From 78df6337d658b9ea3671db007c38cd481c64a10b Mon Sep 17 00:00:00 2001
From: alteredq <postfilter@gmail.com>
Date: Tue, 1 Mar 2011 17:32:00 +0100
Subject: [PATCH] Forgotted Spline.js

---
 src/core/Spline.js | 52 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 src/core/Spline.js

diff --git a/src/core/Spline.js b/src/core/Spline.js
new file mode 100644
index 00000000..47c03ea0
--- /dev/null
+++ b/src/core/Spline.js
@@ -0,0 +1,52 @@
+/**
+ * Spline from Tween.js, slightly optimized
+ * http://sole.github.com/tween.js/examples/05_spline.html
+ *
+ * @author mrdoob / http://mrdoob.com/
+ */
+ 
+THREE.Spline = function () {
+
+	var c = [], v3 = { x: 0, y: 0, z: 0 },
+	point, intPoint, weight, w2, w3,
+	pa, pb, pc, pd;
+
+	this.get2DPoint = function ( points, k ) {
+
+		point = ( points.length - 1 ) * k;
+		intPoint = Math.floor( point );
+		weight = point - intPoint;
+
+		c[ 0 ] = intPoint == 0 ? intPoint : intPoint - 1;
+		c[ 1 ] = intPoint;
+		c[ 2 ] = intPoint > points.length - 2 ? intPoint : intPoint + 1;
+		c[ 3 ] = intPoint > points.length - 3 ? intPoint : intPoint + 2;
+
+		pa = points[ c[ 0 ] ];
+		pb = points[ c[ 1 ] ];
+		pc = points[ c[ 2 ] ];
+		pd = points[ c[ 3 ] ];
+
+		w2 = weight * weight;
+		w3 = weight * w2;
+		
+		v3.x = interpolate( pa.x, pb.x, pc.x, pd.x, weight, w2, w3 );
+		v3.y = interpolate( pa.y, pb.y, pc.y, pd.y, weight, w2, w3 );
+		v3.z = interpolate( pa.z, pb.z, pc.z, pd.z, weight, w2, w3 );
+		
+		return v3;
+
+	}
+
+	// Catmull-Rom
+
+	function interpolate( p0, p1, p2, p3, t, t2, t3 ) {
+
+		var v0 = ( p2 - p0 ) * 0.5,
+			v1 = ( p3 - p1 ) * 0.5;
+
+		return ( 2 * ( p1 - p2 ) + v0 + v1 ) * t3 + ( - 3 * ( p1 - p2 ) - 2 * v0 - v1 ) * t2 + v0 * t + p1;
+
+	}
+
+};
\ No newline at end of file