--- a/artifacts/src/main/java/org/dive4elements/river/java2d/ShapeUtils.java	Tue Sep 25 16:43:51 2018 +0200
+++ b/artifacts/src/main/java/org/dive4elements/river/java2d/ShapeUtils.java	Wed Sep 26 15:48:05 2018 +0200
@@ -8,6 +8,7 @@
 
 package org.dive4elements.river.java2d;
 
+import java.awt.Color;
 import java.awt.Shape;
 import java.awt.geom.Area;
 import java.awt.geom.Ellipse2D;
@@ -24,7 +25,7 @@
 
     private static Map<Long, Shape> scaledShapesCache = new HashMap<>();
 
-    private static final Shape createCross(float size) {
+    private static final Shape createCross(final float size) {
 
         final GeneralPath p = new GeneralPath();
 
@@ -38,15 +39,15 @@
         return p;
     }
 
-    private static Shape createBox(float size) {
+    private static Shape createBox(final float size) {
         return new Rectangle2D.Double(-size, -size, size * 2, size * 2);
     }
 
-    private static Shape createCircle(float size) {
+    private static Shape createCircle(final float size) {
         return new Ellipse2D.Float(-size, -size, size * 2, size * 2);
     }
 
-    private static final Shape createTriangle(float size) {
+    private static final Shape createTriangle(final float size) {
         final GeneralPath p = new GeneralPath();
 
         p.moveTo(-size, size);
@@ -57,7 +58,7 @@
         return new Area(p);
     }
 
-    public static synchronized Shape getScaledShape(final ShapeType type, float size) {
+    public static synchronized Shape getScaledShape(final ShapeType type, final float size) {
 
         final Long hash = Long.valueOf((((long) type.ordinal()) << 32) | Float.floatToIntBits(size));
 
@@ -70,7 +71,7 @@
         return newShape;
     }
 
-    private static Shape createScaledShape(ShapeType type, float size) {
+    private static Shape createScaledShape(final ShapeType type, final float size) {
         switch (type) {
         case measured:
             return createBox(size);
@@ -86,4 +87,12 @@
             return createCircle(size);
         }
     }
+
+    public static Color withAlpha(final Color color, final int transparencyPercent) {
+
+        if (transparencyPercent <= 0 || transparencyPercent > 100 || color == null)
+            return color;
+
+        return new Color(color.getRed(), color.getGreen(), color.getBlue(), (int) ((100 - transparencyPercent) * 2.55f));
+    }
 }
\ No newline at end of file