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316 lines
13 KiB
316 lines
13 KiB
// stb_perlin.h - v0.3 - perlin noise |
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// public domain single-file C implementation by Sean Barrett |
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// |
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// LICENSE |
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// |
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// See end of file. |
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// |
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// |
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// to create the implementation, |
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// #define STB_PERLIN_IMPLEMENTATION |
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// in *one* C/CPP file that includes this file. |
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// |
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// |
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// Documentation: |
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// |
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// float stb_perlin_noise3( float x, |
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// float y, |
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// float z, |
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// int x_wrap=0, |
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// int y_wrap=0, |
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// int z_wrap=0) |
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// |
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// This function computes a random value at the coordinate (x,y,z). |
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// Adjacent random values are continuous but the noise fluctuates |
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// its randomness with period 1, i.e. takes on wholly unrelated values |
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// at integer points. Specifically, this implements Ken Perlin's |
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// revised noise function from 2002. |
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// |
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// The "wrap" parameters can be used to create wraparound noise that |
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// wraps at powers of two. The numbers MUST be powers of two. Specify |
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// 0 to mean "don't care". (The noise always wraps every 256 due |
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// details of the implementation, even if you ask for larger or no |
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// wrapping.) |
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// |
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// Fractal Noise: |
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// |
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// Three common fractal noise functions are included, which produce |
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// a wide variety of nice effects depending on the parameters |
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// provided. Note that each function will call stb_perlin_noise3 |
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// 'octaves' times, so this parameter will affect runtime. |
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// |
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// float stb_perlin_ridge_noise3(float x, float y, float z, |
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// float lacunarity, float gain, float offset, int octaves, |
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// int x_wrap, int y_wrap, int z_wrap); |
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// |
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// float stb_perlin_fbm_noise3(float x, float y, float z, |
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// float lacunarity, float gain, int octaves, |
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// int x_wrap, int y_wrap, int z_wrap); |
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// |
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// float stb_perlin_turbulence_noise3(float x, float y, float z, |
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// float lacunarity, float gain,int octaves, |
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// int x_wrap, int y_wrap, int z_wrap); |
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// |
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// Typical values to start playing with: |
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// octaves = 6 -- number of "octaves" of noise3() to sum |
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// lacunarity = ~ 2.0 -- spacing between successive octaves (use exactly 2.0 for wrapping output) |
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// gain = 0.5 -- relative weighting applied to each successive octave |
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// offset = 1.0? -- used to invert the ridges, may need to be larger, not sure |
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// |
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// |
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// Contributors: |
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// Jack Mott - additional noise functions |
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// |
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#ifdef __cplusplus |
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extern "C" { |
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#endif |
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extern float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z_wrap); |
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extern float stb_perlin_ridge_noise3(float x, float y, float z,float lacunarity, float gain, float offset, int octaves,int x_wrap, int y_wrap, int z_wrap); |
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extern float stb_perlin_fbm_noise3(float x, float y, float z,float lacunarity, float gain, int octaves,int x_wrap, int y_wrap, int z_wrap); |
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extern float stb_perlin_turbulence_noise3(float x, float y, float z, float lacunarity, float gain, int octaves,int x_wrap, int y_wrap, int z_wrap); |
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#ifdef __cplusplus |
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} |
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#endif |
