diff --git a/stb_perlin.h b/stb_perlin.h index 5d76222..2d95dd6 100644 --- a/stb_perlin.h +++ b/stb_perlin.h @@ -1,4 +1,4 @@ -// stb_perlin.h - v0.3 - perlin noise +// stb_perlin.h - v0.4 - perlin noise // public domain single-file C implementation by Sean Barrett // // LICENSE @@ -18,7 +18,8 @@ // float z, // int x_wrap=0, // int y_wrap=0, -// int z_wrap=0) +// int z_wrap=0, +// unsigned char seed=0) // // This function computes a random value at the coordinate (x,y,z). // Adjacent random values are continuous but the noise fluctuates @@ -32,6 +33,9 @@ // details of the implementation, even if you ask for larger or no // wrapping.) // +// Using a different "seed" will provide a unique variation +// of the noise output. +// // Fractal Noise: // // Three common fractal noise functions are included, which produce @@ -41,15 +45,15 @@ // // 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); +// unsigned char seed=0) // // 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); +// unsigned char seed=0); // // 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); +// unsigned char seed=0) // // Typical values to start playing with: // octaves = 6 -- number of "octaves" of noise3() to sum @@ -60,25 +64,27 @@ // // Contributors: // Jack Mott - additional noise functions +// Jordan Peck - seeded noise // #ifdef __cplusplus extern "C" { #endif -extern float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z_wrap); -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); -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); -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); +extern float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z_wrap, unsigned char seed); +extern float stb_perlin_ridge_noise3(float x, float y, float z, float lacunarity, float gain, float offset, int octaves, unsigned char seed); +extern float stb_perlin_fbm_noise3(float x, float y, float z, float lacunarity, float gain, int octaves, unsigned char seed); +extern float stb_perlin_turbulence_noise3(float x, float y, float z, float lacunarity, float gain, int octaves, unsigned char seed); #ifdef __cplusplus } #endif #ifdef STB_PERLIN_IMPLEMENTATION +#include // fabs() + // not same permutation table as Perlin's reference to avoid copyright issues; // Perlin's table can be found at http://mrl.nyu.edu/~perlin/noise/ -// @OPTIMIZE: should this be unsigned char instead of int for cache? static unsigned char stb__perlin_randtab[512] = { 23, 125, 161, 52, 103, 117, 70, 37, 247, 101, 203, 169, 124, 126, 44, 123, @@ -115,6 +121,50 @@ static unsigned char stb__perlin_randtab[512] = 131, 11, 163, 99, 234, 81, 227, 147, 156, 176, 17, 142, 69, 12, 110, 62, 27, 255, 0, 194, 59, 116, 242, 252, 19, 21, 187, 53, 207, 129, 64, 135, 61, 40, 167, 237, 102, 223, 106, 159, 197, 189, 215, 137, 36, 32, 22, 5, +}; + + +// perlin's gradient has 12 cases so some get used 1/16th of the time +// and some 2/16ths. We reduce bias by changing those fractions +// to 21/256ths and 22/256ths + +// same as array above but with value % 12 +static unsigned char stb__perlin_randtab_mod12[512] = +{ + 11, 5, 5, 4, 7, 9, 10, 1, 7, 5, 11, 1, 4, 6, 8, 3, + 8, 10, 1, 9, 3, 6, 1, 10, 0, 4, 4, 1, 9, 6, 11, 0, + 7, 3, 5, 6, 1, 4, 0, 3, 1, 8, 3, 6, 9, 8, 6, 0, + 8, 2, 0, 1, 1, 6, 5, 11, 9, 1, 3, 6, 2, 6, 11, 9, + 9, 4, 10, 1, 0, 2, 5, 0, 7, 6, 1, 0, 8, 2, 7, 5, + 10, 8, 4, 9, 2, 11, 9, 3, 3, 10, 10, 10, 11, 