add noise
This commit is contained in:
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8604db96b3
commit
8240361ffa
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@ -0,0 +1,248 @@
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#lang typed/racket
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; Copyright (c) 2013 John-Paul Verkamp
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; Direct translation of:
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; http://webstaff.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf
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(provide
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perlin
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simplex)
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(: grad3 (Vectorof (Vector Float Float Float)))
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(define grad3
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'#(#( 1.0 1.0 0.0) #(-1.0 1.0 0.0) #( 1.0 -1.0 0.0) #(-1.0 -1.0 0.0)
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#( 1.0 0.0 1.0) #(-1.0 0.0 1.0) #( 1.0 0.0 -1.0) #(-1.0 0.0 -1.0)
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#( 0.0 1.0 1.0) #( 0.0 -1.0 1.0) #( 0.0 1.0 -1.0) #( 0.0 -1.0 -1.0)))
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(: p (Vectorof Byte))
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(define p
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'#(151 160 137 91 90 15 131 13 201 95 96 53 194 233 7
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225 140 36 103 30 69 142 8 99 37 240 21 10 23 190 6
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148 247 120 234 75 0 26 197 62 94 252 219 203 117 35
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11 32 57 177 33 88 237 149 56 87 174 20 125 136 171
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168 68 175 74 165 71 134 139 48 27 166 77 146 158
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231 83 111 229 122 60 211 133 230 220 105 92 41 55
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46 245 40 244 102 143 54 65 25 63 161 1 216 80 73
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209 76 132 187 208 89 18 169 200 196 135 130 116 188
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159 86 164 100 109 198 173 186 3 64 52 217 226 250
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124 123 5 202 38 147 118 126 255 82 85 212 207 206
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59 227 47 16 58 17 182 189 28 42 223 183 170 213 119
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248 152 2 44 154 163 70 221 153 101 155 167 43 172 9
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129 22 39 253 19 98 108 110 79 113 224 232 178 185
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112 104 218 246 97 228 251 34 242 193 238 210 144 12
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191 179 162 241 81 51 145 235 249 14 239 107 49 192
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214 31 181 199 106 157 184 84 204 176 115 121 50 45
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127 4 150 254 138 236 205 93 222 114 67 29 24 72 243
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141 128 195 78 66 215 61 156 180))
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; To remove the need for index wrapping, double the permutation table length
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(: perm (Vectorof Byte))
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(define perm (vector-append p p))
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; This method is a *lot* faster than using (int)Math.floor(x)
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; TODO: Not sure if this is actually true in Racket
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(: fast-floor (Float -> Integer))
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(define (fast-floor x)
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(exact-floor x))
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(: dot ((Vector Float Float Float) Float Float Float -> Float))
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(define (dot g x y z)
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(+ (* (vector-ref g 0) x)
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(* (vector-ref g 1) y)
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(* (vector-ref g 2) z)))
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(: mix (Float Float Float -> Float))
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(define (mix a b t)
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(+ (* (- 1.0 t) a) (* t b)))
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(: fade (Float -> Float))
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(define (fade t)
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(* t t t (+ (* t (- (* t 6.0) 15.0)) 10.0)))
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; Classic Perlin noise, 3D version
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(: perlin (case-> (Real -> Float)
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(Real Real -> Float)
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(Real Real Real -> Float)))
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(define (perlin x [y 0.0] [z 0.0])
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(perlin^ (real->double-flonum x)
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(real->double-flonum y)
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(real->double-flonum z)))
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(: perlin^ (Float Float Float -> Float))
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(define (perlin^ x y z)
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; Find unit grid cell containing point
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(: X Integer) (: Y Integer) (: Z Integer)
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(define X (fast-floor x))
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(define Y (fast-floor y))
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(define Z (fast-floor z))
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; Get relative xyz coordinates of point within that cell
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(set! x (- x X))
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(set! y (- y Y))
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(set! z (- z Z))
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; Wrap the integer cells at 255 (smaller integer period can be introduced here)
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(set! X (bitwise-and X 255))
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(set! Y (bitwise-and Y 255))
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(set! Z (bitwise-and Z 255))
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; Calculate a set of eight hashed gradient indices
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(: gi000 Integer) (: gi001 Integer) (: gi010 Integer) (: gi011 Integer)
