225 lines
7.5 KiB
WebGPU Shading Language
225 lines
7.5 KiB
WebGPU Shading Language
#include "../math/mod289.wgsl"
|
|
#include "../math/permute.wgsl"
|
|
#include "../math/taylorInvSqrt.wgsl"
|
|
#include "../math/grad4.wgsl"
|
|
|
|
/*
|
|
contributors: [Stefan Gustavson, Ian McEwan]
|
|
description: Simplex Noise https://github.com/stegu/webgl-noise
|
|
use: snoise2/3/4(<vec2f|vec3f|vec4f> pos)
|
|
license: |
|
|
Copyright 2021-2023 by Stefan Gustavson and Ian McEwan.
|
|
Published under the terms of the MIT license:
|
|
https://opensource.org/license/mit/
|
|
*/
|
|
|
|
|
|
fn snoise2(v: vec2f) -> f32 {
|
|
let C = vec4(0.211324865405187, // (3.0-sqrt(3.0))/6.0
|
|
0.366025403784439, // 0.5*(sqrt(3.0)-1.0)
|
|
-0.577350269189626, // -1.0 + 2.0 * C.x
|
|
0.024390243902439); // 1.0 / 41.0
|
|
// First corner
|
|
var i = floor(v + dot(v, C.yy) );
|
|
let x0 = v - i + dot(i, C.xx);
|
|
|
|
// Other corners
|
|
//i1.x = step( x0.y, x0.x ); // x0.x > x0.y ? 1.0 : 0.0
|
|
//i1.y = 1.0 - i1.x;
|
|
let i1 = select(vec2(0.0, 1.0), vec2(1.0, 0.0), x0.x > x0.y);
|
|
// x0 = x0 - 0.0 + 0.0 * C.xx ;
|
|
// x1 = x0 - i1 + 1.0 * C.xx ;
|
|
// x2 = x0 - 1.0 + 2.0 * C.xx ;
|
|
let x12 = x0.xyxy + C.xxzz - vec4(i1, 0.0, 0.0);
|
|
|
|
// Permutations
|
|
i = mod289_2(i); // Avoid truncation effects in permutation
|
|
let p = permute3( permute3( i.y + vec3(0.0, i1.y, 1.0 )) + i.x + vec3(0.0, i1.x, 1.0 ));
|
|
|
|
var m = max(0.5 - vec3(dot(x0,x0), dot(x12.xy,x12.xy), dot(x12.zw,x12.zw)), vec3(0.0));
|
|
m = m*m;
|
|
m = m*m;
|
|
|
|
// Gradients: 41 points uniformly over a line, mapped onto a diamond.
|
|
// The ring size 17*17 = 289 is close to a multiple of 41 (41*7 = 287)
|
|
|
|
let x = 2.0 * fract(p * C.www) - 1.0;
|
|
let h = abs(x) - 0.5;
|
|
let ox = floor(x + 0.5);
|
|
let a0 = x - ox;
|
|
|
|
// Normalise gradients implicitly by scaling m
|
|
// Approximation of: m *= inversesqrt( a0*a0 + h*h );
|
|
m *= 1.79284291400159 - 0.85373472095314 * ( a0*a0 + h*h );
|
|
|
|
// Compute final noise value at P
|
|
let gx = a0.x * x0.x + h.x * x0.y;
|
|
let gyz = a0.yz * x12.xz + h.yz * x12.yw;
|
|
return 130.0 * dot(m, vec3(gx, gyz));
|
|
}
|
|
|
|
fn snoise3(v: vec3f) -> f32 {
|
|
let C = vec2(1.0/6.0, 1.0/3.0) ;
|
|
let D = vec4(0.0, 0.5, 1.0, 2.0);
|
|
|
|
// First corner
|
|
var i = floor(v + dot(v, C.yyy) );
|
|
let x0 = v - i + dot(i, C.xxx) ;
|
|
|
|
// Other corners
|
|
let g = step(x0.yzx, x0.xyz);
|
|
let l = 1.0 - g;
|
|
let i1 = min( g.xyz, l.zxy );
|
|
let i2 = max( g.xyz, l.zxy );
|
|
|
|
// x0 = x0 - 0.0 + 0.0 * C.xxx;
|
|
// x1 = x0 - i1 + 1.0 * C.xxx;
|
|
// x2 = x0 - i2 + 2.0 * C.xxx;
|
|
// x3 = x0 - 1.0 + 3.0 * C.xxx;
|
|
let x1 = x0 - i1 + C.xxx;
|
|
let x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
|
|
let x3 = x0 - D.yyy; // -1.0+3.0*C.x = -0.5 = -D.y
|
|
|
|
// Permutations
|
|
i = mod289_3(i);
|
|
let p = permute4( permute4( permute4(
|
|
i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
|
|
+ i.y + vec4(0.0, i1.y, i2.y, 1.0 ))
|
|
+ i.x + vec4(0.0, i1.x, i2.x, 1.0 ));
|
|
|
|
// Gradients: 7x7 points over a square, mapped onto an octahedron.