8, 6, 4, + 9, 2, 7, 6, 10, 11, 2, 10, 1, 7, 4, 10, 7, 2, 1, 3, + 5, 7, 10, 8, 1, 8, 7, 8, 8, 3, 4, 8, 4, 4, 7, 2, + 2, 8, 9, 7, 11, 9, 7, 4, 2, 5, 2, 3, 4, 6, 4, 4, + 10, 11, 0, 11, 8, 0, 6, 10, 0, 2, 3, 7, 3, 8, 4, 6, + 0, 0, 11, 0, 0, 6, 2, 1, 10, 2, 0, 1, 2, 4, 5, 3, + 7, 1, 5, 1, 1, 6, 5, 0, 7, 4, 5, 8, 9, 10, 9, 3, + 2, 11, 5, 6, 1, 9, 5, 11, 7, 8, 6, 2, 11, 10, 10, 5, + 11, 11, 7, 3, 6, 9, 11, 3, 0, 8, 5, 10, 9, 0, 2, 2, + 3, 3, 0, 2, 11, 8, 2, 0, 7, 9, 7, 5, 3, 9, 4, 3, + 1, 4, 11, 9, 6, 7, 10, 3, 5, 9, 11, 5, 0, 8, 10, 5, + + // and a second copy so we don't need an extra mask or static initializer + 11, 5, 5, 4, 7, 9, 10, 1, 7, 5, 11, 1, 4, 6, 8, 3, + 8, 10, 1, 9, 3, 6, 1, 10, 0, 4, 4, 1, 9, 6, 11, 0, + 7, 3, 5, 6, 1, 4, 0, 3, 1, 8, 3, 6, 9, 8, 6, 0, + 8, 2, 0, 1, 1, 6, 5, 11, 9, 1, 3, 6, 2, 6, 11, 9, + 9, 4, 10, 1, 0, 2, 5, 0, 7, 6, 1, 0, 8, 2, 7, 5, + 10, 8, 4, 9, 2, 11, 9, 3, 3, 10, 10, 10, 11, 8, 6, 4, + 9, 2, 7, 6, 10, 11, 2, 10, 1, 7, 4, 10, 7, 2, 1, 3, + 5, 7, 10, 8, 1, 8, 7, 8, 8, 3, 4, 8, 4, 4, 7, 2, + 2, 8, 9, 7, 11, 9, 7, 4, 2, 5, 2, 3, 4, 6, 4, 4, + 10, 11, 0, 11, 8, 0, 6, 10, 0, 2, 3, 7, 3, 8, 4, 6, + 0, 0, 11, 0, 0, 6, 2, 1, 10, 2, 0, 1, 2, 4, 5, 3, + 7, 1, 5, 1, 1, 6, 5, 0, 7, 4, 5, 8, 9, 10, 9, 3, + 2, 11, 5, 6, 1, 9, 5, 11, 7, 8, 6, 2, 11, 10, 10, 5, + 11, 11, 7, 3, 6, 9, 11, 3, 0, 8, 5, 10, 9, 0, 2, 2, + 3, 3, 0, 2, 11, 8, 2, 0, 7, 9, 7, 5, 3, 9, 4, 3, + 1, 4, 11, 9, 6, 7, 10, 3, 5, 9, 11, 5, 0, 8, 10, 5, }; static float stb__perlin_lerp(float a, float b, float t) @@ -124,12 +174,12 @@ static float stb__perlin_lerp(float a, float b, float t) static int stb__perlin_fastfloor(float a) { - int ai = (int) a; - return (a < ai) ? ai-1 : ai; + int ai = (int) a; + return (a < ai) ? ai-1 : ai; } // different grad function from Perlin's, but easy to modify to match reference -static float stb__perlin_grad(int hash, float x, float y, float z) +static float stb__perlin_grad(int grad_idx, float x, float y, float z) { static float basis[12][4] = { @@ -147,26 +197,11 @@ static float stb__perlin_grad(int hash, float x, float y, float z) { 0,-1,-1 }, }; - // perlin's gradient has 12 cases so some get used 1/16th of the time - // and some 2/16ths. We reduce bias by changing those fractions - // to 5/64ths and 6/64ths, and the same 4 cases get the extra weight. - static unsigned char indices[64] = - { - 0,1,2,3,4,5,6,7,8,9,10,11, - 0,9,1,11, - 0,1,2,3,4,5,6,7,8,9,10,11, - 0,1,2,3,4,5,6,7,8,9,10,11, - 0,1,2,3,4,5,6,7,8,9,10,11, - 0,1,2,3,4,5,6,7,8,9,10,11, - }; - - // if you use reference permutation table, change 63 below to 15 to match reference - // (this is why the ordering of the table above is funky) - float *grad = basis[indices[hash & 63]]; + float *grad = basis[grad_idx]; return grad[0]*x + grad[1]*y + grad[2]*z; } -float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z_wrap) +float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z_wrap, unsigned char seed) { float u,v,w; float n000,n001,n010,n011,n100,n101,n110,n111; @@ -190,22 +225,22 @@ float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z y -= py; v = stb__perlin_ease(y); z -= pz; w = stb__perlin_ease(z); - r0 = stb__perlin_randtab[x0]; - r1 = stb__perlin_randtab[x1]; + r0 = stb__perlin_randtab[x0+seed]; + r1 = stb__perlin_randtab[x1+seed]; r00 = stb__perlin_randtab[r0+y0]; r01 = stb__perlin_randtab[r0+y1]; r10 = stb__perlin_randtab[r1+y0]; r11 = stb__perlin_randtab[r1+y1]; - n000 = stb__perlin_grad(stb__perlin_randtab[r00+z0], x , y , z ); - n001 = stb__perlin_grad(stb__perlin_randtab[r00+z1], x , y , z-1 ); - n010 = stb__perlin_grad(stb__perlin_randtab[r01+z0], x , y-1, z ); - n011 = stb__perlin_grad(stb__perlin_randtab[r01+z1], x , y-1, z-1 ); - n100 = stb__perlin_grad(stb__perlin_randtab[r10+z0], x-1, y , z ); - n101 = stb__perlin_grad(stb__perlin_randtab[r10+z1], x-1, y , z-1 ); - n110 = stb__perlin_grad(stb__perlin_randtab[r11+z0], x-1, y-1, z ); - n111 = stb__perlin_grad(stb__perlin_randtab[r11+z1], x-1, y-1, z-1 ); + n000 = stb__perlin_grad(stb__perlin_randtab_mod12[r00+z0], x , y , z ); + n001 = stb__perlin_grad(stb__perlin_randtab_mod12[r00+z1], x , y , z-1 ); + n010 = stb__perlin_grad(stb__perlin_randtab_mod12[r01+z0], x , y-1, z ); + n011 = stb__perlin_grad(stb__perlin_randtab_mod12[r01+z1], x , y-1, z-1 ); + n100 = stb__perlin_grad(stb__perlin_randtab_mod12[r10+z0], x-1, y , z ); + n101 = stb__perlin_grad(stb__perlin_randtab_mod12[r10+z1], x-1, y , z-1 ); + n110 = stb__perlin_grad(stb__perlin_randtab_mod12[r11+z0], x-1, y-1, z ); + n111 = stb__perlin_grad(stb__perlin_randtab_mod12[r11+z1], x-1, y-1, z-1 ); n00 = stb__perlin_lerp(n000,n001,w); n01 = stb__perlin_lerp(n010,n011,w); @@ -218,7 +253,7 @@ float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z return stb__perlin_lerp(n0,n1,u); } -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) +float stb_perlin_ridge_noise3(float x, float y, float z, float lacunarity, float gain, float offset, int octaves, unsigned char seed) { int i; float frequency = 1.0f; @@ -227,19 +262,19 @@ float stb_perlin_ridge_noise3(float x, float y, float z,float lacunarity, float float sum = 0.0f; for (i = 0; i < octaves; i++) { - float r = (float)(stb_perlin_noise3(x*frequency,y*frequency,z*frequency,x_wrap,y_wrap,z_wrap)); - r = r<0 ? -r : r; // fabs() - r = offset - r; + float r = stb_perlin_noise3(x*frequency,y*frequency,z*frequency,0,0,0,seed); + r = offset - fabs(r); r = r*r; sum += r*amplitude*prev; prev = r; frequency *= lacunarity; amplitude *= gain; + seed++; } return sum; } -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) +float stb_perlin_fbm_noise3(float x, float y, float z, float lacunarity, float gain, int octaves, unsigned char seed) { int i; float frequency = 1.0f; @@ -247,14 +282,15 @@ float stb_perlin_fbm_noise3(float x, float y, float z,float lacunarity, float ga float sum = 0.0f; for (i = 0; i < octaves; i++) { - sum += stb_perlin_noise3(x*frequency,y*frequency,z*frequency,x_wrap,y_wrap,z_wrap)*amplitude; + sum += stb_perlin_noise3(x*frequency,y*frequency,z*frequency,0,0,0,seed)*amplitude; frequency *= lacunarity; amplitude *= gain; + seed++; } return sum; } -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) +float stb_perlin_turbulence_noise3(float x, float y, float z, float lacunarity, float gain, int octaves, unsigned char seed) { int i; float frequency = 1.0f; @@ -262,11 +298,11 @@ float stb_perlin_turbulence_noise3(float x, float y, float z, float lacunarity, float sum = 0.0f; for (i = 0; i < octaves; i++) { - float r = stb_perlin_noise3(x*frequency,y*frequency,z*frequency,x_wrap,y_wrap,z_wrap)*amplitude; - r = r<0 ? -r : r; // fabs() - sum += r; + float r = stb_perlin_noise3(x*frequency,y*frequency,z*frequency,0,0,0,seed)*amplitude; + sum += fabs(r); frequency *= lacunarity; amplitude *= gain; + seed++; } return sum; }