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(: gi100 Integer) (: gi101 Integer) (: gi110 Integer) (: gi111 Integer)
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(define gi000 (remainder (vector-ref perm (+ X (vector-ref perm (+ Y (vector-ref perm Z))))) 12))
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(define gi001 (remainder (vector-ref perm (+ X (vector-ref perm (+ Y (vector-ref perm (+ Z 1)))))) 12))
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(define gi010 (remainder (vector-ref perm (+ X (vector-ref perm (+ Y 1 (vector-ref perm Z))))) 12))
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(define gi011 (remainder (vector-ref perm (+ X (vector-ref perm (+ Y 1 (vector-ref perm (+ Z 1)))))) 12))
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(define gi100 (remainder (vector-ref perm (+ X 1 (vector-ref perm (+ Y (vector-ref perm Z))))) 12))
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(define gi101 (remainder (vector-ref perm (+ X 1 (vector-ref perm (+ Y (vector-ref perm (+ Z 1)))))) 12))
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(define gi110 (remainder (vector-ref perm (+ X 1 (vector-ref perm (+ Y 1 (vector-ref perm Z))))) 12))
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(define gi111 (remainder (vector-ref perm (+ X 1 (vector-ref perm (+ Y 1 (vector-ref perm (+ Z 1)))))) 12))
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; Calculate noise contributions from each of the eight corners
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(: n000 Float) (: n001 Float) (: n010 Float) (: n011 Float)
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(: n100 Float) (: n101 Float) (: n110 Float) (: n111 Float)
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(define n000 (dot (vector-ref grad3 gi000) x y z))
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(define n100 (dot (vector-ref grad3 gi100) (- x 1) y z))
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(define n010 (dot (vector-ref grad3 gi010) x (- y 1) z))
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(define n110 (dot (vector-ref grad3 gi110) (- x 1) (- y 1) z))
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(define n001 (dot (vector-ref grad3 gi001) x y (- z 1)))
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(define n101 (dot (vector-ref grad3 gi101) (- x 1) y (- z 1)))
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(define n011 (dot (vector-ref grad3 gi011) x (- y 1) (- z 1)))
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(define n111 (dot (vector-ref grad3 gi111) (- x 1) (- y 1) (- z 1)))
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; Compute the fade curve value for each of x, y, z
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(: u Float) (: v Float) (: w Float)
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(define u (fade x))
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(define v (fade y))
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(define w (fade z))
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; Interpolate along x the contributions from each of the corners
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(: nx00 Float) (: nx01 Float) (: nx10 Float) (: nx11 Float)
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(define nx00 (mix n000 n100 u))
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(define nx01 (mix n001 n101 u))
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(define nx10 (mix n010 n110 u))
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(define nx11 (mix n011 n111 u))
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; Interpolate the four results along y
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(: nxy0 Float) (: nxy1 Float)
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(define nxy0 (mix nx00 nx10 v))
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(define nxy1 (mix nx01 nx11 v))
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; Interpolate the two last results along z
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(mix nxy0 nxy1 w))
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; 3D simplex noise
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(: F3 Float) (: G3 Float)
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(define F3 (/ 1.0 3.0)) ; Very nice and simple skew factor for 3D
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(define G3 (/ 1.0 6.0)) ; Very nice and simple unskew factor, too
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(: simplex (case-> (Real -> Float)
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(Real Real -> Float)
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(Real Real Real -> Float)))
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(define (simplex x [y 0.0] [z 0.0])
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(simplex^ (real->double-flonum x)
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(real->double-flonum y)
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(real->double-flonum z)))
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(: simplex^ (Float Float Float -> Float))
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(define (simplex^ xin yin zin)
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; Skew the input space to determine which simplex cell we're in
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(: s Float)
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(define s (* (real->double-flonum (+ xin yin zin)) F3))
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(: i Integer) (: j Integer) (: k Integer)
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(define i (fast-floor (+ xin s)))
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(define j (fast-floor (+ yin s)))
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(define k (fast-floor (+ zin s)))
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(: t Float)
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(define t (* (real->double-flonum (+ i j k)) G3))
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(: X0 Float) (: Y0 Float) (: Z0 Float)
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(: x0 Float) (: y0 Float) (: z0 Float)
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(define X0 (- i t)) ; Unskew the cell origin back to (x,y,z) space
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(define Y0 (- j t))
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(define Z0 (- k t))
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(define x0 (- xin X0)) ; The x,y,z distances from the cell origin
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(define y0 (- yin Y0))
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(define z0 (- zin Z0))
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; For the 3D case, the simplex shape is a slightly irregular tetrahedron.
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; Determine which simplex we are in.