|
|
// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
|
|
let n_ = 0.142857142857; // 1.0/7.0
|
|
let ns = n_ * D.wyz - D.xzx;
|
|
|
|
let j = p - 49.0 * floor(p * ns.z * ns.z); // mod(p,7*7)
|
|
|
|
let x_ = floor(j * ns.z);
|
|
let y_ = floor(j - 7.0 * x_ ); // mod(j,N)
|
|
|
|
let x = x_ *ns.x + ns.yyyy;
|
|
let y = y_ *ns.x + ns.yyyy;
|
|
let h = 1.0 - abs(x) - abs(y);
|
|
|
|
let b0 = vec4( x.xy, y.xy );
|
|
let b1 = vec4( x.zw, y.zw );
|
|
|
|
//let s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
|
|
//let s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
|
|
let s0 = floor(b0)*2.0 + 1.0;
|
|
let s1 = floor(b1)*2.0 + 1.0;
|
|
let sh = -step(h, vec4(0.0));
|
|
|
|
let a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
|
|
let a1 = b1.xzyw + s1.xzyw*sh.zzww ;
|
|
|
|
var p0 = vec3(a0.xy,h.x);
|
|
var p1 = vec3(a0.zw,h.y);
|
|
var p2 = vec3(a1.xy,h.z);
|
|
var p3 = vec3(a1.zw,h.w);
|
|
|
|
//Normalise gradients
|
|
let norm = taylorInvSqrt4(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
|
|
p0 *= norm.x;
|
|
p1 *= norm.y;
|
|
p2 *= norm.z;
|
|
p3 *= norm.w;
|
|
|
|
// Mix final noise value
|
|
var m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), vec4(0.0));
|
|
m = m * m;
|
|
return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1),
|
|
dot(p2,x2), dot(p3,x3) ) );
|
|
}
|
|
|
|
fn snoise4(v: vec4f) -> f32 {
|
|
let C = vec4( 0.138196601125011, // (5 - sqrt(5))/20 G4
|
|
0.276393202250021, // 2 * G4
|
|
0.414589803375032, // 3 * G4
|
|
-0.447213595499958); // -1 + 4 * G4
|
|
|
|
// First corner
|
|
var i = floor(v + dot(v, vec4(.309016994374947451)) ); // (sqrt(5) - 1)/4
|
|
let x0 = v - i + dot(i, C.xxxx);
|
|
|
|
// Other corners
|
|
|
|
// Rank sorting originally contributed by Bill Licea-Kane, AMD (formerly ATI)
|
|
let isX = step( x0.yzw, x0.xxx );
|
|
let isYZ = step( x0.zww, x0.yyz );
|
|
// i0.x = dot( isX, vec3( 1.0 ) );
|
|
var i0 = vec4(isX.x + isX.y + isX.z, 1.0 - isX);
|
|
// i0.y += dot( isYZ.xy, vec2( 1.0 ) );
|
|
i0 += vec4(0.0, isYZ.x + isYZ.y, 1.0 - isYZ.xy);
|
|
i0 += vec4(0.0, 0.0, isYZ.z, 1.0 - isYZ.z);
|
|
|
|
// i0 now contains the unique values 0,1,2,3 in each channel
|
|
let i3 = clamp( i0, vec4(0.0), vec4(1.0) );
|
|
let i2 = clamp( i0 - 1.0, vec4(0.0), vec4(1.0) );
|
|
