mirror of
https://github.com/4jcraft/4jcraft.git
synced 2026-04-26 23:43:37 +00:00
458 lines
15 KiB
C++
458 lines
15 KiB
C++
#include "../../Platform/stdafx.h"
|
|
#include "SimplexNoise.h"
|
|
|
|
int SimplexNoise::grad3[12][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}};
|
|
|
|
double SimplexNoise::F2 = 0.5 * (sqrt(3.0) - 1.0);
|
|
double SimplexNoise::G2 = (3.0 - sqrt(3.0)) / 6.0;
|
|
double SimplexNoise::F3 = 1.0 / 3.0;
|
|
double SimplexNoise::G3 = 1.0 / 6.0;
|
|
|
|
SimplexNoise::SimplexNoise() {
|
|
Random random;
|
|
init(&random);
|
|
}
|
|
|
|
SimplexNoise::SimplexNoise(Random* random) { init(random); }
|
|
|
|
void SimplexNoise::init(Random* random) {
|
|
p = new int[512];
|
|
|
|
xo = random->nextDouble() * 256;
|
|
yo = random->nextDouble() * 256;
|
|
zo = random->nextDouble() * 256;
|
|
for (int i = 0; i < 256; i++) {
|
|
p[i] = i;
|
|
}
|
|
|
|
for (int i = 0; i < 256; i++) {
|
|
int j = random->nextInt(256 - i) + i;
|
|
int tmp = p[i];
|
|
p[i] = p[j];
|
|
p[j] = tmp;
|
|
|
|
p[i + 256] = p[i];
|
|
}
|
|
}
|
|
|
|
SimplexNoise::~SimplexNoise() { delete[] p; }
|
|
|
|
int SimplexNoise::fastfloor(double x) { return x > 0 ? (int)x : (int)x - 1; }
|
|
|
|
double SimplexNoise::dot(int* g, double x, double y) {
|
|
return g[0] * x + g[1] * y;
|
|
}
|
|
|
|
double SimplexNoise::dot(int* g, double x, double y, double z) {
|
|
return g[0] * x + g[1] * y + g[2] * z;
|
|
}
|
|
|
|
double SimplexNoise::getValue(double xin, double yin) {
|
|
double n0, n1, n2; // Noise contributions from the three corners
|
|
// Skew the input space to determine which simplex cell we're in
|
|
double s = (xin + yin) * F2; // Hairy factor for 2D
|
|
int i = fastfloor(xin + s);
|
|
int j = fastfloor(yin + s);
|
|
double t = (i + j) * G2;
|
|
double X0 = i - t; // Unskew the cell origin back to (x,y) space
|
|
double Y0 = j - t;
|
|
double x0 = xin - X0; // The x,y distances from the cell origin
|
|
double y0 = yin - Y0;
|
|
// For the 2D case, the simplex shape is an equilateral triangle.
|
|
// Determine which simplex we are in.
