Greyscale bars/Display: Difference between revisions

And here's another clever and shorter solution:

<lang futurebasic>

void local fn BuildWindow

'~'1

CGRect r = {0,0,640,400}

long i, j, bars = 8

CGFloat gray, delta, y = 0.0, w = 80

window 1, @"Grayscale Bars", r

pen -1

for j = 1 to 4

delta = 1.0/(bars-1)

if ( j mod 2 ) then gray = 0.0 else gray = 1.0 : delta = -delta

r = fn CGRectMake( 0, y, w, 100 )

for i = 1 to bars

rect fill r, fn ColorWithWhite( gray, 1.0 )

r.origin.x += w

gray += delta

next

bars = bars << 1

y += 100 : w = w/2

next

end fn

fn BuildWindow

HandleEvents

</lang>