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#ifdef STB_PERLIN_IMPLEMENTATION |
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// not same permutation table as Perlin's reference to avoid copyright issues; |
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// Perlin's table can be found at http://mrl.nyu.edu/~perlin/noise/ |
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// @OPTIMIZE: should this be unsigned char instead of int for cache? |
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static unsigned char stb__perlin_randtab[512] = |
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{ |
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23, 125, 161, 52, 103, 117, 70, 37, 247, 101, 203, 169, 124, 126, 44, 123, |
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152, 238, 145, 45, 171, 114, 253, 10, 192, 136, 4, 157, 249, 30, 35, 72, |
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175, 63, 77, 90, 181, 16, 96, 111, 133, 104, 75, 162, 93, 56, 66, 240, |
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8, 50, 84, 229, 49, 210, 173, 239, 141, 1, 87, 18, 2, 198, 143, 57, |
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225, 160, 58, 217, 168, 206, 245, 204, 199, 6, 73, 60, 20, 230, 211, 233, |
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94, 200, 88, 9, 74, 155, 33, 15, 219, 130, 226, 202, 83, 236, 42, 172, |
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165, 218, 55, 222, 46, 107, 98, 154, 109, 67, 196, 178, 127, 158, 13, 243, |
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65, 79, 166, 248, 25, 224, 115, 80, 68, 51, 184, 128, 232, 208, 151, 122, |
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26, 212, 105, 43, 179, 213, 235, 148, 146, 89, 14, 195, 28, 78, 112, 76, |
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250, 47, 24, 251, 140, 108, 186, 190, 228, 170, 183, 139, 39, 188, 244, 246, |
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132, 48, 119, 144, 180, 138, 134, 193, 82, 182, 120, 121, 86, 220, 209, 3, |
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91, 241, 149, 85, 205, 150, 113, 216, 31, 100, 41, 164, 177, 214, 153, 231, |
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38, 71, 185, 174, 97, 201, 29, 95, 7, 92, 54, 254, 191, 118, 34, 221, |
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131, 11, 163, 99, 234, 81, 227, 147, 156, 176, 17, 142, 69, 12, 110, 62, |
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27, 255, 0, 194, 59, 116, 242, 252, 19, 21, 187, 53, 207, 129, 64, 135, |
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61, 40, 167, 237, 102, 223, 106, 159, 197, 189, 215, 137, 36, 32, 22, 5, |
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// and a second copy so we don't need an extra mask or static initializer |
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23, 125, 161, 52, 103, 117, 70, 37, 247, 101, 203, 169, 124, 126, 44, 123, |
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152, 238, 145, 45, 171, 114, 253, 10, 192, 136, 4, 157, 249, 30, 35, 72, |
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175, 63, 77, 90, 181, 16, 96, 111, 133, 104, 75, 162, 93, 56, 66, 240, |
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8, 50, 84, 229, 49, 210, 173, 239, 141, 1, 87, 18, 2, 198, 143, 57, |
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225, 160, 58, 217, 168, 206, 245, 204, 199, 6, 73, 60, 20, 230, 211, 233, |
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94, 200, 88, 9, 74, 155, 33, 15, 219, 130, 226, 202, 83, 236, 42, 172, |
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165, 218, 55, 222, 46, 107, 98, 154, 109, 67, 196, 178, 127, 158, 13, 243, |
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65, 79, 166, 248, 25, 224, 115, 80, 68, 51, 184, 128, 232, 208, 151, 122, |
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26, 212, 105, 43, 179, 213, 235, 148, 146, 89, 14, 195, 28, 78, 112, 76, |
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250, 47, 24, 251, 140, 108, 186, 190, 228, 170, 183, 139, 39, 188, 244, 246, |
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132, 48, 119, 144, 180, 138, 134, 193, 82, 182, 120, 121, 86, 220, 209, 3, |
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91, 241, 149, 85, 205, 150, 113, 216, 31, 100, 41, 164, 177, 214, 153, 231, |
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38, 71, 185, 174, 97, 201, 29, 95, 7, 92, 54, 254, 191, 118, 34, 221, |
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131, 11, 163, 99, 234, 81, 227, 147, 156, 176, 17, 142, 69, 12, 110, 62, |
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27, 255, 0, 194, 59, 116, 242, 252, 19, 21, 187, 53, 207, 129, 64, 135, |
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61, 40, 167, 237, 102, 223, 106, 159, 197, 189, 215, 137, 36, 32, 22, 5, |
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}; |
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static float stb__perlin_lerp(float a, float b, float t) |
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{ |
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return a + (b-a) * t; |
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} |
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static int stb__perlin_fastfloor(float a) |
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{ |
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int ai = (int) a; |
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return (a < ai) ? ai-1 : ai; |
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} |
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// different grad function from Perlin's, but easy to modify to match reference |
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static float stb__perlin_grad(int hash, float x, float y, float z) |
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{ |
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static float basis[12][4] = |
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{ |
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{ 1, 1, 0 }, |
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{ -1, 1, 0 }, |
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{ 1,-1, 0 }, |
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{ -1,-1, 0 }, |
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{ 1, 0, 1 }, |
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{ -1, 0, 1 }, |
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{ 1, 0,-1 }, |
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{ -1, 0,-1 }, |
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{ 0, 1, 1 }, |
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{ 0,-1, 1 }, |
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{ 0, 1,-1 }, |
