464 lines
11 KiB
HLSL
464 lines
11 KiB
HLSL
#ifndef NOISE_SIMPLEX_FUNC
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#define NOISE_SIMPLEX_FUNC
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/*
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Description:
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Array- and textureless CgFx/HLSL 2D, 3D and 4D simplex noise functions.
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a.k.a. simplified and optimized Perlin noise.
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The functions have very good performance
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and no dependencies on external data.
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2D - Very fast, very compact code.
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3D - Fast, compact code.
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4D - Reasonably fast, reasonably compact code.
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------------------------------------------------------------------
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Ported by:
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Lex-DRL
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I've ported the code from GLSL to CgFx/HLSL for Unity,
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added a couple more optimisations (to speed it up even further)
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and slightly reformatted the code to make it more readable.
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Original GLSL functions:
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https://github.com/ashima/webgl-noise
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Credits from original glsl file are at the end of this cginc.
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------------------------------------------------------------------
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Usage:
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float ns = snoise(v);
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// v is any of: float2, float3, float4
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Return type is float.
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To generate 2 or more components of noise (colorful noise),
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call these functions several times with different
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constant offsets for the arguments.
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E.g.:
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float3 colorNs = float3(
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snoise(v),
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snoise(v + 17.0),
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snoise(v - 43.0),
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);
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Remark about those offsets from the original author:
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People have different opinions on whether these offsets should be integers
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for the classic noise functions to match the spacing of the zeroes,
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so we have left that for you to decide for yourself.
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For most applications, the exact offsets don't really matter as long
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as they are not too small or too close to the noise lattice period
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(289 in this implementation).
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*/
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// 1 / 289
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#define NOISE_SIMPLEX_1_DIV_289 0.00346020761245674740484429065744f
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float mod289(float x) {
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return x - floor(x * NOISE_SIMPLEX_1_DIV_289) * 289.0;
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}
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float2 mod289(float2 x) {
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return x - floor(x * NOISE_SIMPLEX_1_DIV_289) * 289.0;
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}
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float3 mod289(float3 x) {
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return x - floor(x * NOISE_SIMPLEX_1_DIV_289) * 289.0;
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}
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float4 mod289(float4 x) {
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return x - floor(x * NOISE_SIMPLEX_1_DIV_289) * 289.0;
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}
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// ( x*34.0 + 1.0 )*x =
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// x*x*34.0 + x
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float permute(float x) {
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return mod289(
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x*x*34.0 + x
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);
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}
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float3 permute(float3 x) {
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return mod289(
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x*x*34.0 + x
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);
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}
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float4 permute(float4 x) {
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return mod289(
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x*x*34.0 + x
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);
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}
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float taylorInvSqrt(float r) {
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return 1.79284291400159 - 0.85373472095314 * r;
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}
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float4 taylorInvSqrt(float4 r) {
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return 1.79284291400159 - 0.85373472095314 * r;
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}
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float4 grad4(float j, float4 ip)
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{
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const float4 ones = float4(1.0, 1.0, 1.0, -1.0);
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float4 p, s;
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p.xyz = floor( frac(j * ip.xyz) * 7.0) * ip.z - 1.0;
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p.w = 1.5 - dot( abs(p.xyz), ones.xyz );
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// GLSL: lessThan(x, y) = x < y
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// HLSL: 1 - step(y, x) = x < y
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s = float4(
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1 - step(0.0, p)
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);
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p.xyz = p.xyz + (s.xyz * 2 - 1) * s.www;
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return p;
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}
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// ----------------------------------- 2D -------------------------------------
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float snoise(float2 v)
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{
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const float4 C = float4(
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0.211324865405187, // (3.0-sqrt(3.0))/6.0
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0.366025403784439, // 0.5*(sqrt(3.0)-1.0)
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-0.577350269189626, // -1.0 + 2.0 * C.x
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0.024390243902439 // 1.0 / 41.0
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);
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// First corner
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float2 i = floor( v + dot(v, C.yy) );
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float2 x0 = v - i + dot(i, C.xx);
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// Other corners
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// float2 i1 = (x0.x > x0.y) ? float2(1.0, 0.0) : float2(0.0, 1.0);
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// Lex-DRL: afaik, step() in GPU is faster than if(), so:
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// step(x, y) = x <= y
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int xLessEqual = step(x0.x, x0.y); // x <= y ?
