public override double GetValue(double x, double y, double z)
{
x *= Frequency;
y *= Frequency;
z *= Frequency;
int xInt = (x > 0.0 ? (int)x : (int)x - 1);
int yInt = (y > 0.0 ? (int)y : (int)y - 1);
int zInt = (z > 0.0 ? (int)z : (int)z - 1);
double minDist = 2147483647.0;
double xCandidate = 0;
double yCandidate = 0;
double zCandidate = 0;
// Inside each unit cube, there is a seed point at a random position. Go
// through each of the nearby cubes until we find a cube with a seed point
// that is closest to the specified position.
for (int zCur = zInt - 2; zCur <= zInt + 2; zCur++)
{
for (int yCur = yInt - 2; yCur <= yInt + 2; yCur++)
{
for (int xCur = xInt - 2; xCur <= xInt + 2; xCur++)
{
// Calculate the position and distance to the seed point inside of
// this unit cube.
double xPos = xCur + GeneratorBase.ValueNoise(xCur, yCur, zCur, Seed);
double yPos = yCur + GeneratorBase.ValueNoise(xCur, yCur, zCur, Seed + 1);
double zPos = zCur + GeneratorBase.ValueNoise(xCur, yCur, zCur, Seed + 2);
double xDist = xPos - x;
double yDist = yPos - y;
double zDist = zPos - z;
double dist = xDist * xDist + yDist * yDist + zDist * zDist;
if (!(dist < minDist))
{
continue;
}
// This seed point is closer to any others found so far, so record
// this seed point.
minDist = dist;
xCandidate = xPos;
yCandidate = yPos;
zCandidate = zPos;
}
}
}
double value;
if (DistanceEnabled)
{
// Determine the distance to the nearest seed point.
double xDist = xCandidate - x;
double yDist = yCandidate - y;
double zDist = zCandidate - z;
value = (System.Math.Sqrt(xDist * xDist + yDist * yDist + zDist * zDist)
) * NoiseMath.Sqrt3 - 1.0;
}
else
{
value = 0.0;
}
int x0 = (xCandidate > 0.0 ? (int)xCandidate : (int)xCandidate - 1);
int y0 = (yCandidate > 0.0 ? (int)yCandidate : (int)yCandidate - 1);
int z0 = (zCandidate > 0.0 ? (int)zCandidate : (int)zCandidate - 1);
// Return the calculated distance with the displacement value applied.
return(value + (Displacement * GeneratorBase.ValueNoise(x0, y0, z0)));
}