1 files changed, 203 insertions, 0 deletions
diff --git a/mate-panel/libpanel-util/panel-color.c b/mate-panel/libpanel-util/panel-color.c
new file mode 100644
index 00000000..9ac198a8
--- /dev/null
+++ b/mate-panel/libpanel-util/panel-color.c
@@ -0,0 +1,203 @@
+#include "panel-color.h"
+
+#if GTK_CHECK_VERSION (3, 0, 0)
+/**
+ * rgb_to_hls:
+ * @r: on input, red; on output, hue
+ * @g: on input, green; on output, lightness
+ * @b: on input, blue; on output, saturation
+ *
+ * Converts a red/green/blue triplet to a hue/lightness/saturation triplet.
+ */
+static void
+rgb_to_hls (gdouble *r, gdouble *g, gdouble *b)
+{
+ gdouble min;
+ gdouble max;
+ gdouble red;
+ gdouble green;
+ gdouble blue;
+ gdouble h, l, s;
+ gdouble delta;
+
+ red = *r;
+ green = *g;
+ blue = *b;
+
+ 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;
+ }
+
+ l = (max + min) / 2;
+ s = 0;
+ h = 0;
+
+ if (max != min) {
+ if (l <= 0.5)
+ s = (max - min) / (max + min);
+ else
+ s = (max - min) / (2 - max - min);
+
+ delta = max -min;
+ if (red == max)
+ h = (green - blue) / delta;
+ else if (green == max)
+ h = 2 + (blue - red) / delta;
+ else if (blue == max)
+ h = 4 + (red - green) / delta;
+
+ h *= 60;
+ if (h < 0.0)
+ h += 360;
+ }
+
+ *r = h;
+ *g = l;
+ *b = s;
+}
+
+/**
+ * hls_to_rgb:
+ * @h: on input, hue; on output, red
+ * @l: on input, lightness; on output, green
+ * @s: on input, saturation; on output, blue
+ *
+ * Converts a hue/lightness/saturation triplet to a red/green/blue triplet.
+ */
+static void
+hls_to_rgb (gdouble *h, gdouble *l, gdouble *s)
+{
+ gdouble hue;
+ gdouble lightness;
+ gdouble saturation;
+ gdouble m1, m2;
+ gdouble r, g, b;
+
+ lightness = *l;
+ saturation = *s;
+
+ if (lightness <= 0.5)
+ m2 = lightness * (1 + saturation);
+ else
+ m2 = lightness + saturation - lightness * saturation;
+ m1 = 2 * lightness - m2;
+
+ if (saturation == 0) {
+ *h = lightness;
+ *l = lightness;
+ *s = lightness;
+ } else {
+ hue = *h + 120;
+ while (hue > 360)
+ hue -= 360;
+ while (hue < 0)
+ hue += 360;
+
+ if (hue < 60)
+ r = m1 + (m2 - m1) * hue / 60;
+ else if (hue < 180)
+ r = m2;
+ else if (hue < 240)
+ r = m1 + (m2 - m1) * (240 - hue) / 60;
+ else
+ r = m1;
+
+ hue = *h;
+ while (hue > 360)
+ hue -= 360;
+ while (hue < 0)
+ hue += 360;
+
+ if (hue < 60)
+ g = m1 + (m2 - m1) * hue / 60;
+ else if (hue < 180)
+ g = m2;
+ else if (hue < 240)
+ g = m1 + (m2 - m1) * (240 - hue) / 60;
+ else
+ g = m1;
+
+ hue = *h - 120;
+ while (hue > 360)
+ hue -= 360;
+ while (hue < 0)
+ hue += 360;
+
+ if (hue < 60)
+ b = m1 + (m2 - m1) * hue / 60;
+ else if (hue < 180)
+ b = m2;
+ else if (hue < 240)
+ b = m1 + (m2 - m1) * (240 - hue) / 60;
+ else
+ b = m1;
+
+ *h = r;
+ *l = g;
+ *s = b;
+ }
+}
+
+/**
+ * gtk_style_shade:
+ * @a: the starting colour
+ * @b: (out): the resulting colour
+ * @k: amount to scale lightness and saturation by
+ *
+ * Takes a colour "a", scales the lightness and saturation by a certain amount,
+ * and sets "b" to the resulting colour.
+ * gtkstyle.c cut-and-pastage.
+ */ 
+void
+gtk_style_shade (GdkRGBA *a, GdkRGBA *b, gdouble k)
+{
+ gdouble red;
+ gdouble green;
+ gdouble blue;
+
+ red = a->red;
+ green = a->green;
+ blue = a->blue;
+
+ rgb_to_hls (&red, &green, &blue);
+
+ green *= k;
+ if (green > 1.0)
+ green = 1.0;
+ else if (green < 0.0)
+ green = 0.0;
+
+ blue *= k;
+ if (blue > 1.0)
+ blue = 1.0;
+ else if (blue < 0.0)
+ blue = 0.0;
+
+ hls_to_rgb (&red, &green, &blue);
+
+ b->red = red;
+ b->green = green;
+ b->blue = blue;
+}
+#else
+
+#endif
+