updated catmull spline formulas, added THREE.ClosedSplineCurve3, added curve.needsUpdate and .__arcLengthDivisions flags

src/core/Spline.js

@@ -34,8 +34,8 @@ THREE.Spline = function ( points ) {
 
 		c[ 0 ] = intPoint === 0 ? intPoint : intPoint - 1;
 		c[ 1 ] = intPoint;
-		c[ 2 ] = intPoint > this.points.length - 2 ? intPoint : intPoint + 1;
-		c[ 3 ] = intPoint > this.points.length - 3 ? intPoint : intPoint + 2;
+		c[ 2 ] = intPoint  > points.length - 2 ? points.length -1 : intPoint + 1;
+		c[ 3 ] = intPoint  > points.length - 3 ? points.length -1 : intPoint + 2;
 
 		pa = this.points[ c[ 0 ] ];
 		pb = this.points[ c[ 1 ] ];

src/extras/core/Curve.js

@@ -23,6 +23,7 @@
  * THREE.QuadraticBezierCurve3
  * THREE.CubicBezierCurve3
  * THREE.SplineCurve3
+ * THREE.ClosedSplineCurve3
  *
  **/
 
@@ -103,15 +104,19 @@ THREE.Curve.prototype.getLength = function () {
 
 THREE.Curve.prototype.getLengths = function ( divisions ) {
 
-	if ( !divisions ) divisions = 200;
+	if ( !divisions ) divisions = (this.__arcLengthDivisions) ? (this.__arcLengthDivisions): 200;
 
-	if ( this.cacheArcLengths && ( this.cacheArcLengths.length == divisions + 1 ) ) {
+	if ( this.cacheArcLengths 
+		&& ( this.cacheArcLengths.length == divisions + 1 ) 
+		&& !this.needsUpdate) {
 
 		//console.log( "cached", this.cacheArcLengths );
 		return this.cacheArcLengths;
 
 	}
 
+	this.needsUpdate = false;
+
 	var cache = [];
 	var current, last = this.getPoint( 0 );
 	var p, sum = 0;
@@ -457,8 +462,8 @@ THREE.SplineCurve.prototype.getPoint = function ( t ) {
 
 	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;
+	c[ 2 ] = intPoint  > points.length - 2 ? points.length -1 : intPoint + 1;
+	c[ 3 ] = intPoint  > points.length - 3 ? points.length -1 : intPoint + 2;
 
 	v.x = THREE.Curve.Utils.interpolate( points[ c[ 0 ] ].x, points[ c[ 1 ] ].x, points[ c[ 2 ] ].x, points[ c[ 3 ] ].x, weight );
 	v.y = THREE.Curve.Utils.interpolate( points[ c[ 0 ] ].y, points[ c[ 1 ] ].y, points[ c[ 2 ] ].y, points[ c[ 3 ] ].y, weight );
@@ -706,8 +711,8 @@ THREE.SplineCurve3 = THREE.Curve.create(
 
 		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;
+		c[ 2 ] = intPoint  > points.length - 2 ? points.length -1 : intPoint + 1;
+		c[ 3 ] = intPoint  > points.length - 3 ? points.length -1 : intPoint + 2;
 
 		v.x = THREE.Curve.Utils.interpolate( points[ c[ 0 ] ].x, points[ c[ 1 ] ].x, points[ c[ 2 ] ].x, points[ c[ 3 ] ].x, weight );
 		v.y = THREE.Curve.Utils.interpolate( points[ c[ 0 ] ].y, points[ c[ 1 ] ].y, points[ c[ 2 ] ].y, points[ c[ 3 ] ].y, weight );
@@ -718,3 +723,43 @@ THREE.SplineCurve3 = THREE.Curve.create(
 	}
 
 );
+
+/**************************************************************
+ *	Closed Spline 3D curve
+ **************************************************************/
+
+
+THREE.ClosedSplineCurve3 = THREE.Curve.create(
+
+	function ( points /* array of Vector3 */) {
+
+		this.points = (points == undefined) ? [] : points;
+
+	},
+
+    function ( t ) {
+
+        var v = new THREE.Vector3();
+        var c = [];
+        var points = this.points, point, intPoint, weight;
+        point = ( points.length - 0 ) * t;
+            // This needs to be from 0-length +1
+
+        intPoint = Math.floor( point );
+        weight = point - intPoint;
+            
+        intPoint += intPoint > 0 ? 0 : ( Math.floor( Math.abs( intPoint ) / points.length ) + 1 ) * points.length;
+        c[ 0 ] = ( intPoint - 1 ) % points.length;
+        c[ 1 ] = ( intPoint ) % points.length;
+        c[ 2 ] = ( intPoint + 1 ) % points.length;
+        c[ 3 ] = ( intPoint + 2 ) % points.length;
+
+        v.x = THREE.Curve.Utils.interpolate( points[ c[ 0 ] ].x, points[ c[ 1 ] ].x, points[ c[ 2 ] ].x, points[ c[ 3 ] ].x, weight );
+        v.y = THREE.Curve.Utils.interpolate( points[ c[ 0 ] ].y, points[ c[ 1 ] ].y, points[ c[ 2 ] ].y, points[ c[ 3 ] ].y, weight );
+        v.z = THREE.Curve.Utils.interpolate( points[ c[ 0 ] ].z, points[ c[ 1 ] ].z, points[ c[ 2 ] ].z, points[ c[ 3 ] ].z, weight );
+        
+        return v;
+
+    }
+
+);