *rgb,
guchar *red,
guchar *green,
guchar *blue)
{
g_return_if_fail (rgb != NULL);
if (red) *red = ROUND (CLAMP (rgb->r, 0.0, 1.0) * 255.0);
if (green) *green = ROUND (CLAMP (rgb->g, 0.0, 1.0) * 255.0);
if (blue) *blue = 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_multiply (GimpRGB *rgb,
gdouble factor)
{
g_return_if_fail (rgb != NULL);
rgb->r *= factor;
rgb->g *= factor;
rgb->b *= factor;
}
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;
else
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;
else
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_composite (GimpRGB *color1,
const GimpRGB *color2,
GimpRGBCompositeMode mode)
{
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
{
gdouble 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)
{
gdouble 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 */
/**
* gimp_rgba_set:
* @rgba: a #GimpRGB struct
* @red: the red component
* @green: the green component
* @blue: the blue component
* @alpha: the alpha component
*
* Sets the red, green, blue and alpha components of @rgb. The values
* should be between 0.0 and 1.0 but there is no check to enforce this
* and the values are set exactly as they are passed in.
**/
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;
}
/**
* gimp_rgba_set_uchar:
* @rgba: a #GimpRGB struct
* @red: the red component
* @green: the green component
* @blue: the blue component
* @alpha: the alpha component
*
* Sets the red, green, blue and alpha components of @rgba from 8bit
* values (0 to 255).
**/
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;
}
/**
* gimp_rgba_get_uchar:
* @rgba: a #GimpRGB struct
* @red: (out) (optional): Location for the red component
* @green: (out) (optional): Location for the green component
* @blue: (out) (optional): Location for the blue component
* @alpha: (out) (optional): Location for the alpha component
*
* Gets the 8bit red, green, blue and alpha components of @rgba.
**/
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);
}
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));
}