filter twist_two(
     image in,
     int Spread: 1-1000 (1))


spread=Spread;
ss=t*(W+spread)-W/2;
se=ss-spread;
angle =pi/2+2*pi*(x-se)/spread;

if x>=se then
if x<ss then
     if sign(y)*y>Y*sign(sin(angle))*sin(angle) then
rgba:[0,0,0,0]
     else
ny=y/sin(angle);
in(xy:[x,ny])
     end
else
     in(xy:[x,y])
end
else
in(xy:[x,y])
end

end
