1 files changed, 48 insertions, 0 deletions
diff --git a/java/api/src/aurelienribon/tweenengine/equations/Sine.java b/java/api/src/aurelienribon/tweenengine/equations/Sine.java
new file mode 100755
index 0000000..a4aec5c
--- /dev/null
+++ b/java/api/src/aurelienribon/tweenengine/equations/Sine.java
@@ -0,0 +1,48 @@
+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 Sine extends TweenEquation {
+	private static final float PI = 3.14159265f;
+
+	public static final Sine IN = new Sine() {
+		@Override
+		public final float compute(float t) {
+			return (float) -Math.cos(t * (PI/2)) + 1;
+		}
+
+		@Override
+		public String toString() {
+			return "Sine.IN";
+		}
+	};
+
+	public static final Sine OUT = new Sine() {
+		@Override
+		public final float compute(float t) {
+			return (float) Math.sin(t * (PI/2));
+		}
+
+		@Override
+		public String toString() {
+			return "Sine.OUT";
+		}
+	};
+
+	public static final Sine INOUT = new Sine() {
+		@Override
+		public final float compute(float t) {
+			return -0.5f * ((float) Math.cos(PI*t) - 1);
+		}
+
+		@Override
+		public String toString() {
+			return "Sine.INOUT";
+		}
+	};
+}
+\ No newline at end of file