|
|
int i1,
|
|
j1; // Offsets for second (middle) corner of simplex in (i,j) coords
|
|
if (x0 > y0) {
|
|
i1 = 1;
|
|
j1 = 0;
|
|
} // lower triangle, XY order: (0,0)->(1,0)->(1,1)
|
|
else {
|
|
i1 = 0;
|
|
j1 = 1;
|
|
} // upper triangle, YX order: (0,0)->(0,1)->(1,1)
|
|
// A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and
|
|
// a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where
|
|
// c = (3-sqrt(3))/6
|
|
double x1 =
|
|
x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords
|
|
double y1 = y0 - j1 + G2;
|
|
double x2 = x0 - 1.0 +
|
|
2.0 * G2; // Offsets for last corner in (x,y) unskewed coords
|
|
double y2 = y0 - 1.0 + 2.0 * G2;
|
|
// Work out the hashed gradient indices of the three simplex corners
|
|
int ii = i & 255;
|
|
int jj = j & 255;
|
|
int gi0 = p[ii + p[jj]] % 12;
|
|
int gi1 = p[ii + i1 + p[jj + j1]] % 12;
|
|
int gi2 = p[ii + 1 + p[jj + 1]] % 12;
|
|
// Calculate the contribution from the three corners
|
|
double t0 = 0.5 - x0 * x0 - y0 * y0;
|
|
if (t0 < 0)
|
|
n0 = 0.0;
|
|
else {
|
|
t0 *= t0;
|
|
n0 = t0 * t0 *
|
|
dot(grad3[gi0], x0, y0); // (x,y) of grad3 used for 2D gradient
|
|
}
|
|
double t1 = 0.5 - x1 * x1 - y1 * y1;
|
|
if (t1 < 0)
|
|
n1 = 0.0;
|
|
else {
|
|
t1 *= t1;
|
|
n1 = t1 * t1 * dot(grad3[gi1], x1, y1);
|
|
}
|
|
double t2 = 0.5 - x2 * x2 - y2 * y2;
|
|
if (t2 < 0)
|
|
n2 = 0.0;
|
|
else {
|
|
t2 *= t2;
|
|
n2 = t2 * t2 * dot(grad3[gi2], x2, y2);
|
|
}
|
|
// Add contributions from each corner to get the final noise value.
|
|
// The result is scaled to return values in the interval [-1,1].
|
|
return 70.0 * (n0 + n1 + n2);
|
|
}
|
|
|
|
double SimplexNoise::getValue(double xin, double yin, double zin) {
|
|
double n0, n1, n2, n3;
|
|
double s = (xin + yin + zin) * F3;
|
|
int i = fastfloor(xin + s);
|
|
int j = fastfloor(yin + s);
|
|
int k = fastfloor(zin + s);
|
|
|
|
double t = (i + j + k) * G3;
|
|
double X0 = i - t;
|
|
double Y0 = j - t;
|
|
double Z0 = k - t;
|
|
double x0 = xin - X0;
|
|
double y0 = yin - Y0;
|
|
double z0 = zin - Z0;
|
|
int i1, j1, k1;
|
|
int i2, j2, k2;
|
|
if (x0 >= y0) {
|
|
if (y0 >= z0) {
|
|
i1 = 1;
|
|
j1 = 0;
|
|
k1 = 0;
|
|
i2 = 1;
|
|
j2 = 1;
|
|
k2 = 0;
|
|
} // X Y Z order
|
|
else if (x0 >= z0) {
|
|
i1 = 1;
|
|
j1 = 0;
|
|
k1 = 0;
|
|
i2 = 1;
|
|
j2 = 0;
|
|
k2 = 1;
|
|
} // X Z Y order
|
|
else {
|
|
i1 = 0;
|
|
j1 = 0;
|
|
k1 = 1;
|
|
i2 = 1;
|
|
j2 = 0;
|
|
k2 = 1;
|
|
} // Z X Y order
|
|
} else { // x0<y0
|
|
if (y0 < z0) {
|
|
i1 = 0;
|
|
j1 = 0;
|
|
k1 = 1;
|
|
i2 = 0;
|
|
j2 = 1;
|
|
k2 = 1;
|
|
} // Z Y X order
|
|
else if (x0 < z0) {
|
|
i1 = 0;
|
|
j1 = 1;
|
|
k1 = 0;
|
|
i2 = 0;
|
|
j2 = 1;
|
|
k2 = 1;
|
|
} // Y Z X order
|
|
else {
|
|
i1 = 0;
|
|
j1 = 1;
|
|
k1 = 0;
|
|
i2 = 1;
|
|
j2 = 1;
|
|
k2 = 0;
|
|
} // Y X Z order
|
|
}
|
|
// A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z),
|
|
// a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and
|
|
// a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z),
|
|
// where c = 1/6.