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int2 i1 =
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int2(1, 0) * (1 - xLessEqual) // x > y
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+ int2(0, 1) * xLessEqual // x <= y
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;
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float4 x12 = x0.xyxy + C.xxzz;
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x12.xy -= i1;
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// Permutations
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i = mod289(i); // Avoid truncation effects in permutation
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float3 p = permute(
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permute(
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i.y + float3(0.0, i1.y, 1.0 )
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) + i.x + float3(0.0, i1.x, 1.0 )
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);
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float3 m = max(
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0.5 - float3(
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dot(x0, x0),
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dot(x12.xy, x12.xy),
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dot(x12.zw, x12.zw)
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),
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0.0
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);
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m = m*m ;
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m = m*m ;
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// Gradients: 41 points uniformly over a line, mapped onto a diamond.
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// The ring size 17*17 = 289 is close to a multiple of 41 (41*7 = 287)
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float3 x = 2.0 * frac(p * C.www) - 1.0;
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float3 h = abs(x) - 0.5;
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float3 ox = floor(x + 0.5);
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float3 a0 = x - ox;
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// Normalise gradients implicitly by scaling m
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// Approximation of: m *= inversesqrt( a0*a0 + h*h );
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m *= 1.79284291400159 - 0.85373472095314 * ( a0*a0 + h*h );
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// Compute final noise value at P
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float3 g;
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g.x = a0.x * x0.x + h.x * x0.y;
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g.yz = a0.yz * x12.xz + h.yz * x12.yw;
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return 130.0 * dot(m, g);
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}
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// ----------------------------------- 3D -------------------------------------
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float snoise(float3 v)
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{
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const float2 C = float2(
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0.166666666666666667, // 1/6
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0.333333333333333333 // 1/3
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);
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const float4 D = float4(0.0, 0.5, 1.0, 2.0);
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// First corner
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float3 i = floor( v + dot(v, C.yyy) );
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float3 x0 = v - i + dot(i, C.xxx);
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// Other corners
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float3 g = step(x0.yzx, x0.xyz);
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float3 l = 1 - g;
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float3 i1 = min(g.xyz, l.zxy);
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float3 i2 = max(g.xyz, l.zxy);
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float3 x1 = x0 - i1 + C.xxx;
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float3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
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float3 x3 = x0 - D.yyy; // -1.0+3.0*C.x = -0.5 = -D.y
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// Permutations
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i = mod289(i);
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float4 p = permute(
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permute(
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permute(
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i.z + float4(0.0, i1.z, i2.z, 1.0 )
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) + i.y + float4(0.0, i1.y, i2.y, 1.0 )
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) + i.x + float4(0.0, i1.x, i2.x, 1.0 )
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);
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// Gradients: 7x7 points over a square, mapped onto an octahedron.
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// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
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float n_ = 0.142857142857; // 1/7
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float3 ns = n_ * D.wyz - D.xzx;
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float4 j = p - 49.0 * floor(p * ns.z * ns.z); // mod(p,7*7)
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float4 x_ = floor(j * ns.z);
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float4 y_ = floor(j - 7.0 * x_ ); // mod(j,N)
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float4 x = x_ *ns.x + ns.yyyy;
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float4 y = y_ *ns.x + ns.yyyy;
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float4 h = 1.0 - abs(x) - abs(y);
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float4 b0 = float4( x.xy, y.xy );
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float4 b1 = float4( x.zw, y.zw );
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//float4 s0 = float4(lessThan(b0,0.0))*2.0 - 1.0;
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//float4 s1 = float4(lessThan(b1,0.0))*2.0 - 1.0;
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float4 s0 = floor(b0)*2.0 + 1.0;
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float4 s1 = floor(b1)*2.0 + 1.0;
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float4 sh = -step(h, 0.0);
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float4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
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float4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;
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float3 p0 = float3(a0.xy,h.x);
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float3 p1 = float3(a0.zw,h.y);
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float3 p2 = float3(a1.xy,h.z);
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float3 p3 = float3(a1.zw,h.w);
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//Normalise gradients
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float4 norm = taylorInvSqrt(float4(
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dot(p0, p0),
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dot(p1, p1),
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dot(p2, p2),
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dot(p3, p3)
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));
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p0 *= norm.x;
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p1 *= norm.y;
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p2 *= norm.z;
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p3 *= norm.w;
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// Mix final noise value
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float4 m = max(
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0.6 - float4(
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dot(x0, x0),
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dot(x1, x1),
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dot(x2, x2),
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dot(x3, x3)
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),
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0.0
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);
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m = m * m;
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return 42.0 * dot(
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m*m,
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float4(
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dot(p0, x0),
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dot(p1, x1),
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dot(p2, x2),
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dot(p3, x3)
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)
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);
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}
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// ----------------------------------- 4D -------------------------------------
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float snoise(float4 v)
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{
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const float4 C = float4(
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0.138196601125011, // (5 - sqrt(5))/20 G4
