1 files changed, 47 insertions, 0 deletions
diff --git a/java/api/src/aurelienribon/tweenengine/equations/Quart.java b/java/api/src/aurelienribon/tweenengine/equations/Quart.java
new file mode 100755
index 0000000..826eebb
--- /dev/null
+++ b/java/api/src/aurelienribon/tweenengine/equations/Quart.java
@@ -0,0 +1,47 @@
+package aurelienribon.tweenengine.equations;
+
+import aurelienribon.tweenengine.TweenEquation;
+
+/**
+ * Easing equation based on Robert Penner's work:
+ * http://robertpenner.com/easing/
+ * @author Aurelien Ribon | http://www.aurelienribon.com/
+ */
+public abstract class Quart extends TweenEquation {
+	public static final Quart IN = new Quart() {
+		@Override
+		public final float compute(float t) {
+			return t*t*t*t;
+		}
+
+		@Override
+		public String toString() {
+			return "Quart.IN";
+		}
+	};
+
+	public static final Quart OUT = new Quart() {
+		@Override
+		public final float compute(float t) {
+			return -((t-=1)*t*t*t - 1);
+		}
+
+		@Override
+		public String toString() {
+			return "Quart.OUT";
+		}
+	};
+
+	public static final Quart INOUT = new Quart() {
+		@Override
+		public final float compute(float t) {
+			if ((t*=2) < 1) return 0.5f*t*t*t*t;
+			return -0.5f * ((t-=2)*t*t*t - 2);
+		}
+
+		@Override
+		public String toString() {
+			return "Quart.INOUT";
+		}
+	};
+}
+\ No newline at end of file