/// <summary>
/// Returns a grid point at the given point.
/// Assumes the point is within the bounds of the grid.
/// </summary>
/// <param name="point"></param>
/// <param name="result"></param>
public void GridPointAtUnchecked(Vec3d point, GridPoint3d result)
{
point = ToGridSpace(point);
result.SetWeights(
SlurMath.Fract(point.X, out int i0),
SlurMath.Fract(point.Y, out int j0),
SlurMath.Fract(point.Z, out int k0)
);
j0 *= _nx;
k0 *= _nxy;
int i1 = i0 + 1;
int j1 = j0 + _nx;
int k1 = k0 + _nxy;
var corners = result.Corners;
corners[0] = i0 + j0 + k0;
corners[1] = i1 + j0 + k0;
corners[2] = i0 + j1 + k0;
corners[3] = i1 + j1 + k0;
corners[4] = i0 + j0 + k1;
corners[5] = i1 + j0 + k1;
corners[6] = i0 + j1 + k1;
corners[7] = i1 + j1 + k1;
}
/// <summary>
/// Returns the noise value at the given coordinates.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public static double ValueAt(double x, double y)
{
// separate whole and fractional components
x = SlurMath.Fract(x, out int i);
y = SlurMath.Fract(y, out int j);
// wrap to perm table
i &= 255;
j &= 255;
// calculate noise contributions from each corner
double n00 = GradDot(ToIndex(i, j), x, y);
double n10 = GradDot(ToIndex(i + 1, j), x - 1.0, y);
double n01 = GradDot(ToIndex(i, j + 1), x, y - 1.0);
double n11 = GradDot(ToIndex(i + 1, j + 1), x - 1.0, y - 1.0);
// eased values for x and y
x = SlurMath.HermiteC2(x);
y = SlurMath.HermiteC2(y);
// bilinear interpolation
return(SlurMath.Lerp(
SlurMath.Lerp(n00, n10, x),
SlurMath.Lerp(n01, n11, x),
y));
}
/// <inheritdoc />
protected sealed override double ValueAtLinear(Vec3d point)
{
point = ToGridSpace(point);
double u = SlurMath.Fract(point.X, out int i0);
double v = SlurMath.Fract(point.Y, out int j0);
double w = SlurMath.Fract(point.Z, out int k0);
int i1 = WrapX(i0 + 1);
int j1 = WrapY(j0 + 1) * CountX;
int k1 = WrapZ(k0 + 1) * CountXY;
i0 = WrapX(i0);
j0 = WrapY(j0) * CountX;
k0 = WrapZ(k0) * CountXY;
var vals = Values;
return(SlurMath.Lerp(
SlurMath.Lerp(
SlurMath.Lerp(vals[i0 + j0 + k0], vals[i1 + j0 + k0], u),
SlurMath.Lerp(vals[i0 + j1 + k0], vals[i1 + j1 + k0], u),
v),
SlurMath.Lerp(
SlurMath.Lerp(vals[i0 + j0 + k1], vals[i1 + j0 + k1], u),
SlurMath.Lerp(vals[i0 + j1 + k1], vals[i1 + j1 + k1], u),
v),
w));
}
/// <summary>
/// Returns a grid point at the given point.
/// </summary>
/// <param name="point"></param>
/// <param name="result"></param>
public void GridPointAt(Vec3d point, GridPoint3d result)
{
point = ToGridSpace(point);
result.SetWeights(
SlurMath.Fract(point.X, out int i0),
SlurMath.Fract(point.Y, out int j0),
SlurMath.Fract(point.Z, out int k0)
);
int i1 = WrapX(i0 + 1);
int j1 = WrapY(j0 + 1) * _nx;
int k1 = WrapZ(k0 + 1) * _nxy;
i0 = WrapX(i0);
j0 = WrapY(j0) * _nx;
k0 = WrapZ(k0) * _nxy;
var corners = result.Corners;
corners[0] = i0 + j0 + k0;
corners[1] = i1 + j0 + k0;
corners[2] = i0 + j1 + k0;
corners[3] = i1 + j1 + k0;
corners[4] = i0 + j0 + k1;
corners[5] = i1 + j0 + k1;
corners[6] = i0 + j1 + k1;
corners[7] = i1 + j1 + k1;
}
/// <summary>
/// Returns the noise value at the given coordinates
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="z"></param>
/// <returns></returns>
public static double ValueAt(double x, double y, double z)
{
// separate whole and fractional components
x = SlurMath.Fract(x, out int i);
y = SlurMath.Fract(y, out int j);
z = SlurMath.Fract(z, out int k);
// calculate noise contributions from each corner
double n000 = GradDot(ToIndex(i, j, k), x, y, z);
double n100 = GradDot(ToIndex(i + 1, j, k), x - 1.0, y, z);
double n010 = GradDot(ToIndex(i, j + 1, k), x, y - 1.0, z);
double n110 = GradDot(ToIndex(i + 1, j + 1, k), x - 1.0, y - 1.0, z);
double n001 = GradDot(ToIndex(i, j, k + 1), x, y, z - 1.0);
