From 29aa4cb79b5e03065042bdebce67327de3e289be Mon Sep 17 00:00:00 2001 From: =?utf8?q?Alexis=20Laferri=C3=A8re?= Date: Wed, 9 Sep 2015 19:55:57 -0400 Subject: [PATCH] lib/noise: move ImprovedNoise from the rosetta perlin noise example MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Alexis Laferrière --- examples/rosettacode/perlin_noise.nit | 64 +----------------------------- lib/noise.nit | 69 +++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+), 63 deletions(-) diff --git a/examples/rosettacode/perlin_noise.nit b/examples/rosettacode/perlin_noise.nit index 0733bbf..a5cd314 100644 --- a/examples/rosettacode/perlin_noise.nit +++ b/examples/rosettacode/perlin_noise.nit @@ -8,69 +8,7 @@ # See: module perlin_noise -redef universal Float - # Smoothened `self` - fun fade: Float do return self*self*self*(self*(self*6.0-15.0)+10.0) -end - -# Improved noise -class ImprovedNoise - # Permutations - var p: Array[Int] = [151,160,137,91,90,15, - 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, - 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, - 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, - 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, - 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, - 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, - 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, - 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, - 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, - 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, - 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, - 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180] - - # Noise value in [-1..1] at 3d coordinates `x, y, z` - fun noise(x, y, z: Float): Float - do - var xx = x.to_i & 255 - var yy = y.to_i & 255 - var zz = z.to_i & 255 - - x -= x.floor - y -= y.floor - z -= z.floor - - var u = x.fade - var v = y.fade - var w = z.fade - - var a = p[xx ] + yy - var aa = p[a ] + zz - var ab = p[a+1 ] + zz - var b = p[xx+1] + yy - var ba = p[b ] + zz - var bb = p[b+1 ] + zz - - return w.lerp(v.lerp(u.lerp(grad(p[aa ], x, y, z ), - grad(p[ba ], x-1.0, y, z )), - u.lerp(grad(p[ab ], x, y-1.0, z ), - grad(p[bb ], x-1.0, y-1.0, z ))), - v.lerp(u.lerp(grad(p[aa+1], x, y, z-1.0), - grad(p[ba+1], x-1.0, y, z-1.0)), - u.lerp(grad(p[ab+1], x, y-1.0, z-1.0), - grad(p[bb+1], x-1.0, y-1.0, z-1.0)))) - end - - # Value at a corner of the grid - fun grad(hash: Int, x, y, z: Float): Float - do - var h = hash & 15 - var u = if h < 8 then x else y - var v = if h < 4 then y else if h == 12 or h == 14 then x else z - return (if h.is_even then u else -u) + (if h & 2 == 0 then v else -v) - end -end +import noise var map = new ImprovedNoise print map.noise(3.14, 42.0, 7.0).to_precision(17) diff --git a/lib/noise.nit b/lib/noise.nit index ba09bc1..4e42820 100644 --- a/lib/noise.nit +++ b/lib/noise.nit @@ -359,3 +359,72 @@ redef universal Int return self & 0x3FFF_FFFF end end + +redef universal Float + # Smoothened `self`, used by `ImprovedNoise` + private fun fade: Float do return self*self*self*(self*(self*6.0-15.0)+10.0) +end + +# Direct translation of Ken Perlin's improved noise Java implementation +# +# This implementation differs from `PerlinNoise` on two main points. +# This noise is calculated for a 3D point, vs 2D in `PerlinNoise`. +# `PerlinNoise` is based off a customizable seed, while this noise has a static data source. +class ImprovedNoise + + # Permutations + private var p: Array[Int] = [151,160,137,91,90,15, + 131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23, + 190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33, + 88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166, + 77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244, + 102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196, + 135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123, + 5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42, + 223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9, + 129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228, + 251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107, + 49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254, + 138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180] + + # Noise value in [-1..1] at 3D coordinates `x, y, z` + fun noise(x, y, z: Float): Float + do + var xx = x.floor.to_i & 255 + var yy = y.floor.to_i & 255 + var zz = z.floor.to_i & 255 + + x -= x.floor + y -= y.floor + z -= z.floor + + var u = x.fade + var v = y.fade + var w = z.fade + + var a = p[xx ] + yy + var aa = p[a ] + zz + var ab = p[a+1 ] + zz + var b = p[xx+1] + yy + var ba = p[b ] + zz + var bb = p[b+1 ] + zz + + return w.lerp(v.lerp(u.lerp(grad(p[aa ], x, y, z ), + grad(p[ba ], x-1.0, y, z )), + u.lerp(grad(p[ab ], x, y-1.0, z ), + grad(p[bb ], x-1.0, y-1.0, z ))), + v.lerp(u.lerp(grad(p[aa+1], x, y, z-1.0), + grad(p[ba+1], x-1.0, y, z-1.0)), + u.lerp(grad(p[ab+1], x, y-1.0, z-1.0), + grad(p[bb+1], x-1.0, y-1.0, z-1.0)))) + end + + # Value at a corner of the grid + private fun grad(hash: Int, x, y, z: Float): Float + do + var h = hash & 15 + var u = if h < 8 then x else y + var v = if h < 4 then y else if h == 12 or h == 14 then x else z + return (if h.is_even then u else -u) + (if h & 2 == 0 then v else -v) + end +end -- 1.7.9.5