|
|
|
|
double x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords
|
|
double y1 = y0 - j1 + G3;
|
|
double z1 = z0 - k1 + G3;
|
|
double x2 =
|
|
x0 - i2 + 2.0 * G3; // Offsets for third corner in (x,y,z) coords
|
|
double y2 = y0 - j2 + 2.0 * G3;
|
|
double z2 = z0 - k2 + 2.0 * G3;
|
|
double x3 =
|
|
x0 - 1.0 + 3.0 * G3; // Offsets for last corner in (x,y,z) coords
|
|
double y3 = y0 - 1.0 + 3.0 * G3;
|
|
double z3 = z0 - 1.0 + 3.0 * G3;
|
|
// Work out the hashed gradient indices of the four simplex corners
|
|
int ii = i & 255;
|
|
int jj = j & 255;
|
|
int kk = k & 255;
|
|
int gi0 = p[ii + p[jj + p[kk]]] % 12;
|
|
int gi1 = p[ii + i1 + p[jj + j1 + p[kk + k1]]] % 12;
|
|
int gi2 = p[ii + i2 + p[jj + j2 + p[kk + k2]]] % 12;
|
|
int gi3 = p[ii + 1 + p[jj + 1 + p[kk + 1]]] % 12;
|
|
// Calculate the contribution from the four corners
|
|
double t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0;
|
|
if (t0 < 0)
|
|
n0 = 0.0;
|
|
else {
|
|
t0 *= t0;
|
|
n0 = t0 * t0 * dot(grad3[gi0], x0, y0, z0);
|
|
}
|
|
double t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1;
|
|
if (t1 < 0)
|
|
n1 = 0.0;
|
|
else {
|
|
t1 *= t1;
|
|
n1 = t1 * t1 * dot(grad3[gi1], x1, y1, z1);
|
|
}
|
|
double t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2;
|
|
if (t2 < 0)
|
|
n2 = 0.0;
|
|
else {
|
|
t2 *= t2;
|
|
n2 = t2 * t2 * dot(grad3[gi2], x2, y2, z2);
|
|
}
|
|
double t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3;
|
|
if (t3 < 0)
|
|
n3 = 0.0;
|
|
else {
|
|
t3 *= t3;
|
|
n3 = t3 * t3 * dot(grad3[gi3], x3, y3, z3);
|
|
}
|
|
// Add contributions from each corner to get the final noise value.
|
|
// The result is scaled to stay just inside [-1,1]
|
|
return 32.0 * (n0 + n1 + n2 + n3);
|
|
}
|
|
|
|
void SimplexNoise::add(doubleArray buffer, double _x, double _y, int xSize,
|
|
int ySize, double xs, double ys, double pow) {
|
|
int pp = 0;
|
|
for (int xx = 0; xx < xSize; xx++) {
|
|
double xin = (_x + xx) * xs + xo;
|
|
for (int yy = 0; yy < ySize; yy++) {
|
|
double yin = (_y + yy) * ys + yo;
|
|
|
|
double n0, n1, n2;
|
|
double s = (xin + yin) * F2; // Hairy factor for 2D
|
|
int i = fastfloor(xin + s);
|
|
int j = fastfloor(yin + s);
|
|
double t = (i + j) * G2;
|
|
double X0 = i - t; // Unskew the cell origin back to (x,y) space
|
|
double Y0 = j - t;
|
|
double x0 = xin - X0; // The x,y distances from the cell origin
|
|
double y0 = yin - Y0;
|
|
// For the 2D case, the simplex shape is an equilateral triangle.
|
|
// Determine which simplex we are in.