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0.276393202250021, // 2 * G4
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0.414589803375032, // 3 * G4
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-0.447213595499958 // -1 + 4 * G4
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);
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// First corner
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float4 i = floor(
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v +
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dot(
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v,
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0.309016994374947451 // (sqrt(5) - 1) / 4
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)
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);
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float4 x0 = v - i + dot(i, C.xxxx);
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// Other corners
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// Rank sorting originally contributed by Bill Licea-Kane, AMD (formerly ATI)
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float4 i0;
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float3 isX = step( x0.yzw, x0.xxx );
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float3 isYZ = step( x0.zww, x0.yyz );
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i0.x = isX.x + isX.y + isX.z;
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i0.yzw = 1.0 - isX;
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i0.y += isYZ.x + isYZ.y;
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i0.zw += 1.0 - isYZ.xy;
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i0.z += isYZ.z;
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i0.w += 1.0 - isYZ.z;
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// i0 now contains the unique values 0,1,2,3 in each channel
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float4 i3 = saturate(i0);
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float4 i2 = saturate(i0-1.0);
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float4 i1 = saturate(i0-2.0);
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// x0 = x0 - 0.0 + 0.0 * C.xxxx
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// x1 = x0 - i1 + 1.0 * C.xxxx
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// x2 = x0 - i2 + 2.0 * C.xxxx
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// x3 = x0 - i3 + 3.0 * C.xxxx
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// x4 = x0 - 1.0 + 4.0 * C.xxxx
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float4 x1 = x0 - i1 + C.xxxx;
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float4 x2 = x0 - i2 + C.yyyy;
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float4 x3 = x0 - i3 + C.zzzz;
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float4 x4 = x0 + C.wwww;
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// Permutations
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i = mod289(i);
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float j0 = permute(
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permute(
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permute(
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permute(i.w) + i.z
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) + i.y
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) + i.x
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);
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float4 j1 = permute(
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permute(
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permute(
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permute (
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i.w + float4(i1.w, i2.w, i3.w, 1.0 )
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) + i.z + float4(i1.z, i2.z, i3.z, 1.0 )
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) + i.y + float4(i1.y, i2.y, i3.y, 1.0 )
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) + i.x + float4(i1.x, i2.x, i3.x, 1.0 )
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);
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// Gradients: 7x7x6 points over a cube, mapped onto a 4-cross polytope
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// 7*7*6 = 294, which is close to the ring size 17*17 = 289.
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const float4 ip = float4(
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0.003401360544217687075, // 1/294
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0.020408163265306122449, // 1/49
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0.142857142857142857143, // 1/7
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0.0
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);
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float4 p0 = grad4(j0, ip);
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float4 p1 = grad4(j1.x, ip);
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float4 p2 = grad4(j1.y, ip);
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float4 p3 = grad4(j1.z, ip);
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float4 p4 = grad4(j1.w, ip);
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// Normalise gradients
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float4 norm = taylorInvSqrt(float4(
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dot(p0, p0),
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dot(p1, p1),
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dot(p2, p2),
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dot(p3, p3)
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));
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p0 *= norm.x;
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p1 *= norm.y;
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p2 *= norm.z;
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p3 *= norm.w;
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p4 *= taylorInvSqrt( dot(p4, p4) );
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// Mix contributions from the five corners
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float3 m0 = max(
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0.6 - float3(
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dot(x0, x0),
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dot(x1, x1),
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dot(x2, x2)
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),
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0.0
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);
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float2 m1 = max(
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0.6 - float2(
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dot(x3, x3),
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dot(x4, x4)
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),
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0.0
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);
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m0 = m0 * m0;
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m1 = m1 * m1;
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return 49.0 * (
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dot(
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m0*m0,
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float3(
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dot(p0, x0),
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dot(p1, x1),
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dot(p2, x2)
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)
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) + dot(
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m1*m1,
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float2(
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dot(p3, x3),
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dot(p4, x4)
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)
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)
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);
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}
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// Credits from source glsl file:
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//
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// Description : Array and textureless GLSL 2D/3D/4D simplex
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// noise functions.
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// Author : Ian McEwan, Ashima Arts.
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// Maintainer : ijm
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// Lastmod : 20110822 (ijm)
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// License : Copyright (C) 2011 Ashima Arts. All rights reserved.
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// Distributed under the MIT License. See LICENSE file.
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// https://github.com/ashima/webgl-noise
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//
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//
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// The text from LICENSE file:
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//
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//
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// Copyright (C) 2011 by Ashima Arts (Simplex noise)
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// Copyright (C) 2011 by Stefan Gustavson (Classic noise)
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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#endif |