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(: i1 Integer) (: j1 Integer) (: k1 Integer)
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(: i2 Integer) (: j2 Integer) (: k2 Integer)
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(define-values (i1 j1 k1 i2 j2 k2)
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(cond
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[(and (>= x0 y0) (>= y0 z0)) (values 1 0 0 1 1 0)] ; X Y Z order
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[(and (>= x0 y0) (>= x0 z0)) (values 1 0 0 1 0 1)] ; X Z Y order
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[(>= x0 y0) (values 0 0 1 1 0 1)] ; Z X Y order
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[(< y0 z0) (values 0 0 1 0 1 1)] ; Z Y X order
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[(< x0 z0) (values 0 1 0 0 1 1)] ; Y Z X order
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[else (values 0 1 0 1 1 0)])) ; Y X Z order
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; A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z),
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; a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and
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; a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z), where
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; c = 1/6.
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(: x1 Float) (: y1 Float) (: z1 Float)
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(: x2 Float) (: y2 Float) (: z2 Float)
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(: x3 Float) (: y3 Float) (: z3 Float)
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(define x1 (+ (- x0 i1) G3)) ; Offsets for second corner in (x,y,z) coords
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(define y1 (+ (- y0 j1) G3))
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(define z1 (+ (- z0 k1) G3))
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(define x2 (+ (- x0 i2) (* 2.0 G3))) ; Offsets for third corner in (x,y,z) coords
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(define y2 (+ (- y0 j2) (* 2.0 G3)))
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(define z2 (+ (- z0 k2) (* 2.0 G3)))
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(define x3 (+ (- x0 1.0) (* 3.0 G3))) ; Offsets for last corner in (x,y,z) coords
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(define y3 (+ (- y0 1.0) (* 3.0 G3)))
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(define z3 (+ (- z0 1.0) (* 3.0 G3)))
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; Work out the hashed gradient indices of the four simplex corners
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(: ii Integer) (: jj Integer) (: kk Integer)
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(define ii (bitwise-and i 255))
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(define jj (bitwise-and j 255))
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(define kk (bitwise-and k 255))
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(: gi0 Integer) (: gi1 Integer) (: gi2 Integer) (: gi3 Integer)
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(define gi0 (remainder (vector-ref perm (+ ii (vector-ref perm (+ jj (vector-ref perm kk))))) 12))
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(define gi1 (remainder (vector-ref perm (+ ii i1 (vector-ref perm (+ jj j1 (vector-ref perm (+ kk k1)))))) 12))
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(define gi2 (remainder (vector-ref perm (+ ii i2 (vector-ref perm (+ jj j2 (vector-ref perm (+ kk k2)))))) 12))
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(define gi3 (remainder (vector-ref perm (+ ii 1 (vector-ref perm (+ jj 1 (vector-ref perm (+ kk 1)))))) 12))
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; Calculate the contribution from the four corners
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(: t0 Float) (: n0 Float)
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(define t0 (- 0.5 (* x0 x0) (* y0 y0) (* z0 z0)))
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(define n0
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(if (< t0 0)
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0.0
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(let ([t0^2 (* t0 t0)])
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(* t0^2 t0^2 (dot (vector-ref grad3 gi0) x0 y0 z0)))))
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(: t1 Float) (: n1 Float)
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(define t1 (- 0.5 (* x1 x1) (* y1 y1) (* z1 z1)))
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(define n1
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(if (< t1 0)
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0.0
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(let ([t1^2 (* t1 t1)])
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(* t1^2 t1^2 (dot (vector-ref grad3 gi1) x1 y1 z1)))))
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(: t2 Float) (: n2 Float)
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(define t2 (- 0.5 (* x2 x2) (* y2 y2) (* z2 z2)))
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(define n2
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(if (< t2 0)
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0.0
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(let ([t2^2 (* t2 t2)])
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(* t2^2 t2^2 (dot (vector-ref grad3 gi2) x2 y2 z2)))))
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(: t3 Float) (: n3 Float)
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(define t3 (- 0.5 (* x3 x3) (* y3 y3) (* z3 z3)))
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(define n3
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(if (< t3 0)
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0.0
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(let ([t3^2 (* t3 t3)])
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(* t3^2 t3^2 (dot (vector-ref grad3 gi3) x3 y3 z3)))))
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; Add contributions from each corner to get the final noise value.
