code: function ( axis, startX, startY, endX, endY ) {
          var result = 'none';
  
          if ( axis == 'horizontal' ) {
              if ( startX > endX ) {
                  result = 'left';
              } else if ( startX < endX ) {
                  result = 'right';
              }
          } else {
              if ( startY > endY ) {
                  result = 'top';
              } else if ( startY < endY ) {
                  result = 'bottom';
              }
          }
  
          return result;
      }
docs: 제스츄어 방향 반환 (left, right, top, bottom, none)