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{ 0,-1,-1 }, |
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}; |
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// perlin's gradient has 12 cases so some get used 1/16th of the time |
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// and some 2/16ths. We reduce bias by changing those fractions |
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// to 5/64ths and 6/64ths, and the same 4 cases get the extra weight. |
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static unsigned char indices[64] = |
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{ |
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0,1,2,3,4,5,6,7,8,9,10,11, |
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0,9,1,11, |
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0,1,2,3,4,5,6,7,8,9,10,11, |
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0,1,2,3,4,5,6,7,8,9,10,11, |
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0,1,2,3,4,5,6,7,8,9,10,11, |
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0,1,2,3,4,5,6,7,8,9,10,11, |
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}; |
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// if you use reference permutation table, change 63 below to 15 to match reference |
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// (this is why the ordering of the table above is funky) |
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float *grad = basis[indices[hash & 63]]; |
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return grad[0]*x + grad[1]*y + grad[2]*z; |
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} |
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float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z_wrap) |
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{ |
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float u,v,w; |
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float n000,n001,n010,n011,n100,n101,n110,n111; |
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float n00,n01,n10,n11; |
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float n0,n1; |
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unsigned int x_mask = (x_wrap-1) & 255; |
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unsigned int y_mask = (y_wrap-1) & 255; |
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unsigned int z_mask = (z_wrap-1) & 255; |
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int px = stb__perlin_fastfloor(x); |
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int py = stb__perlin_fastfloor(y); |
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int pz = stb__perlin_fastfloor(z); |
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int x0 = px & x_mask, x1 = (px+1) & x_mask; |
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int y0 = py & y_mask, y1 = (py+1) & y_mask; |
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int z0 = pz & z_mask, z1 = (pz+1) & z_mask; |
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int r0,r1, r00,r01,r10,r11; |
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#define stb__perlin_ease(a) (((a*6-15)*a + 10) * a * a * a) |
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x -= px; u = stb__perlin_ease(x); |
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y -= py; v = stb__perlin_ease(y); |
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z -= pz; w = stb__perlin_ease(z); |
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r0 = stb__perlin_randtab[x0]; |
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r1 = stb__perlin_randtab[x1]; |
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r00 = stb__perlin_randtab[r0+y0]; |
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r01 = stb__perlin_randtab[r0+y1]; |
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r10 = stb__perlin_randtab[r1+y0]; |
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r11 = stb__perlin_randtab[r1+y1]; |
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n000 = stb__perlin_grad(stb__perlin_randtab[r00+z0], x , y , z ); |
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n001 = stb__perlin_grad(stb__perlin_randtab[r00+z1], x , y , z-1 ); |
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n010 = stb__perlin_grad(stb__perlin_randtab[r01+z0], x , y-1, z ); |
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n011 = stb__perlin_grad(stb__perlin_randtab[r01+z1], x , y-1, z-1 ); |
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n100 = stb__perlin_grad(stb__perlin_randtab[r10+z0], x-1, y , z ); |
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n101 = stb__perlin_grad(stb__perlin_randtab[r10+z1], x-1, y , z-1 ); |
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n110 = stb__perlin_grad(stb__perlin_randtab[r11+z0], x-1, y-1, z ); |
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n111 = stb__perlin_grad(stb__perlin_randtab[r11+z1], x-1, y-1, z-1 ); |
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n00 = stb__perlin_lerp(n000,n001,w); |
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n01 = stb__perlin_lerp(n010,n011,w); |
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n10 = stb__perlin_lerp(n100,n101,w); |
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n11 = stb__perlin_lerp(n110,n111,w); |
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n0 = stb__perlin_lerp(n00,n01,v); |
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n1 = stb__perlin_lerp(n10,n11,v); |
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return stb__perlin_lerp(n0,n1,u); |
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} |
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float stb_perlin_ridge_noise3(float x, float y, float z,float lacunarity, float gain, float offset, int octaves,int x_wrap, int y_wrap, int z_wrap) |
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{ |
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int i; |
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float frequency = 1.0f; |
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float prev = 1.0f; |
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float amplitude = 0.5f; |
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float sum = 0.0f; |
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for (i = 0; i < octaves; i++) { |
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float r = (float)(stb_perlin_noise3(x*frequency,y*frequency,z*frequency,x_wrap,y_wrap,z_wrap)); |
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r = r<0 ? -r : r; // fabs() |
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r = offset - r; |
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r = r*r; |
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sum += r*amplitude*prev; |
