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Changed gradient idx table to match previous implementation, removed seeds from public API

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Jordan ago%!(EXTRA string=7 years)
parent 67f588cbb5
commit ca6548c30a
1 changed files with 61 additions and 58 deletions
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  1. 119
      stb_perlin.h

119
stb_perlin.h
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@ -1,4 +1,4 @@
// stb_perlin.h - v0.4 - perlin noise
// stb_perlin.h - v0.3 - perlin noise
// public domain single-file C implementation by Sean Barrett
//
// LICENSE
@ -71,10 +71,10 @@
#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, 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);
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);
extern float stb_perlin_fbm_noise3(float x, float y, float z, float lacunarity, float gain, int octaves);
extern float stb_perlin_turbulence_noise3(float x, float y, float z, float lacunarity, float gain, int octaves);
#ifdef __cplusplus
}
#endif
@ -126,45 +126,46 @@ static unsigned char stb__perlin_randtab[512] =
// 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
// to 5/64ths and 6/64ths
// same as array above but with value % 12
static unsigned char stb__perlin_randtab_mod12[512] =
// this array is designed to match the previous implementation
// of gradient hash: indices[stb__perlin_randtab[i]&63]
static unsigned char stb__perlin_randtab_grad_idx[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,
7, 9, 5, 0, 11, 1, 6, 9, 3, 9, 11, 1, 8, 10, 4, 7,
8, 6, 1, 5, 3, 10, 9, 10, 0, 8, 4, 1, 5, 2, 7, 8,
7, 11, 9, 10, 1, 0, 4, 7, 5, 0, 11, 6, 1, 4, 2, 8,
8, 10, 4, 9, 9, 2, 5, 7, 9, 1, 7, 2, 2, 6, 11, 5,
5, 4, 6, 9, 0, 1, 1, 0, 7, 6, 9, 8, 4, 10, 3, 1,
2, 8, 8, 9, 10, 11, 5, 11, 11, 2, 6, 10, 3, 4, 2, 4,
9, 10, 3, 2, 6, 3, 6, 10, 5, 3, 4, 10, 11, 2, 9, 11,
1, 11, 10, 4, 9, 4, 11, 0, 4, 11, 4, 0, 0, 0, 7, 6,
10, 4, 1, 3, 11, 5, 3, 4, 2, 9, 1, 3, 0, 1, 8, 0,
6, 7, 8, 7, 0, 4, 6, 10, 8, 2, 3, 11, 11, 8, 0, 2,
4, 8, 3, 0, 0, 10, 6, 1, 2, 2, 4, 5, 6, 0, 1, 3,
11, 9, 5, 5, 9, 6, 9, 8, 3, 8, 1, 8, 9, 6, 9, 11,
10, 7, 5, 6, 5, 9, 1, 3, 7, 0, 2, 10, 11, 2, 6, 1,
3, 11, 7, 7, 2, 1, 7, 3, 0, 8, 1, 1, 5, 0, 6, 10,
11, 11, 0, 2, 7, 0, 10, 8, 3, 5, 7, 1, 11, 1, 0, 7,
9, 0, 11, 5, 10, 3, 2, 3, 5, 9, 7, 9, 8, 4, 6, 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,
7, 9, 5, 0, 11, 1, 6, 9, 3, 9, 11, 1, 8, 10, 4, 7,
8, 6, 1, 5, 3, 10, 9, 10, 0, 8, 4, 1, 5, 2, 7, 8,
7, 11, 9, 10, 1, 0, 4, 7, 5, 0, 11, 6, 1, 4, 2, 8,
8, 10, 4, 9, 9, 2, 5, 7, 9, 1, 7, 2, 2, 6, 11, 5,
5, 4, 6, 9, 0, 1, 1, 0, 7, 6, 9, 8, 4, 10, 3, 1,
2, 8, 8, 9, 10, 11, 5, 11, 11, 2, 6, 10, 3, 4, 2, 4,
9, 10, 3, 2, 6, 3, 6, 10, 5, 3, 4, 10, 11, 2, 9, 11,
1, 11, 10, 4, 9, 4, 11, 0, 4, 11, 4, 0, 0, 0, 7, 6,
10, 4, 1, 3, 11, 5, 3, 4, 2, 9, 1, 3, 0, 1, 8, 0,
6, 7, 8, 7, 0, 4, 6, 10, 8, 2, 3, 11, 11, 8, 0, 2,
4, 8, 3, 0, 0, 10, 6, 1, 2, 2, 4, 5, 6, 0, 1, 3,
11, 9, 5, 5, 9, 6, 9, 8, 3, 8, 1, 8, 9, 6, 9, 11,
10, 7, 5, 6, 5, 9, 1, 3, 7, 0, 2, 10, 11, 2, 6, 1,
