mirror of
https://gitlab.gnome.org/GNOME/gtk.git
synced 2024-12-27 14:10:30 +00:00
147 lines
2.9 KiB
C
147 lines
2.9 KiB
C
#include <gdk/gdk.h>
|
|
#include "hsla.h"
|
|
|
|
void
|
|
_gdk_hsla_init_from_rgba (GdkHSLA *hsla,
|
|
const GdkRGBA *rgba)
|
|
{
|
|
float min;
|
|
float max;
|
|
float red;
|
|
float green;
|
|
float blue;
|
|
float delta;
|
|
|
|
g_return_if_fail (hsla != NULL);
|
|
g_return_if_fail (rgba != NULL);
|
|
|
|
red = rgba->red;
|
|
green = rgba->green;
|
|
blue = rgba->blue;
|
|
|
|
if (red > green)
|
|
{
|
|
if (red > blue)
|
|
max = red;
|
|
else
|
|
max = blue;
|
|
|
|
if (green < blue)
|
|
min = green;
|
|
else
|
|
min = blue;
|
|
}
|
|
else
|
|
{
|
|
if (green > blue)
|
|
max = green;
|
|
else
|
|
max = blue;
|
|
|
|
if (red < blue)
|
|
min = red;
|
|
else
|
|
min = blue;
|
|
}
|
|
|
|
hsla->lightness = (max + min) / 2;
|
|
hsla->saturation = 0;
|
|
hsla->hue = 0;
|
|
hsla->alpha = rgba->alpha;
|
|
|
|
if (max != min)
|
|
{
|
|
if (hsla->lightness <= 0.5)
|
|
hsla->saturation = (max - min) / (max + min);
|
|
else
|
|
hsla->saturation = (max - min) / (2 - max - min);
|
|
|
|
delta = max -min;
|
|
if (red == max)
|
|
hsla->hue = (green - blue) / delta;
|
|
else if (green == max)
|
|
hsla->hue = 2 + (blue - red) / delta;
|
|
else if (blue == max)
|
|
hsla->hue = 4 + (red - green) / delta;
|
|
|
|
hsla->hue *= 60;
|
|
if (hsla->hue < 0.0)
|
|
hsla->hue += 360;
|
|
}
|
|
}
|
|
|
|
void
|
|
_gdk_rgba_init_from_hsla (GdkRGBA *rgba,
|
|
const GdkHSLA *hsla)
|
|
{
|
|
float hue;
|
|
float lightness;
|
|
float saturation;
|
|
float m1, m2;
|
|
|
|
lightness = hsla->lightness;
|
|
saturation = hsla->saturation;
|
|
|
|
if (lightness <= 0.5)
|
|
m2 = lightness * (1 + saturation);
|
|
else
|
|
m2 = lightness + saturation - lightness * saturation;
|
|
m1 = 2 * lightness - m2;
|
|
|
|
rgba->alpha = hsla->alpha;
|
|
|
|
if (saturation == 0)
|
|
{
|
|
rgba->red = lightness;
|
|
rgba->green = lightness;
|
|
rgba->blue = lightness;
|
|
}
|
|
else
|
|
{
|
|
hue = hsla->hue + 120;
|
|
while (hue > 360)
|
|
hue -= 360;
|
|
while (hue < 0)
|
|
hue += 360;
|
|
|
|
if (hue < 60)
|
|
rgba->red = m1 + (m2 - m1) * hue / 60;
|
|
else if (hue < 180)
|
|
rgba->red = m2;
|
|
else if (hue < 240)
|
|
rgba->red = m1 + (m2 - m1) * (240 - hue) / 60;
|
|
else
|
|
rgba->red = m1;
|
|
|
|
hue = hsla->hue;
|
|
while (hue > 360)
|
|
hue -= 360;
|
|
while (hue < 0)
|
|
hue += 360;
|
|
|
|
if (hue < 60)
|
|
rgba->green = m1 + (m2 - m1) * hue / 60;
|
|
else if (hue < 180)
|
|
rgba->green = m2;
|
|
else if (hue < 240)
|
|
rgba->green = m1 + (m2 - m1) * (240 - hue) / 60;
|
|
else
|
|
rgba->green = m1;
|
|
|
|
hue = hsla->hue - 120;
|
|
while (hue > 360)
|
|
hue -= 360;
|
|
while (hue < 0)
|
|
hue += 360;
|
|
|
|
if (hue < 60)
|
|
rgba->blue = m1 + (m2 - m1) * hue / 60;
|
|
else if (hue < 180)
|
|
rgba->blue = m2;
|
|
else if (hue < 240)
|
|
rgba->blue = m1 + (m2 - m1) * (240 - hue) / 60;
|
|
else
|
|
rgba->blue = m1;
|
|
}
|
|
}
|