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CraftNG/deps/noise/noise.c

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/*
https://github.com/fogleman/Craft
noise.h and noise.c are derived from this project:
https://github.com/caseman/noise
Copyright (c) 2008 Casey Duncan
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
#include <math.h>
#include <stdlib.h>
#include <string.h>
#define F2 0.3660254037844386f
#define G2 0.21132486540518713f
#define F3 (1.0f / 3.0f)
#define G3 (1.0f / 6.0f)
#define ASSIGN(a, v0, v1, v2) (a)[0] = v0; (a)[1] = v1; (a)[2] = v2;
#define DOT3(v1, v2) ((v1)[0] * (v2)[0] + (v1)[1] * (v2)[1] + (v1)[2] * (v2)[2])
const static float GRAD3[16][3] = {
{ 1, 1, 0}, {-1, 1, 0}, { 1,-1, 0}, {-1,-1, 0},
{ 1, 0, 1}, {-1, 0, 1}, { 1, 0,-1}, {-1, 0,-1},
{ 0, 1, 1}, { 0,-1, 1}, { 0, 1,-1}, { 0,-1,-1},
{ 1, 0,-1}, {-1, 0,-1}, { 0,-1, 1}, { 0, 1, 1}
};
static unsigned char PERM[] = {
151, 160, 137, 91, 90, 15, 131, 13,
201, 95, 96, 53, 194, 233, 7, 225,
140, 36, 103, 30, 69, 142, 8, 99,
37, 240, 21, 10, 23, 190, 6, 148,
247, 120, 234, 75, 0, 26, 197, 62,
94, 252, 219, 203, 117, 35, 11, 32,
57, 177, 33, 88, 237, 149, 56, 87,
174, 20, 125, 136, 171, 168, 68, 175,
74, 165, 71, 134, 139, 48, 27, 166,
77, 146, 158, 231, 83, 111, 229, 122,
60, 211, 133, 230, 220, 105, 92, 41,
55, 46, 245, 40, 244, 102, 143, 54,
65, 25, 63, 161, 1, 216, 80, 73,
209, 76, 132, 187, 208, 89, 18, 169,
200, 196, 135, 130, 116, 188, 159, 86,
164, 100, 109, 198, 173, 186, 3, 64,
52, 217, 226, 250, 124, 123, 5, 202,
38, 147, 118, 126, 255, 82, 85, 212,
207, 206, 59, 227, 47, 16, 58, 17,
182, 189, 28, 42, 223, 183, 170, 213,
119, 248, 152, 2, 44, 154, 163, 70,
221, 153, 101, 155, 167, 43, 172, 9,
129, 22, 39, 253, 19, 98, 108, 110,
79, 113, 224, 232, 178, 185, 112, 104,
218, 246, 97, 228, 251, 34, 242, 193,
238, 210, 144, 12, 191, 179, 162, 241,
81, 51, 145, 235, 249, 14, 239, 107,
49, 192, 214, 31, 181, 199, 106, 157,
184, 84, 204, 176, 115, 121, 50, 45,
127, 4, 150, 254, 138, 236, 205, 93,
222, 114, 67, 29, 24, 72, 243, 141,
128, 195, 78, 66, 215, 61, 156, 180,
151, 160, 137, 91, 90, 15, 131, 13,
201, 95, 96, 53, 194, 233, 7, 225,
140, 36, 103, 30, 69, 142, 8, 99,
37, 240, 21, 10, 23, 190, 6, 148,
247, 120, 234, 75, 0, 26, 197, 62,
94, 252, 219, 203, 117, 35, 11, 32,
57, 177, 33, 88, 237, 149, 56, 87,
174, 20, 125, 136, 171, 168, 68, 175,
74, 165, 71, 134, 139, 48, 27, 166,
77, 146, 158, 231, 83, 111, 229, 122,
60, 211, 133, 230, 220, 105, 92, 41,
55, 46, 245, 40, 244, 102, 143, 54,
65, 25, 63, 161, 1, 216, 80, 73,
209, 76, 132, 187, 208, 89, 18, 169,
200, 196, 135, 130, 116, 188, 159, 86,
164, 100, 109, 198, 173, 186, 3, 64,
52, 217, 226, 250, 124, 123, 5, 202,
38, 147, 118, 126, 255, 82, 85, 212,
207, 206, 59, 227, 47, 16, 58, 17,
182, 189, 28, 42, 223, 183, 170, 213,
119, 248, 152, 2, 44, 154, 163, 70,
221, 153, 101, 155, 167, 43, 172, 9,
129, 22, 39, 253, 19, 98, 108, 110,
79, 113, 224, 232, 178, 185, 112, 104,
218, 246, 97, 228, 251, 34, 242, 193,
238, 210, 144, 12, 191, 179, 162, 241,
81, 51, 145, 235, 249, 14, 239, 107,
49, 192, 214, 31, 181, 199, 106, 157,
184, 84, 204, 176, 115, 121, 50, 45,
127, 4, 150, 254, 138, 236, 205, 93,
222, 114, 67, 29, 24, 72, 243, 141,
128, 195, 78, 66, 215, 61, 156, 180
};
void seed(unsigned int x) {
srand(x);
for (int i = 0; i < 256; i++) {
PERM[i] = i;
