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#include "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 ? static_cast<int>(x) : static_cast<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;
}
}
}
}
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