var buildShapeString = function (pathNodes, length, closed, mat) {
  if (length === 0) {
    return '';
  }
  var _o = pathNodes.o;
  var _i = pathNodes.i;
  var _v = pathNodes.v;
  var i,
    shapeString = ' M' + mat.applyToPointStringified(_v[0][0], _v[0][1]);
  for (i = 1; i < length; i += 1) {
    shapeString += ' C' + mat.applyToPointStringified(_o[i - 1][0], _o[i - 1][1]) + ' ' + mat.applyToPointStringified(_i[i][0], _i[i][1]) + ' ' + mat.applyToPointStringified(_v[i][0], _v[i][1]);
  }
  if (closed && length) {
    shapeString += ' C' + mat.applyToPointStringified(_o[i - 1][0], _o[i - 1][1]) + ' ' + mat.applyToPointStringified(_i[0][0], _i[0][1]) + ' ' + mat.applyToPointStringified(_v[0][0], _v[0][1]);
    shapeString += 'z';
  }
  return shapeString;
};