}
for (int i = 255; i > 0; i--) {
int j;
int n = i + 1;
while (n <= (j = rand() / (RAND_MAX / n)));
unsigned char a = PERM[i];
unsigned char b = PERM[j];
PERM[i] = b;
PERM[j] = a;
}
memcpy(PERM + 256, PERM, sizeof(unsigned char) * 256);
}
float noise2(float x, float y) {
int i1, j1, I, J, c;
float s = (x + y) * F2;
float i = floorf(x + s);
float j = floorf(y + s);
float t = (i + j) * G2;
float xx[3], yy[3], f[3];
float noise[3] = {0.0f, 0.0f, 0.0f};
int g[3];
xx[0] = x - (i - t);
yy[0] = y - (j - t);
i1 = xx[0] > yy[0];
j1 = xx[0] <= yy[0];
xx[2] = xx[0] + G2 * 2.0f - 1.0f;
yy[2] = yy[0] + G2 * 2.0f - 1.0f;
xx[1] = xx[0] - i1 + G2;
yy[1] = yy[0] - j1 + G2;
I = (int) i & 255;
J = (int) j & 255;
g[0] = PERM[I + PERM[J]] % 12;
g[1] = PERM[I + i1 + PERM[J + j1]] % 12;
g[2] = PERM[I + 1 + PERM[J + 1]] % 12;
for (c = 0; c <= 2; c++) {
f[c] = 0.5f - xx[c]*xx[c] - yy[c]*yy[c];
}
for (c = 0; c <= 2; c++) {
if (f[c] > 0) {
noise[c] = f[c] * f[c] * f[c] * f[c] *
(GRAD3[g[c]][0] * xx[c] + GRAD3[g[c]][1] * yy[c]);
}
}
return (noise[0] + noise[1] + noise[2]) * 70.0f;
}
float noise3(float x, float y, float z) {
int c, o1[3], o2[3], g[4], I, J, K;
float f[4], noise[4] = {0.0f, 0.0f, 0.0f, 0.0f};
float s = (x + y + z) * F3;
float i = floorf(x + s);
float j = floorf(y + s);
float k = floorf(z + s);
float t = (i + j + k) * G3;
float pos[4][3];
pos[0][0] = x - (i - t);
pos[0][1] = y - (j - t);
pos[0][2] = z - (k - t);
if (pos[0][0] >= pos[0][1]) {
if (pos[0][1] >= pos[0][2]) {
ASSIGN(o1, 1, 0, 0);
ASSIGN(o2, 1, 1, 0);
} else if (pos[0][0] >= pos[0][2]) {
ASSIGN(o1, 1, 0, 0);
ASSIGN(o2, 1, 0, 1);
} else {
ASSIGN(o1, 0, 0, 1);
ASSIGN(o2, 1, 0, 1);
}
} else {
if (pos[0][1] < pos[0][2]) {
ASSIGN(o1, 0, 0, 1);
ASSIGN(o2, 0, 1, 1);
} else if (pos[0][0] < pos[0][2]) {
ASSIGN(o1, 0, 1, 0);
ASSIGN(o2, 0, 1, 1);
} else {
ASSIGN(o1, 0, 1, 0);
ASSIGN(o2, 1, 1, 0);
}
}
for (c = 0; c <= 2; c++) {
pos[3][c] = pos[0][c] - 1.0f + 3.0f * G3;
pos[2][c] = pos[0][c] - o2[c] + 2.0f * G3;
pos[1][c] = pos[0][c] - o1[c] + G3;
}
I = (int) i & 255;
J = (int) j & 255;
K = (int) k & 255;
g[0] = PERM[I + PERM[J + PERM[K]]] % 12;
g[1] = PERM[I + o1[0] + PERM[J + o1[1] + PERM[o1[2] + K]]] % 12;
g[2] = PERM[I + o2[0] + PERM[J + o2[1] + PERM[o2[2] + K]]] % 12;
g[3] = PERM[I + 1 + PERM[J + 1 + PERM[K + 1]]] % 12;
for (c = 0; c <= 3; c++) {
f[c] = 0.6f - pos[c][0] * pos[c][0] - pos[c][1] * pos[c][1] -
pos[c][2] * pos[c][2];
}
for (c = 0; c <= 3; c++) {
if (f[c] > 0) {
noise[c] = f[c] * f[c] * f[c] * f[c] * DOT3(pos[c], GRAD3[g[c]]);
}
}
return (noise[0] + noise[1] + noise[2] + noise[3]) * 32.0f;
}
float simplex2(
float x, float y,
int octaves, float persistence, float lacunarity)
{
float freq = 1.0f;
float amp = 1.0f;
float max = 1.0f;
float total = noise2(x, y);
int i;
for (i = 1; i < octaves; i++) {
freq *= lacunarity;
amp *= persistence;
max += amp;
total += noise2(x * freq, y * freq) * amp;
}
return (1 + total / max) / 2;
}
float simplex3(
float x, float y, float z,
int octaves, float persistence, float lacunarity)
{
float freq = 1.0f;
float amp = 1.0f;
float max = 1.0f;
float total = noise3(x, y, z);
int i;
for (i = 1; i < octaves; ++i) {
freq *= lacunarity;
amp *= persistence;
max += amp;
total += noise3(x * freq, y * freq, z * freq) * amp;
}
return (1 + total / max) / 2;
}
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