function getShapeEdgePoint(shapeObj) {
  return [
    shapeObj.getPointByOrigin('left', 'top'),
    shapeObj.getPointByOrigin('right', 'top'),
    shapeObj.getPointByOrigin('left', 'bottom'),
    shapeObj.getPointByOrigin('right', 'bottom'),
  ];
}
Shape edge points
@param {fabric.Object} shapeObj - Selected shape object on canvas
@returns {Array} shapeEdgePoint - shape edge positions