public float GetInterpolated(float3 coords)
{
coords /= Spacing; // from [0, 1] to [0, dim - 1]
float3 coord_grid = coords;
float3 index = coord_grid.Floor();
float result = 0.0f;
int MinX = Math.Max(0, (int)index.X - 1), MaxX = Math.Min((int)index.X + 2, Dimensions.X - 1);
int MinY = Math.Max(0, (int)index.Y - 1), MaxY = Math.Min((int)index.Y + 2, Dimensions.Y - 1);
int MinZ = Math.Max(0, (int)index.Z - 1), MaxZ = Math.Min((int)index.Z + 2, Dimensions.Z - 1);
float[,] InterpX = new float[MaxZ - MinZ + 1, MaxY - MinY + 1];
for (int z = MinZ; z <= MaxZ; z++)
{
for (int y = MinY; y <= MaxY; y++)
{
float2[] Points = new float2[MaxX - MinX + 1];
if (Points.Length == 1)
{
InterpX[z - MinZ, y - MinY] = Values[z, y, 0];
}
else
{
for (int x = MinX; x <= MaxX; x++)
{
Points[x - MinX] = new float2(x, Values[z, y, x]);
}
Cubic1DShort Spline = Cubic1DShort.GetInterpolator(Points);
InterpX[z - MinZ, y - MinY] = Spline.Interp(coords.X);
}
}
}
float[] InterpXY = new float[MaxZ - MinZ + 1];
for (int z = MinZ; z <= MaxZ; z++)
{
float2[] Points = new float2[MaxY - MinY + 1];
if (Points.Length == 1)
{
InterpXY[z - MinZ] = InterpX[z - MinZ, 0];
}
else
{
for (int y = MinY; y <= MaxY; y++)
{
Points[y - MinY] = new float2(y, InterpX[z - MinZ, y - MinY]);
}
Cubic1DShort Spline = Cubic1DShort.GetInterpolator(Points);
InterpXY[z - MinZ] = Spline.Interp(coords.Y);
}
}
{
float2[] Points = new float2[MaxZ - MinZ + 1];
if (Points.Length == 1)
{
result = InterpXY[0];
}
else
{
for (int z = MinZ; z <= MaxZ; z++)
{
Points[z - MinZ] = new float2(z, InterpXY[z - MinZ]);
}
Cubic1DShort Spline = Cubic1DShort.GetInterpolator(Points);
result = Spline.Interp(coords.Z);
}
}
return(result);
}
