/// <summary>
/// 双线性插值
/// @---->*<--@
/// ↓
/// #
/// ↑
/// @---->*<--@
/// </summary>
/// <returns></returns>
private float _Lerp2D(uint x1, uint y1, uint x2, uint y2, float tx, float ty)
{
tx = RMGUtility.SmoothCurve(tx);
ty = RMGUtility.SmoothCurve(ty);
return(RMGUtility.Lerp(
RMGUtility.Lerp(_permutaion[x1, y1], _permutaion[x2, y1], tx),
RMGUtility.Lerp(_permutaion[x1, y2], _permutaion[x2, y2], tx),
ty));
}
/// <summary>
/// 1D coherent noise
/// </summary>
public float GetPixel(float x)
{
x = Mathf.Min(_to, x);
x = Mathf.Max(_from, x);
x -= _from;
x *= _scale;
// 整数
if ((ushort)x == x)
{
return(_permutation[(ushort)x]);
}
int left = Mathf.FloorToInt(x);
int right = Mathf.CeilToInt(x);
float t = RMGUtility.SmoothCurve(x - left);
return(RMGUtility.Lerp(_permutation[left], _permutation[right], t));
}
