1 2 3 4 5 6 7 8 9 10 module Mandel where 11 import Complex -- 1.3 12 import PortablePixmap 13 default () 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 mandel::(Num a) => a -> [a] 49 mandel c = infiniteMandel 50 where 51 infiniteMandel = c : (map (\z -> z*z +c) infiniteMandel) 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 whenDiverge:: Int -> Double -> Complex Double -> Int 89 whenDiverge limit radius c 90 = walkIt (take limit (mandel c)) 91 where 92 walkIt [] = 0 -- Converged 93 walkIt (x:xs) | diverge x radius = 0 -- Diverged 94 | otherwise = 1 + walkIt xs -- Keep walking 95 96 97 98 99 100 101 102 103 104 105 106 107 108 -- VERY IMPORTANT FUNCTION: sits in inner loop 109 110 diverge::Complex Double -> Double -> Bool 111 diverge cmplx radius = magnitude cmplx > radius 112 113 114 115 116 117 118 119 120 121 122 parallelMandel:: [Complex Double] -> Int -> Double -> [Int] 123 parallelMandel mat limit radius 124 = map (whenDiverge limit radius) mat 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 mandelset::Double -> -- Minimum X viewport 150 Double -> -- Minimum Y viewport 151 Double -> -- Maximum X viewport 152 Double -> -- maximum Y viewport 153 Integer -> -- Window width 154 Integer -> -- Window height 155 Int -> -- Window depth 156 PixMap -- result pixmap 157 mandelset x y x' y' screenX screenY lIMIT 158 = createPixmap screenX screenY lIMIT (map prettyRGB result) 159 where 160 161 162 163 164 165 166 167 168 windowToViewport s t 169 = ((x + (((coerce s) * (x' - x)) / (fromInteger screenX))) :+ 170 (y + (((coerce t) * (y' - y)) / (fromInteger screenY)))) 171 172 coerce::Integer -> Double 173 coerce s = encodeFloat (toInteger s) 0 174 175 176 177 178 result = parallelMandel 179 [windowToViewport s t | t <- [1..screenY] , s<-[1..screenX]] 180 lIMIT 181 ((max (x'-x) (y'-y)) / 2.0) 182 183 prettyRGB::Int -> (Int,Int,Int) 184 prettyRGB s = let t = (lIMIT - s) in (s,t,t) 185