On Tue, Jul 28, 2009 at 3:04 PM, CK Kashyap
Hi Everyone, I managed to write up the line drawing function using the following links - http://www.cs.helsinki.fi/group/goa/mallinnus/lines/bresenh.html http://rosettacode.org/wiki/Bresenham%27s_line_algorithm#Haskell
I tried to simplify your function a little bit : line :: Point -> Point -> [Point] line pa@(xa,ya) pb@(xb,yb) = map maySwitch . unfoldr go $ (x1,y1,0) where steep = abs (yb - ya) > abs (xb - xa) maySwitch = if steep then (\(x,y) -> (y,x)) else id [(x1,y1),(x2,y2)] = sort [maySwitch pa, maySwitch pb] deltax = x2 - x1 deltay = abs (y2 - y1) ystep = if y1 < y2 then 1 else -1 go (xTemp, yTemp, error) | xTemp > x2 = Nothing | otherwise = Just ((xTemp, yTemp), (xTemp + 1, newY, newError)) where tempError = error + deltay (newY, newError) = if (2*tempError) >= deltax then (yTemp+ystep,tempError-deltax) else (yTemp,tempError) I think it will be a bit better, tell me what you think ? -- Jedaï