|
|
int i1, j1; // Offsets for second (middle) corner of simplex in
|
|
// (i,j) coords
|
|
if (x0 > y0) {
|
|
i1 = 1;
|
|
j1 = 0;
|
|
} // lower triangle, XY order: (0,0)->(1,0)->(1,1)
|
|
else {
|
|
i1 = 0;
|
|
j1 = 1;
|
|
} // upper triangle, YX order: (0,0)->(0,1)->(1,1)
|
|
// A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and
|
|
// a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where
|
|
// c = (3-sqrt(3))/6
|
|
double x1 =
|
|
x0 - i1 +
|
|
G2; // Offsets for middle corner in (x,y) unskewed coords
|
|
double y1 = y0 - j1 + G2;
|
|
double x2 =
|
|
x0 - 1.0 +
|
|
2.0 * G2; // Offsets for last corner in (x,y) unskewed coords
|
|
double y2 = y0 - 1.0 + 2.0 * G2;
|
|
// Work out the hashed gradient indices of the three simplex corners
|
|
int ii = i & 255;
|
|
int jj = j & 255;
|
|
int gi0 = p[ii + p[jj]] % 12;
|
|
int gi1 = p[ii + i1 + p[jj + j1]] % 12;
|
|
int gi2 = p[ii + 1 + p[jj + 1]] % 12;
|
|
// Calculate the contribution from the three corners
|
|
double t0 = 0.5 - x0 * x0 - y0 * y0;
|
|
if (t0 < 0)
|
|
n0 = 0.0;
|
|
else {
|
|
t0 *= t0;
|
|
n0 = t0 * t0 *
|
|
dot(grad3[gi0], x0,
|
|
y0); // (x,y) of grad3 used for 2D gradient
|
|
}
|
|
double t1 = 0.5 - x1 * x1 - y1 * y1;
|
|
if (t1 < 0)
|
|
n1 = 0.0;
|
|
else {
|
|
t1 *= t1;
|
|
n1 = t1 * t1 * dot(grad3[gi1], x1, y1);
|
|
}
|
|
double t2 = 0.5 - x2 * x2 - y2 * y2;
|
|
if (t2 < 0)
|
|
n2 = 0.0;
|
|
else {
|
|
t2 *= t2;
|
|
n2 = t2 * t2 * dot(grad3[gi2], x2, y2);
|
|
}
|
|
// Add contributions from each corner to get the final noise value.
|
|
// The result is scaled to return values in the interval [-1,1].
|
|
buffer[pp++] += (70.0 * (n0 + n1 + n2)) * pow;
|
|
}
|
|
}
|
|
}
|
|
void SimplexNoise::add(doubleArray buffer, double _x, double _y, double _z,
|
|
int xSize, int ySize, int zSize, double xs, double ys,
|
|
double zs, double pow) {
|
|
int pp = 0;
|
|
for (int xx = 0; xx < xSize; xx++) {
|
|
double xin = (_x + xx) * xs + xo;
|
|
for (int zz = 0; zz < zSize; zz++) {
|
|
double zin = (_z + zz) * zs + zo;
|
|
for (int yy = 0; yy < ySize; yy++) {
|
|
double yin = (_y + yy) * ys + yo;
|
|
|
|
double n0, n1, n2, n3;
|
|
double s = (xin + yin + zin) * F3;
|
|
int i = fastfloor(xin + s);
|
|
int j = fastfloor(yin + s);
|
|
int k = fastfloor(zin + s);
|
|
double t = (i + j + k) * G3;
|
|
double X0 = i - t;
|
|
double Y0 = j - t;
|
|
double Z0 = k - t;
|
|
double x0 = xin - X0;
|
|
double y0 = yin - Y0;
|
|
double z0 = zin - Z0;
|
|
int i1, j1, k1;
|
|
int i2, j2, k2;
|
|
if (x0 >= y0) {
|
|
if (y0 >= z0) {
|
|
i1 = 1;
|
|
j1 = 0;
|
|
k1 = 0;
|
|
i2 = 1;
|
|
j2 = 1;
|
|
k2 = 0;
|
|
} // X Y Z order
|
|
