Perlin noise: Difference between revisions

</pre>

=={{header|Rust}}==

{{trans|Java}}

<lang rust>fn main() {

println!("{}", noise(3.14, 42.0, 7.0));

}

fn noise(x: f64, y: f64, z: f64) -> f64 {

let x0 = x.floor() as usize & 255;

let y0 = y.floor() as usize & 255;

let z0 = z.floor() as usize & 255;

let x = x - x.floor();

let y = y - y.floor();

let z = z - z.floor();

let u = fade(x);

let v = fade(y);

let w = fade(z);

let a = P[x0] + y0;

let aa = P[a] + z0;

let ab = P[a + 1] + z0;

let b = P[x0 + 1] + y0;

let ba = P[b] + z0;

let bb = P[b + 1] + z0;

return lerp(w,

lerp(v, lerp(u, grad(P[aa], x , y , z),

grad(P[ba], x-1.0, y , z)),

lerp(u, grad(P[ab], x , y-1.0, z),

grad(P[bb], x-1.0, y-1.0, z))),

lerp(v, lerp(u, grad(P[aa+1], x , y , z-1.0),

grad(P[ba+1], x-1.0, y , z-1.0)),

lerp(u, grad(P[ab+1], x , y-1.0, z-1.0),

grad(P[bb+1], x-1.0, y-1.0, z-1.0))));

}

fn fade(t: f64) -> f64 {

t * t * t * ( t * (t * 6.0 - 15.0) + 10.0)

}

fn lerp(t: f64, a: f64, b: f64) -> f64 {

a + t * (b - a)

}

fn grad(hash: usize, x: f64, y: f64, z: f64) -> f64 {

let h = hash & 15;

let u = if h < 8 { x } else { y };

let v = if h < 4 { y } else { if h == 12 || h == 14 { x } else { z } };

return if h&1 == 0 { u } else { -u } + if h&2 == 0 { v } else { -v };

}

static P: [usize; 512] = [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,

180,151,160,137,91,90,15,131,13,201,95,96,53,194,233,7,225,140,36,103,30,69

,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];</lang>

'''Output:'''

<pre>

0.13691995878400012