Avoid division by zero

[kaka/cakelight.git] / src / kaka / cakelight / Color.java

diff --git a/src/kaka/cakelight/Color.java b/src/kaka/cakelight/Color.java
index 0756209..5ea98cd 100644 (file)
--- a/src/kaka/cakelight/Color.java
+++ b/src/kaka/cakelight/Color.java
@@ -1,6 +1,8 @@
 package kaka.cakelight;
 
 public class Color {
+    public static final Color BLACK = Color.rgb(0, 0, 0);
+
     private static int[] gammaCorrection = new int[256];
 
     public static void calculateGammaCorrection(double gamma) {
@@ -23,6 +25,11 @@ public class Color {
         return c;
     }
 
+    /**
+     * @param hue 0.0 - 1.0
+     * @param saturation 0.0 - 1.0
+     * @param value 0.0 - 1.0
+     */
     public static Color hsv(double hue, double saturation, double value) {
         double normalizedHue = hue - Math.floor(hue);
         int h = (int)(normalizedHue * 6);
@@ -42,6 +49,49 @@ public class Color {
         }
     }
 
+    public double[] toHSV() {
+        return toHSV(r / 255.0, g / 255.0, b / 255.0);
+    }
+
+    /**
+     * @return an array with hsv values ranging from 0.0 to 1.0
+     */
+    public static double[] toHSV(double r, double g, double b) {
+        double h, s, v;
+        double min = Math.min(Math.min(r, g), b);
+        double max = Math.max(Math.max(r, g), b);
+
+        if (max == 0) {
+            return new double[] {0, 0, 0};
+        }
+
+        // Value
+        v = max;
+
+        // Saturation
+        double delta = max - min;
+        s = delta / max;
+
+        // Hue
+        if (delta > 0) {
+            if (r == max) {
+                h = (g - b) / delta; // between yellow & magenta
+            } else if (g == max) {
+                h = 2 + (b - r) / delta; // between cyan & yellow
+            } else {
+                h = 4 + (r - g) / delta; // between magenta & cyan
+            }
+        } else {
+            h = 0;
+        }
+
+        h /= 6.0;
+        if (h < 0)
+            h += 1;
+
+        return new double[] {h, s, v};
+    }
+
     public int r() {
         return gammaCorrection[r];
     }
@@ -62,4 +112,9 @@ public class Color {
                 (int)(b * invertedValue + other.b * value)
         );
     }
+
+    @Override
+    public String toString() {
+        return "Color{r=" + r + ", g=" + g + ", b=" + b + "}";
+    }
 }