let i1 = clamp( i0 - 2.0, vec4(0.0), vec4(1.0) );
|
|
|
|
// x0 = x0 - 0.0 + 0.0 * C.xxxx
|
|
// x1 = x0 - i1 + 1.0 * C.xxxx
|
|
// x2 = x0 - i2 + 2.0 * C.xxxx
|
|
// x3 = x0 - i3 + 3.0 * C.xxxx
|
|
// x4 = x0 - 1.0 + 4.0 * C.xxxx
|
|
let x1 = x0 - i1 + C.xxxx;
|
|
let x2 = x0 - i2 + C.yyyy;
|
|
let x3 = x0 - i3 + C.zzzz;
|
|
let x4 = x0 + C.wwww;
|
|
|
|
// Permutations
|
|
i = mod289_4(i);
|
|
let j0 = permute( permute( permute( permute(i.w) + i.z) + i.y) + i.x);
|
|
let j1 = permute4( permute4( permute4( permute4 (
|
|
i.w + vec4(i1.w, i2.w, i3.w, 1.0 ))
|
|
+ i.z + vec4(i1.z, i2.z, i3.z, 1.0 ))
|
|
+ i.y + vec4(i1.y, i2.y, i3.y, 1.0 ))
|
|
+ i.x + vec4(i1.x, i2.x, i3.x, 1.0 ));
|
|
|
|
// Gradients: 7x7x6 points over a cube, mapped onto a 4-cross polytope
|
|
// 7*7*6 = 294, which is close to the ring size 17*17 = 289.
|
|
let ip = vec4(1.0/294.0, 1.0/49.0, 1.0/7.0, 0.0) ;
|
|
|
|
var p0 = grad4(j0, ip);
|
|
var p1 = grad4(j1.x, ip);
|
|
var p2 = grad4(j1.y, ip);
|
|
var p3 = grad4(j1.z, ip);
|
|
var p4 = grad4(j1.w, ip);
|
|
|
|
// Normalise gradients
|
|
let norm = taylorInvSqrt4(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
|
|
p0 *= norm.x;
|
|
p1 *= norm.y;
|
|
p2 *= norm.z;
|
|
p3 *= norm.w;
|
|
p4 *= taylorInvSqrt(dot(p4,p4));
|
|
|
|
// Mix contributions from the five corners
|
|
var m0 = max(0.6 - vec3(dot(x0,x0), dot(x1,x1), dot(x2,x2)), vec3(0.0));
|
|
var m1 = max(0.6 - vec2(dot(x3,x3), dot(x4,x4) ), vec2(0.0));
|
|
m0 = m0 * m0;
|
|
m1 = m1 * m1;
|
|
return 49.0 * ( dot(m0*m0, vec3( dot( p0, x0 ), dot( p1, x1 ), dot( p2, x2 )))
|
|
+ dot(m1*m1, vec2( dot( p3, x3 ), dot( p4, x4 ) ) ) ) ;
|
|
}
|
|
|
|
fn snoise22(x: vec2f) -> vec2f {
|
|
let s = snoise2(vec2( x ));
|
|
let s1 = snoise2(vec2( x.y - 19.1, x.x + 47.2 ));
|
|
return vec2( s , s1 );
|
|
}
|
|
|
|
fn snoise33(x: vec3f) -> vec3f {
|
|
let s = snoise3(vec3( x ));
|
|
let s1 = snoise3(vec3( x.y - 19.1 , x.z + 33.4 , x.x + 47.2 ));
|
|
let s2 = snoise3(vec3( x.z + 74.2 , x.x - 124.5 , x.y + 99.4 ));
|
|
return vec3( s , s1 , s2 );
|
|
}
|
|
|
|
fn snoise34(x: vec4f) -> vec3f {
|
|
let s = snoise4(vec4( x ));
|
|
let s1 = snoise4(vec4( x.y - 19.1 , x.z + 33.4 , x.x + 47.2, x.w ));
|
|
let s2 = snoise4(vec4( x.z + 74.2 , x.x - 124.5 , x.y + 99.4, x.w ));
|
|
return vec3( s , s1 , s2 );
|
|
}
|