1 files changed, 39 insertions, 0 deletions
diff --git a/java/api/src/aurelienribon/tweenengine/paths/CatmullRom.java b/java/api/src/aurelienribon/tweenengine/paths/CatmullRom.java
new file mode 100755
index 0000000..5dedae4
--- /dev/null
+++ b/java/api/src/aurelienribon/tweenengine/paths/CatmullRom.java
@@ -0,0 +1,39 @@
+package aurelienribon.tweenengine.paths;
+
+import aurelienribon.tweenengine.TweenPath;
+
+/**
+ * @author Aurelien Ribon | http://www.aurelienribon.com/
+ */
+public class CatmullRom implements TweenPath {
+	@Override
+	public float compute(float t, float[] points, int pointsCnt) {
+		int segment = (int) Math.floor((pointsCnt-1) * t);
+		segment = Math.max(segment, 0);
+		segment = Math.min(segment, pointsCnt-2);
+
+		t = t * (pointsCnt-1) - segment;
+
+		if (segment == 0) {
+			return catmullRomSpline(points[0], points[0], points[1], points[2], t);
+		}
+
+		if (segment == pointsCnt-2) {
+			return catmullRomSpline(points[pointsCnt-3], points[pointsCnt-2], points[pointsCnt-1], points[pointsCnt-1], t);
+		}
+
+		return catmullRomSpline(points[segment-1], points[segment], points[segment+1], points[segment+2], t);
+	}
+
+	private float catmullRomSpline(float a, float b, float c, float d, float t) {
+		float t1 = (c - a) * 0.5f;
+		float t2 = (d - b) * 0.5f;
+
+		float h1 = +2 * t * t * t - 3 * t * t + 1;
+		float h2 = -2 * t * t * t + 3 * t * t;
+		float h3 = t * t * t - 2 * t * t + t;
+		float h4 = t * t * t - t * t;
+
+		return b * h1 + c * h2 + t1 * h3 + t2 * h4;
+	}
+}