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115 lines
3.4 KiB
Plaintext
115 lines
3.4 KiB
Plaintext
2 weeks ago
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/******************************************************************************/
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/*
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Project - MudBun
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Publisher - Long Bunny Labs
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http://LongBunnyLabs.com
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Author - Ming-Lun "Allen" Chou
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http://AllenChou.net
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Based on project "webgl-noise" by Ashima Arts.
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Description : Array and textureless GLSL 2D simplex noise function.
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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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#ifndef MUDBUN_CLASSIC_NOISE_2D
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#define MUDBUN_CLASSIC_NOISE_2D
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#include "NoiseCommon.cginc"
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// classic Perlin noise
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// single octave
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float mbn_cnoise(float2 P)
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{
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float4 Pi = floor(P.xyxy) + float4(0.0, 0.0, 1.0, 1.0);
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float4 Pf = frac (P.xyxy) - float4(0.0, 0.0, 1.0, 1.0);
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Pi = mbn_mod289(Pi); // To avoid truncation effects in permutation
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float4 ix = Pi.xzxz;
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float4 iy = Pi.yyww;
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float4 fx = Pf.xzxz;
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float4 fy = Pf.yyww;
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float4 i = mbn_permute(mbn_permute(ix) + iy);
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float4 gx = frac(i / 41.0) * 2.0 - 1.0 ;
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float4 gy = abs(gx) - 0.5 ;
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float4 tx = floor(gx + 0.5);
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gx = gx - tx;
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float2 g00 = float2(gx.x,gy.x);
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float2 g10 = float2(gx.y,gy.y);
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float2 g01 = float2(gx.z,gy.z);
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float2 g11 = float2(gx.w,gy.w);
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float4 norm = mbn_taylorInvSqrt(float4(dot(g00, g00), dot(g01, g01), dot(g10, g10), dot(g11, g11)));
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g00 *= norm.x;
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g01 *= norm.y;
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g10 *= norm.z;
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g11 *= norm.w;
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float n00 = dot(g00, float2(fx.x, fy.x));
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float n10 = dot(g10, float2(fx.y, fy.y));
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float n01 = dot(g01, float2(fx.z, fy.z));
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float n11 = dot(g11, float2(fx.w, fy.w));
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float2 fade_xy = mbn_fade(Pf.xy);
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float2 n_x = lerp(float2(n00, n01), float2(n10, n11), fade_xy.x);
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float n_xy = lerp(n_x.x, n_x.y, fade_xy.y);
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return 2.3 * n_xy;
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}
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// multiple octaves
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DEFINE_NOISE_FUNC_MULTIPLE_OCTAVES(mbn_cnoise, float, float2, 0.5)
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// classic Perlin noise, periodic variant
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// single octave
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float mbn_noise(float2 P, float2 rep)
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{
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float4 Pi = floor(P.xyxy) + float4(0.0, 0.0, 1.0, 1.0);
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float4 Pf = frac (P.xyxy) - float4(0.0, 0.0, 1.0, 1.0);
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Pi = mbn_mod(Pi, rep.xyxy); // To create noise with explicit period
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Pi = mbn_mod289(Pi); // To avoid truncation effects in permutation
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float4 ix = Pi.xzxz;
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float4 iy = Pi.yyww;
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float4 fx = Pf.xzxz;
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float4 fy = Pf.yyww;
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float4 i = mbn_permute(mbn_permute(ix) + iy);
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float4 gx = frac(i / 41.0) * 2.0 - 1.0 ;
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float4 gy = abs(gx) - 0.5 ;
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float4 tx = floor(gx + 0.5);
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gx = gx - tx;
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float2 g00 = float2(gx.x,gy.x);
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float2 g10 = float2(gx.y,gy.y);
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float2 g01 = float2(gx.z,gy.z);
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float2 g11 = float2(gx.w,gy.w);
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float4 norm = mbn_taylorInvSqrt(float4(dot(g00, g00), dot(g01, g01), dot(g10, g10), dot(g11, g11)));
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g00 *= norm.x;
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g01 *= norm.y;
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g10 *= norm.z;
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g11 *= norm.w;
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float n00 = dot(g00, float2(fx.x, fy.x));
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float n10 = dot(g10, float2(fx.y, fy.y));
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float n01 = dot(g01, float2(fx.z, fy.z));
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float n11 = dot(g11, float2(fx.w, fy.w));
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float2 fade_xy = mbn_fade(Pf.xy);
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float2 n_x = lerp(float2(n00, n01), float2(n10, n11), fade_xy.x);
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float n_xy = lerp(n_x.x, n_x.y, fade_xy.y);
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return 2.3 * n_xy;
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}
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// multiple octave
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DEFINE_PERIODIC_NOISE_FUNC_MULTIPLE_OCTAVES(mbn_pnoise, float, float2)
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#endif
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