Cubic bezier curve utility methods in JavaScript.

bezier-util.js

  function getPointOnCurve(v1, c1, c2, v2, t) {

    return {
      x: bezierPoint(t, v1.x, c1.x, c2.x, v2.x),
      y: bezierPoint(t, v1.y, c1.y, c2.y, v2.y)
    };

  }

  function bezierPoint(t, o1, c1, c2, e1) {

    var C1 = (e1 - (3.0 * c2) + (3.0 * c1) - o1);
    var C2 = ((3.0 * c2) - (6.0 * c1) + (3.0 * o1));
    var C3 = ((3.0 * c1) - (3.0 * o1));
    var C4 = (o1);

    return ((C1*t*t*t) + (C2*t*t) + (C3*t) + C4);
  }