3, 11, 7, 7, 2, 1, 7, 3, 0, 8, 1, 1, 5, 0, 6, 10,
11, 11, 0, 2, 7, 0, 10, 8, 3, 5, 7, 1, 11, 1, 0, 7,
9, 0, 11, 5, 10, 3, 2, 3, 5, 9, 7, 9, 8, 4, 6, 5,
};
static float stb__perlin_lerp(float a, float b, float t)
@ -201,7 +202,7 @@ static float stb__perlin_grad(int grad_idx, float x, float y, float z)
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, unsigned char seed)
float stb_perlin_noise3_internal(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;
@ -233,14 +234,14 @@ float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z
r10 = stb__perlin_randtab[r1+y0];
r11 = stb__perlin_randtab[r1+y1];
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 );
n000 = stb__perlin_grad(stb__perlin_randtab_grad_idx[r00+z0], x , y , z );
n001 = stb__perlin_grad(stb__perlin_randtab_grad_idx[r00+z1], x , y , z-1 );
n010 = stb__perlin_grad(stb__perlin_randtab_grad_idx[r01+z0], x , y-1, z );
n011 = stb__perlin_grad(stb__perlin_randtab_grad_idx[r01+z1], x , y-1, z-1 );
n100 = stb__perlin_grad(stb__perlin_randtab_grad_idx[r10+z0], x-1, y , z );
n101 = stb__perlin_grad(stb__perlin_randtab_grad_idx[r10+z1], x-1, y , z-1 );
n110 = stb__perlin_grad(stb__perlin_randtab_grad_idx[r11+z0], x-1, y-1, z );
n111 = stb__perlin_grad(stb__perlin_randtab_grad_idx[r11+z1], x-1, y-1, z-1 );
n00 = stb__perlin_lerp(n000,n001,w);
n01 = stb__perlin_lerp(n010,n011,w);
@ -253,7 +254,12 @@ 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, unsigned char seed)
float stb_perlin_noise3(float x, float y, float z, int x_wrap, int y_wrap, int z_wrap)
{
return stb_perlin_noise3_internal(x,y,z,x_wrap,y_wrap,z_wrap,0);
}
float stb_perlin_ridge_noise3(float x, float y, float z, float lacunarity, float gain, float offset, int octaves)
{
int i;
float frequency = 1.0f;
@ -262,19 +268,18 @@ 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 = stb_perlin_noise3(x*frequency,y*frequency,z*frequency,0,0,0,seed);
float r = stb_perlin_noise3_internal(x*frequency,y*frequency,z*frequency,0,0,0,(unsigned char)i);
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, unsigned char seed)
float stb_perlin_fbm_noise3(float x, float y, float z, float lacunarity, float gain, int octaves)
{
int i;
float frequency = 1.0f;
@ -282,15 +287,14 @@ float stb_perlin_fbm_noise3(float x, float y, float z, float lacunarity, float g
float sum = 0.0f;
for (i = 0; i < octaves; i++) {
sum += stb_perlin_noise3(x*frequency,y*frequency,z*frequency,0,0,0,seed)*amplitude;
sum += stb_perlin_noise3_internal(x*frequency,y*frequency,z*frequency,0,0,0,(unsigned char)i)*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, unsigned char seed)
float stb_perlin_turbulence_noise3(float x, float y, float z, float lacunarity, float gain, int octaves)
{
int i;
float frequency = 1.0f;
@ -298,11 +302,10 @@ 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,0,0,0,seed)*amplitude;
float r = stb_perlin_noise3_internal(x*frequency,y*frequency,z*frequency,0,0,0,(unsigned char)i)*amplitude;
sum += fabs(r);
frequency *= lacunarity;
amplitude *= gain;
seed++;
}
return sum;
}

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