public void SetParameters(double Zoom, InflectionMode inflection, ResultScale scale)
{
_zoom = Zoom;
_inflection = inflection;
_scale = scale;
}
// To remove the need for index wrapping, double the permutation table length
//private static int[] perm = new int[512];
//static { for(int i=0; i<512; i++) perm[i]=p[i & 255]; }
//3D noise
private double noise(double x, double y, double z, ResultScale scale)
{
double n0, n1, n2, n3; // Noise contributions from the four corner
// Skew the input space to determine which simplex cell we're in
const double F3 = 1.0 / 3.0;
double s = (x + y + z) * F3; // Very nice and simple skew factor for 3D
int i = MathHelper.Floor(x + s);
int j = MathHelper.Floor(y + s);
int k = MathHelper.Floor(z + s);
const double G3 = 1.0 / 6.0; // Very nice and simple unskew factor, too
double t = (i + j + k) * G3;
double X0 = i - t; // Unskew the cell origin back to (x,y,z) spac
double Y0 = j - t;
double Z0 = k - t;
double x0 = x - X0; // The x,y,z distances from the cell origin
double y0 = y - Y0;
double z0 = z - Z0;
// For the 3D case, the simplex shape is a slightly irregular tetrahedron.
// Determine which simplex we are in.
int i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords
int i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coord
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 orde
}
else
{
i1 = 0; j1 = 0; k1 = 1; i2 = 1; j2 = 0; k2 = 1; // Z X Y orde
}
}
else
{
if (y0 < z0)
{
i1 = 0; j1 = 0; k1 = 1; i2 = 0; j2 = 1; k2 = 1; // X Y Z order
}
else if (x0 < z0)
{
i1 = 0; j1 = 1; k1 = 0; i2 = 0; j2 = 1; k2 = 1; // X Z Y orde
}
else
{
i1 = 0; j1 = 1; k1 = 0; i2 = 1; j2 = 1; k2 = 0; // Z X Y orde
}
}
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 = perm[ii + perm[jj + perm[kk]]] % 12;
int gi1 = perm[ii + i1 + perm[jj + j1 + perm[kk + k1]]] % 12;
int gi2 = perm[ii + i2 + perm[jj + j2 + perm[kk + k2]]] % 12;
int gi3 = perm[ii + 1 + perm[jj + 1 + perm[kk + 1]]] % 12;
// Calculate the contribution from the four corners
double t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0;
if (t0 < 0)
{
n0 = 0.0f;
}
else
{
t0 *= t0;
n0 = t0 * t0 * MathHelper.Dot(grad3[gi0], ref x0, ref y0, ref z0);
}
double t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1;
if (t1 < 0)
{
n1 = 0.0f;
}
else
{
t1 *= t1;
n1 = t1 * t1 * MathHelper.Dot(grad3[gi1], ref x1, ref y1, ref z1);
}
double t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2;
if (t2 < 0)
{
n2 = 0.0f;
}
else
{
t2 *= t2;
n2 = t2 * t2 * MathHelper.Dot(grad3[gi2], ref x2, ref y2, ref z2);
}
double t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3;
if (t3 < 0)
{
n3 = 0.0f;
}
else
{
t3 *= t3;
n3 = t3 * t3 * MathHelper.Dot(grad3[gi3], ref x3, ref y3, ref z3);
}
if (scale == ResultScale.MinOneToOne)
{
return(32.0 * (n0 + n1 + n2 + n3));
}
else
{
return(16.0 * (n0 + n1 + n2 + n3) + 0.5);
}
}
//2D noise
private double noise(double x, double y, ResultScale scale)
{
double n0, n1, n2; // Noise contributions from the three corner
// Skew the input space to determine which simplex cell we're in
const double F2 = 0.3660254; //0.5*(Math.Sqrt(3.0)-1.0);
double s = (x + y) * F2; // Hairy factor for 2D
int i = MathHelper.Floor(x + s);
int j = MathHelper.Floor(y + s);
const double G2 = 0.2113248; //(3.0-Math.Sqrt(3.0))/6.0;
double t = (i + j) * G2;
double X0 = i - t; // Unskew the cell origin back to (x,y) space
double Y0 = j - t;
double x0 = x - X0; // The x,y distances from the cell origin
double y0 = y - 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 = perm[ii + perm[jj]] % 12;
int gi1 = perm[ii + i1 + perm[jj + j1]] % 12;
int gi2 = perm[ii + 1 + perm[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 * MathHelper.Dot(grad3[gi0], ref x0, ref 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 * MathHelper.Dot(grad3[gi1], ref x1, ref y1);
}
double t2 = 0.5 - x2 * x2 - y2 * y2;
if (t2 < 0)
{
n2 = 0.0;
}
else
{
t2 *= t2;
n2 = t2 * t2 * MathHelper.Dot(grad3[gi2], ref x2, ref y2);
}
// Add contributions from each corner to get the final noise value.
if (scale == ResultScale.MinOneToOne)
{
return(70.0 * (n0 + n1 + n2));
}
if (scale == ResultScale.ZeroToOne)
{
return(35.0 * (n0 + n1 + n2) + 0.5);
}
return(0);
}
