public override void update (float t)
{
CCNode node = (CCNode)_target;
bool stackable = ccConfig.CC_ENABLE_STACKABLE_ACTIONS;
if(stackable){
Vector2 currentPos = node.position;
Vector2 diff = currentPos - _previousPos;
_startPos = _startPos + diff;
Vector2 newPos = _startPos + _positionDelta * t;
node.position = newPos;
_previousPos = newPos;
} else {
node.position = _startPos + _positionDelta * t;
}
}
}