' Verticle Zoom (Stretch)  
' ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ  
' cODED bY ßudda/NFA 
' StARtEd : 15/10/1995 
' FiNiSHed: 15/10/1995 

Load "scr_man.abk"

' --- demonstrational picture
Unpack 5 To 0
Screen Hide 0

' --- save details about screen
SH=Screen Height(0)
SW=Screen Width(0)
SC=Screen Colour
SM=Screen Mode

' --- variable variables!! try changing them 
SPEED=5
STRETCH=SH*4 : Rem stretched to twice it's original height! 

' --- open screen to see it all on 
Screen Open 1,SW,SH,SC,SM
Flash Off 
Curs Off 
Hide On 
Get Palette 0
Double Buffer 
Autoback 0

' --- actual stretch code (very small?!) 
For SCAN#=SH To STRETCH Step SPEED
   LIN#=SH/SCAN#
   OFFSET=(SH/2)-((SH/LIN#)/2)
   
   For YYY#=0 To SH Step(LIN#*SPEED)
      Screen Copy 0,0,YYY#,SW,YYY#+SPEED To 1,0,OFFSET
      Add OFFSET,SPEED
   Next YYY#
   
   Screen Swap 
   Wait Vbl 
Next SCAN#