ViewPanel.setVision Method
 Sets current vision of the viewPanel.
 
 
Parameters
- left
 - 
Type: Number
Percentage of the vision's left edge 0<=left<=1 
- top
 - 
Type: Number
Percentage of the vision's top edge 0<=top<=1  
- scale
 - 
Type: Number
Percentage of the vision's scale 
- scaleY
 - 
Type: Number - May be null
(Optional) Percentage of the vision's scale in Y axis, defaults to scale is not supplied.