更新

WPFDark/Internals/ColorSpaceHelper.cs

@@ -0,0 +1,59 @@
+using System;
+
+using WPFDark.Internals;
+
+namespace WPFDark.Internals
+{
+    internal static class ColorSpaceHelper
+    {
+        internal static (double Hue, double Saturation, double Value) RgbToHsv(double red, double green, double blue)
+        {
+            var max = (red, green, blue).Max();
+            var min = (red, green, blue).Min();
+
+            var h = 0.0;
+            var s = 0.0;
+            var v = max;
+
+            if (NumberHelper.AreClose(max, min) == false)
+            {
+                if (NumberHelper.AreClose(max, red)) h = 60.0 / 360 * (green - blue) / (max - min);
+                else if (NumberHelper.AreClose(max, green)) h = 60.0 / 360 * (blue - red) / (max - min) + 120.0 / 360;
+                else if (NumberHelper.AreClose(max, blue)) h = 60.0 / 360 * (red - green) / (max - min) + 240.0 / 360;
+
+                s = (max - min) / max;
+            }
+
+            if (h < 0)
+                h += 1;
+
+            return (h, s, v);
+        }
+
+        internal static (double Red, double Green, double Blue) HsvToRgb(double hue, double saturation, double value)
+        {
+            var h = NumberHelper.AreClose(hue, 1) ? 0 : hue;
+            var s = saturation;
+            var v = value;
+
+            if (NumberHelper.AreCloseZero(s))
+                return (v, v, v);
+
+            var dh = Math.Floor(h / (60.0 / 360));
+            var p = v * (1 - s);
+            var q = v * (1 - s * (h / (60.0 / 360) - dh));
+            var t = v * (1 - s * (1 - (h / (60.0 / 360) - dh)));
+
+            return dh switch
+            {
+                0 => (v, t, p),
+                1 => (q, v, p),
+                2 => (p, v, t),
+                3 => (p, q, v),
+                4 => (t, p, v),
+                5 => (v, p, q),
+                _ => throw new Exception()
+            };
+        }
+    }
+}