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prev = r; |
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frequency *= lacunarity; |
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amplitude *= gain; |
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} |
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return sum; |
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} |
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float stb_perlin_fbm_noise3(float x, float y, float z,float lacunarity, float gain, int octaves,int x_wrap, int y_wrap, int z_wrap) |
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{ |
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int i; |
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float frequency = 1.0f; |
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float amplitude = 1.0f; |
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float sum = 0.0f; |
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for (i = 0; i < octaves; i++) { |
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sum += stb_perlin_noise3(x*frequency,y*frequency,z*frequency,x_wrap,y_wrap,z_wrap)*amplitude; |
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frequency *= lacunarity; |
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amplitude *= gain; |
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} |
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return sum; |
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} |
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float stb_perlin_turbulence_noise3(float x, float y, float z, float lacunarity, float gain, int octaves,int x_wrap, int y_wrap, int z_wrap) |
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{ |
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int i; |
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float frequency = 1.0f; |
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float amplitude = 1.0f; |
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float sum = 0.0f; |
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for (i = 0; i < octaves; i++) { |
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float r = stb_perlin_noise3(x*frequency,y*frequency,z*frequency,x_wrap,y_wrap,z_wrap)*amplitude; |
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r = r<0 ? -r : r; // fabs() |
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sum += r; |
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frequency *= lacunarity; |
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amplitude *= gain; |
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} |
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return sum; |
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} |
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#endif // STB_PERLIN_IMPLEMENTATION |
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/* |
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------------------------------------------------------------------------------ |
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This software is available under 2 licenses -- choose whichever you prefer. |
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------------------------------------------------------------------------------ |
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ALTERNATIVE A - MIT License |
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Copyright (c) 2017 Sean Barrett |
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Permission is hereby granted, free of charge, to any person obtaining a copy of |
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this software and associated documentation files (the "Software"), to deal in |
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the Software without restriction, including without limitation the rights to |
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use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies |
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of the Software, and to permit persons to whom the Software is furnished to do |
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so, subject to the following conditions: |
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The above copyright notice and this permission notice shall be included in all |
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copies or substantial portions of the Software. |
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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 THE |
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SOFTWARE. |
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------------------------------------------------------------------------------ |
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ALTERNATIVE B - Public Domain (www.unlicense.org) |
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This is free and unencumbered software released into the public domain. |
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Anyone is free to copy, modify, publish, use, compile, sell, or distribute this |
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software, either in source code form or as a compiled binary, for any purpose, |
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commercial or non-commercial, and by any means. |
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In jurisdictions that recognize copyright laws, the author or authors of this |
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software dedicate any and all copyright interest in the software to the public |
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domain. We make this dedication for the benefit of the public at large and to |
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the detriment of our heirs and successors. We intend this dedication to be an |
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overt act of relinquishment in perpetuity of all present and future rights to |
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this software under copyright law. |
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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 BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
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ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION |
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WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
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------------------------------------------------------------------------------ |
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*/
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