double n101 = GradDot(ToIndex(i + 1, j, k + 1), x - 1.0, y, z - 1.0);
double n011 = GradDot(ToIndex(i, j + 1, k + 1), x, y - 1.0, z - 1.0);
double n111 = GradDot(ToIndex(i + 1, j + 1, k + 1), x - 1.0, y - 1.0, z - 1.0);
// eased values for each dimension
x = SlurMath.HermiteC2(x);
y = SlurMath.HermiteC2(y);
z = SlurMath.HermiteC2(z);
// trilinear interpolation
return(SlurMath.Lerp(
SlurMath.Lerp(
SlurMath.Lerp(n000, n100, x),
SlurMath.Lerp(n010, n110, x),
y),
SlurMath.Lerp(
SlurMath.Lerp(n001, n101, x),
SlurMath.Lerp(n011, n111, x),
y),
z));
}
/// <inheritdoc />
protected sealed override double ValueAtLinearUnsafe(Vec3d point)
{
point = ToGridSpace(point);
double u = SlurMath.Fract(point.X, out int i0);
double v = SlurMath.Fract(point.Y, out int j0);
double w = SlurMath.Fract(point.Z, out int k0);
j0 *= CountX;
k0 *= CountXY;
int i1 = i0 + 1;
int j1 = j0 + CountX;
int k1 = k0 + CountXY;
var vals = Values;
return(SlurMath.Lerp(
SlurMath.Lerp(
SlurMath.Lerp(vals[i0 + j0 + k0], vals[i1 + j0 + k0], u),
SlurMath.Lerp(vals[i0 + j1 + k0], vals[i1 + j1 + k0], u),
v),
SlurMath.Lerp(
SlurMath.Lerp(vals[i0 + j0 + k1], vals[i1 + j0 + k1], u),
SlurMath.Lerp(vals[i0 + j1 + k1], vals[i1 + j1 + k1], u),
v),
w));
}
/// <inheritdoc/>
/// <summary>
///
/// </summary>
/// <param name="point"></param>
/// <returns></returns>
protected sealed override double ValueAtLinearUnchecked(Vec2d point)
{
point = ToGridSpace(point);
double u = SlurMath.Fract(point.X, out int i0);
double v = SlurMath.Fract(point.Y, out int j0);
j0 *= CountX;
int i1 = i0 + 1;
int j1 = j0 + CountX;
var vals = Values;
return(SlurMath.Lerp(
SlurMath.Lerp(vals[i0 + j0], vals[i1 + j0], u),
SlurMath.Lerp(vals[i0 + j1], vals[i1 + j1], u),
v));
}
/// <inheritdoc />
protected sealed override Vec2d ValueAtLinear(Vec2d point)
{
point = ToGridSpace(point);
double u = SlurMath.Fract(point.X, out int i0);
double v = SlurMath.Fract(point.Y, out int j0);
int i1 = WrapX(i0 + 1);
int j1 = WrapY(j0 + 1) * CountX;
i0 = WrapX(i0);
j0 = WrapY(j0) * CountX;
var vals = Values;
return(Vec2d.Lerp(
Vec2d.Lerp(vals[i0 + j0], vals[i1 + j0], u),
Vec2d.Lerp(vals[i0 + j1], vals[i1 + j1], u),
v));
}
/// <summary>
/// Returns a grid point at the given point.
/// Assumes the point is within the bounds of the grid.
/// </summary>
/// <param name="point"></param>
/// <param name="result"></param>
public void GridPointAtUnsafe(Vec2d point, GridPoint2d result)
{
point = ToGridSpace(point);
result.SetWeights(
SlurMath.Fract(point.X, out int i0),
SlurMath.Fract(point.Y, out int j0)
);
j0 *= _nx;
int i1 = i0 + 1;
int j1 = j0 + _nx;
var corners = result.Corners;
corners[0] = i0 + j0;
corners[1] = i1 + j0;
corners[2] = i0 + j1;
corners[3] = i1 + j1;
}
/// <summary>
/// TODO move into SlurUnity
/// </summary>
/// <param name="colors"></param>
/// <param name="factor"></param>
/// <returns></returns>
public static Color Lerp(IReadOnlyList <Color> colors, float factor)
{
int last = colors.Count - 1;
int i;
// object SlurMathf = null;
factor = SlurMath.Fract(factor * last, out i);
//Fract(factor * last, out i);
if (i < 0)
{
return(colors[0]);
}
else if (i >= last)
{
return(colors[last]);
}
return(Color.LerpUnclamped(colors[i], colors[i + 1], factor));
}
/// <summary>
/// Returns a grid point at the given point.
/// </summary>
/// <param name="point"></param>
/// <param name="result"></param>
public void GridPointAt(Vec2d point, GridPoint2d result)
{
point = ToGridSpace(point);
result.SetWeights(
SlurMath.Fract(point.X, out int i0),
SlurMath.Fract(point.Y, out int j0)
);
int i1 = WrapX(i0 + 1);
int j1 = WrapY(j0 + 1) * _nx;
i0 = WrapX(i0);
j0 = WrapY(j0) * _nx;
var corners = result.Corners;
corners[0] = i0 + j0;
corners[1] = i1 + j0;
corners[2] = i0 + j1;
corners[3] = i1 + j1;
}