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; The result is scaled to stay just inside [-1,1]
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; NOTE: This scaling factor seems to work better than the given one
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; I'm not sure why
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(* 76.5 (+ n0 n1 n2 n3)))
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41
outrun.rkt
41
outrun.rkt
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@ -1,7 +1,8 @@
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#lang racket
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#lang racket
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(require pict3d
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(require pict3d
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pict3d/universe
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pict3d/universe
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"pict3d-lib.rkt")
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"pict3d-lib.rkt"
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"noise.rkt")
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(struct scene-state
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(struct scene-state
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(done? dx dy sun-dir)
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(done? dx dy sun-dir)
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@ -15,18 +16,31 @@
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#:specular 0.3
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#:specular 0.3
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#:roughness 0.5))
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#:roughness 0.5))
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(define (mesh)
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(define (mesh t)
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(with-color (rgba-hex "05ffa1")
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(let* ([lines
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(let* ([lines
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(for*/list ([i (in-range -10 10)]
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(for*/list ([i (in-range -10 10)]
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[j (in-range 0 10)])
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[j (in-range 0 10)])
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(with-color (rgba-hex "05ffa1")
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(move (cylinder (pos (- 0.1) (- 0.1) -5)
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(move (cylinder (pos (- 0.1) (- 0.1) -5)
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(pos 0.1 0.1 10))
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(pos 0.1 0.1 10))
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(dir i 0 j)))]
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(dir i 0 j))))]
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[lines-frozen (freeze (apply combine lines))])
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[lines-frozen (freeze (apply combine lines))]
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(combine lines-frozen
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[spheres (for*/list ([i (in-range -10 10)]
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(move (rotate-y lines-frozen 90)
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[j (in-range -1 10)])
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(dir -7 0 5))))))
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(with-color (rgba-hex "ff71ce" 0.8)
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(let ([x i]
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[z j]
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[y (scale-number
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(perlin (scale-number i -10 10 0 1)
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(scale-number j -1 10 0 1)
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(scale-number t 0 2000 0 1))
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0 1
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1 5)])
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(sphere (pos x y z) 0.2))))])
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(combine lines-frozen
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spheres
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(move (rotate-y lines-frozen 90)
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(dir -7 0 5)))))
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(define scene
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(define scene
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(rotate-y (cube (pos 0 0 0) 1) 30))
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(rotate-y (cube (pos 0 0 0) 1) 30))
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@ -40,8 +54,9 @@
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(combine (basis 'camera
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(combine (basis 'camera
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(point-at (pos 0 4 -6) origin))
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(point-at (pos 0 4 -6) origin))
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(make-sunlight (scene-state-sun-dir s))
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(make-sunlight (scene-state-sun-dir s))
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(mesh)
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(mesh t)
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(move-y (rotate-x scene (/ t 20)) 2)))
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;; (move-y (rotate-x scene (/ t 20)) 2)
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))
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(define (on-key s n t k)
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(define (on-key s n t k)
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(case k
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(case k
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@ -1,7 +1,7 @@
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#lang racket
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#lang racket
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(require pict3d)
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(require pict3d)
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(provide rgba-hex emitted-hex)
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(provide rgba-hex emitted-hex scale-number)
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(define (get-hex str)
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(define (get-hex str)
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(let*-values ([(num) (string->number str 16)]
|
(let*-values ([(num) (string->number str 16)]
|
||||||
|
|
@ -10,9 +10,12 @@
|
||||||
[(red green) (quotient/remainder num 256)])
|
[(red green) (quotient/remainder num 256)])
|
||||||
(list (scale-n red) (scale-n green) (scale-n blue))))
|
(list (scale-n red) (scale-n green) (scale-n blue))))
|
||||||
|
|
||||||
;; TODO: alpha
|
(define (rgba-hex str [alpha 1])
|
||||||
(define (rgba-hex str)
|
(apply rgba `(,@(get-hex str) ,alpha)))
|
||||||
(apply rgba (get-hex str)))
|
|
||||||
(define (emitted-hex str intensity)
|
(define (emitted-hex str intensity)
|
||||||
(apply emitted `(,@(get-hex str) ,intensity)))
|
(apply emitted `(,@(get-hex str) ,intensity)))
|
||||||
|
|
||||||
|
|
||||||
|
(define (scale-number s a1 a2 b1 b2)
|
||||||
|
(let ([a (- a2 a1)] [b (- b2 b1)])
|
||||||
|
(exact->inexact (+ b1 (/ (* (- s a1) b) a)))))
|
||||||
|
|
|
||||||
Loading…
Reference in New Issue