/* 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, float hue, float saturation, float lightness, float 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) { 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 GtkHSLA *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; } } void _gtk_hsla_shade (GtkHSLA *dest, const GtkHSLA *src, float factor) { g_return_if_fail (dest != NULL); g_return_if_fail (src != NULL); dest->hue = src->hue; dest->lightness = src->lightness * factor; dest->lightness = CLAMP (dest->lightness, 0.0, 1.0); dest->saturation = src->saturation * factor; dest->saturation = CLAMP (dest->saturation, 0.0, 1.0); dest->alpha = src->alpha; }