/// <summary>
/// Interpolates between two values using a cubic equation.
/// </summary>
/// <param name="value1">Source value.</param>
/// <param name="value2">Source value.</param>
/// <param name="amount">Weighting value.</param>
/// <returns>Interpolated value.</returns>
public static double SmoothStep(double value1, double value2, double amount)
{
/* It is expected that 0 < amount < 1.
* If amount < 0, return value1.
* If amount > 1, return value2.
*/
double result = MathHelperD.Clamp(amount, 0f, 1f);
result = MathHelperD.Hermite(value1, 0f, value2, 0f, result);
return(result);
}
/// <summary>
/// Creates a new <see cref="Vector2D"/> that contains hermite spline interpolation.
/// </summary>
/// <param name="value1">The first position vector.</param>
/// <param name="tangent1">The first tangent vector.</param>
/// <param name="value2">The second position vector.</param>
/// <param name="tangent2">The second tangent vector.</param>
/// <param name="amount">Weighting factor.</param>
/// <param name="result">The hermite spline interpolation vector as an output parameter.</param>
public static void Hermite(
ref Vector2D value1,
ref Vector2D tangent1,
ref Vector2D value2,
ref Vector2D tangent2,
double amount,
out Vector2D result
)
{
result.X = MathHelperD.Hermite(value1.X, tangent1.X, value2.X, tangent2.X, amount);
result.Y = MathHelperD.Hermite(value1.Y, tangent1.Y, value2.Y, tangent2.Y, amount);
}