var Vector2 = require('../math/Vector2'); 
var ShiftPosition = function (items, x, y, direction, output){ 
if (direction === undefined) { 
direction = 0; 
} 
if (output === undefined) { 
output = new Vector2(); 
} 
var px; 
var py; 
if (_AN_Read_length('length', items) > 1) { 
var i; 
var cx; 
var cy; 
var cur; 
if (direction === 0) { 
var len = _AN_Read_length('length', items) - 1; 
px = items[len].x; 
py = items[len].y; 
for (i = len - 1; i >= 0; i-- ){ 
cur = items[i]; 
cx = cur.x; 
cy = cur.y; 
cur.x = px; 
cur.y = py; 
px = cx; 
py = cy; 
} 
items[len].x = x; 
items[len].y = y; 
} 
 else { 
px = items[0].x; 
py = items[0].y; 
for (i = 1; i < _AN_Read_length('length', items); i++ ){ 
cur = items[i]; 
cx = cur.x; 
cy = cur.y; 
cur.x = px; 
cur.y = py; 
px = cx; 
py = cy; 
} 
items[0].x = x; 
items[0].y = y; 
} 
} 
 else { 
px = items[0].x; 
py = items[0].y; 
items[0].x = x; 
items[0].y = y; 
} 
output.x = px; 
output.y = py; 
return output; 
} 
; 
module.exports = ShiftPosition;