Gorgeous Haskell Mandelbrot (and Burning Ship) in Haskell for your Enjoyment

As usual it's slow. It could be made much faster by using a parallel map. That's an exercise for the reader. Also PPM is terrible for anything but writing to, it must be converted immediately.

	import Complex
	main = writeFile "mandelthing.ppm" $ imageMB 1000 3
	type Colour = [Int]
	type Image = [Colour]
	createPPM :: Int -> Int -> Image -> String
	createPPM w h i =
	concat ["P3 ", show w, " ", show h, " 255\n",
	unlines.map (unwords.map show) $ i]
	--Calculates a fractal pixel from an initial condition 0+0i
	mandelbrotPixel x y = mb (x:+y) (0:+0) 0
	mb c x iter
	| magnitude x > 2 = iter
	| iter >= 255 = 255
	| otherwise = mb c (c+q^2) (iter+1)
	where
	q = x -- Mandelbrot
	-- q = (abs.realPart $ x) :+ (abs.imagPart $ x) --Burning Ship
	argandPlane x0 x1 y0 y1 width height =
	[(x,y)| y<-[y1,(y1-dy)..y0], --traverse from
	x<-[x0,(x0+dx)..x1]] --top-left to bottom-right
	where
	dx = (x1 - x0)/(width-1)
	dy = (y1 - y0)/(height-1)
	drawPlane :: (a->b->c)->(c->Colour)->[(a,b)]->Image
	drawPlane function = -- takes a function ,a colour function and a plane
	map . (.uncurry function)
	--'s' is size, 'a' is aspect as in a:1
	imageMB s a = createPPM (a*s) s $
	drawPlane mandelbrotPixel (\x->[x,x,x]) $
	argandPlane (-2) 1 0 1 (fromIntegral a *s') s'
	where s' = fromIntegral s

view raw Mandelthing.hs hosted with ❤ by GitHub