public double GetValue(double x, double y, double z)
{
if (SourceModule == null)
throw new NullReferenceException();
// Get the values from the three noise::module::Perlin noise modules and
// add each value to each coordinate of the input value. There are also
// some offsets added to the coordinates of the input values. This prevents
// the distortion modules from returning zero if the (x, y, z) coordinates,
// when multiplied by the frequency, are near an integer boundary. This is
// due to a property of gradient coherent noise, which returns zero at
// integer boundaries.
double x0, y0, z0;
double x1, y1, z1;
double x2, y2, z2;
x0 = x + (12414.0 / 65536.0);
y0 = y + (65124.0 / 65536.0);
z0 = z + (31337.0 / 65536.0);
x1 = x + (26519.0 / 65536.0);
y1 = y + (18128.0 / 65536.0);
z1 = z + (60493.0 / 65536.0);
x2 = x + (53820.0 / 65536.0);
y2 = y + (11213.0 / 65536.0);
z2 = z + (44845.0 / 65536.0);
double xDistort = x + (XDistort.GetValue(x0, y0, z0)
* Power);
double yDistort = y + (YDistort.GetValue(x1, y1, z1)
* Power);
double zDistort = z + (ZDistort.GetValue(x2, y2, z2)
* Power);
// Retrieve the output value at the offsetted input value instead of the
// original input value.
return SourceModule.GetValue(xDistort, yDistort, zDistort);
}
