@XYScaling
--track0:XScale,0,1000,100
--track1:YScale,0,1000,100
xscale=obj.track0
yscale=obj.track1
obj.zoom=math.max(xscale,yscale)/100
if(xscale>yscale) then
  obj.aspect=yscale/xscale-1
else
  obj.aspect=1-xscale/yscale
end