else if (x0 >= z0) {
|
|
i1 = 1;
|
|
j1 = 0;
|
|
k1 = 0;
|
|
i2 = 1;
|
|
j2 = 0;
|
|
k2 = 1;
|
|
} // X Z Y order
|
|
else {
|
|
i1 = 0;
|
|
j1 = 0;
|
|
k1 = 1;
|
|
i2 = 1;
|
|
j2 = 0;
|
|
k2 = 1;
|
|
} // Z X Y order
|
|
} else { // x0<y0
|
|
if (y0 < z0) {
|
|
i1 = 0;
|
|
j1 = 0;
|
|
k1 = 1;
|
|
i2 = 0;
|
|
j2 = 1;
|
|
k2 = 1;
|
|
} // Z Y X order
|
|
else if (x0 < z0) {
|
|
i1 = 0;
|
|
j1 = 1;
|
|
k1 = 0;
|
|
i2 = 0;
|
|
j2 = 1;
|
|
k2 = 1;
|
|
} // Y Z X order
|
|
else {
|
|
i1 = 0;
|
|
j1 = 1;
|
|
k1 = 0;
|
|
i2 = 1;
|
|
j2 = 1;
|
|
k2 = 0;
|
|
} // Y X Z order
|
|
}
|
|
// A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in
|
|
// (x,y,z), a step of (0,1,0) in (i,j,k) means a step of
|
|
// (-c,1-c,-c) in (x,y,z), and a step of (0,0,1) in (i,j,k)
|
|
// means a step of (-c,-c,1-c) in (x,y,z), where c = 1/6.
|
|
|
|
double x1 = x0 - i1 +
|
|
G3; // Offsets for second corner in (x,y,z) coords
|
|
double y1 = y0 - j1 + G3;
|
|
double z1 = z0 - k1 + G3;
|
|
double x2 =
|
|
x0 - i2 +
|
|
2.0 * G3; // Offsets for third corner in (x,y,z) coords
|
|
double y2 = y0 - j2 + 2.0 * G3;
|
|
double z2 = z0 - k2 + 2.0 * G3;
|
|
double x3 =
|
|
x0 - 1.0 +
|
|
3.0 * G3; // Offsets for last corner in (x,y,z) coords
|
|
double y3 = y0 - 1.0 + 3.0 * G3;
|
|
double z3 = z0 - 1.0 + 3.0 * G3;
|
|
// Work out the hashed gradient indices of the four simplex
|
|
// corners
|
|
int ii = i & 255;
|
|
int jj = j & 255;
|
|
int kk = k & 255;
|
|
int gi0 = p[ii + p[jj + p[kk]]] % 12;
|
|
int gi1 = p[ii + i1 + p[jj + j1 + p[kk + k1]]] % 12;
|
|
int gi2 = p[ii + i2 + p[jj + j2 + p[kk + k2]]] % 12;
|
|
int gi3 = p[ii + 1 + p[jj + 1 + p[kk + 1]]] % 12;
|
|
// Calculate the contribution from the four corners
|
|
double t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0;
|
|
if (t0 < 0)
|
|
n0 = 0.0;
|
|
else {
|
|
t0 *= t0;
|
|
n0 = t0 * t0 * dot(grad3[gi0], x0, y0, z0);
|
|
}
|
|
double t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1;
|
|
if (t1 < 0)
|
|
n1 = 0.0;
|
|
else {
|
|
t1 *= t1;
|
|
n1 = t1 * t1 * dot(grad3[gi1], x1, y1, z1);
|
|
}
|
|
double t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2;
|
|
if (t2 < 0)
|
|
n2 = 0.0;
|
|
else {
|
|
t2 *= t2;
|
|
n2 = t2 * t2 * dot(grad3[gi2], x2, y2, z2);
|
|
}
|
|
double t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3;
|
|
if (t3 < 0)
|
|
n3 = 0.0;
|
|
else {
|
|
t3 *= t3;
|
|
n3 = t3 * t3 * dot(grad3[gi3], x3, y3, z3);
|
|
}
|
|
// Add contributions from each corner to get the final noise
|
|
// value. The result is scaled to stay just inside [-1,1]
|
|
buffer[pp++] += (32.0 * (n0 + n1 + n2 + n3)) * pow;
|
|
}
|
|
}
|
|
}
|
|
} |