add Color.fade(color, alpha)

2013-09-28 20:59:44 +02:00 · 2013-09-28 20:59:44 +02:00 · 01d98cbcb7
commit 01d98cbcb7
parent 32d17cca18
1 changed files with 9 additions and 0 deletions
--- a/vtm/src/org/oscim/backend/canvas/Color.java
+++ b/vtm/src/org/oscim/backend/canvas/Color.java
@ -94,4 +94,13 @@ public class Color {
 		}
 		throw new IllegalArgumentException("Unknown color");
 	}
+
+	public static int fade(int color, double alpha) {
+		alpha *= ((color >>> 24) & 0xff);
+
+		return ((int) alpha) << 24
+		        | ((int) alpha * ((color >>> 16) & 0xff)) << 16
+		        | ((int) alpha * ((color >>> 8) & 0xff)) << 8
+		        | ((int) alpha * ((color) & 0xff));
+	}
 }