What has changed is this: the method signature (return type) of computeVertices() is now returning the more generic List instead of ArrayList. List is only an interface and ArrayList one of its concrete implementations. Toxiclibs is making full use of OOP and the Java 5 syntax which was not available in older versions of Processing prior to 1.2. The <Vec3D> after the List tells the compiler that this list can only store Vec3D's and no other types. This extra bit of information simplifies a lot of other code dealing with such lists and also makes that code faster & more safe.

E.g. the old example code (after computeVertices()) continued like this:

1. beginShape();
2. for(Iterator i=vertices.iterator(); i.hasNext(); ) {
3.   Vec3D v=(Vec3D)i.next();
4.   vertex(v.x,v.y);
5. }
6. endShape();

Because both the "vertices" ArrayList and the Iterator going over it were still untyped, you needed to cast each list item back to Vec3D (clunky & unnecessary). With the new syntax you can just write:

1. List<Vec3D> vertices = spline.computeVertices(8);
2. beginShape();
3. for(Vec3D v : vertices) {
4.   vertex(v.x,v.y);
5. }
6. endShape();

Hope that clarifies things!