diff options
author | Benjamin Otte <otte@redhat.com> | 2012-11-08 15:26:33 +0100 |
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committer | Benjamin Otte <otte@redhat.com> | 2012-11-08 23:34:05 +0100 |
commit | e063a0fdf13a09ca44588862d6b0b4f04232759f (patch) | |
tree | 69c88ef57b6c2d4eeaa383d6ab62afcb03532ab3 /gtk/gtkhsla.c | |
parent | cff4718e9189969191e4dab5062bea4a8ad52d45 (diff) | |
download | gtk+-e063a0fdf13a09ca44588862d6b0b4f04232759f.tar.gz |
symboliccolor: Split out HSLA code
Diffstat (limited to 'gtk/gtkhsla.c')
-rw-r--r-- | gtk/gtkhsla.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/gtk/gtkhsla.c b/gtk/gtkhsla.c new file mode 100644 index 0000000000..a78849789d --- /dev/null +++ b/gtk/gtkhsla.c @@ -0,0 +1,185 @@ +/* GTK - The GIMP Toolkit + * Copyright (C) 2012 Benjamin Otte <otte@gnome.org> + * + * 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 + * Lesser 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 <http://www.gnu.org/licenses/>. + */ + +#include "config.h" + +#include "gtkhslaprivate.h" + +#include <math.h> + +void +_gtk_hsla_init (GtkHSLA *hsla, + double hue, + double saturation, + double lightness, + double alpha) +{ + g_return_if_fail (hsla != NULL); + + if (hue >= 0) + hsla->hue = fmod (hue, 360); + else + hsla->hue = fmod (hue, 360) + 360; + hsla->saturation = CLAMP (saturation, 0, 1); + hsla->lightness = CLAMP (lightness, 0, 1); + hsla->alpha = CLAMP (alpha, 0, 1); +} + +void +_gtk_hsla_init_from_rgba (GtkHSLA *hsla, + const GdkRGBA *rgba) +{ + gdouble min; + gdouble max; + gdouble red; + gdouble green; + gdouble blue; + gdouble 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 GtkHSLA *hsla) +{ + gdouble hue; + gdouble lightness; + gdouble saturation; + gdouble 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; + } +} + |