// E.g., 9s (45%) 🠆 10s (50%)
  function diffText(from, to) {
    return percentText(from) + " 🠆 " + percentText(to);
  }

  // percentText returns text that displays v in appropriate units alongside its
  // percentange.
  function percentText(v) {
    function percent(v, total) {
      return Number(((100.0 * v) / total).toFixed(1)) + '%';
    }

  }

  function handleWheel(e) {
    if (e.deltaY == 0) return;
    // Change scale factor by 1.1 or 1/1.1
    rescale(currentScale * (e.deltaY < 0 ? 1.1 : (1/1.1)),
            toSvg(e.offsetX, e.offsetY));
  }

  function setMode(m) {
    mode = m;
    touchid = null;
    touchid2 = null;
  }

  function panStart(x, y) {
    moved = false;
    panLastX = x;

	return svgRoot;
}

/**
 * Instance an SVGPoint object with given event coordinates.
 */
function getEventPoint(evt) {
	var p = root.createSVGPoint();

	p.x = evt.clientX;
	p.y = evt.clientY;

	return p;
}

/**
 * Sets the current transform matrix of an element.
 */
function setCTM(element, matrix) {