public void SingleValue()
{
var c = new HermiteSpline <double> {
{ 0, 5, 0 }
};
Assert.AreEqual(5.0, c[-1]);
Assert.AreEqual(5.0, c[0]);
Assert.AreEqual(5.0, c[1]);
}
/// <summary>
/// Splits a hermite spline at a position.
/// Note that this may produce more than two output splines in order to eliminate discontinuities.
/// </summary>
/// <param name="splitPosition">The position at which to split the spline.</param>
public static HermiteSpline <T>[] Split <T> (
this HermiteSpline <T> spline,
float splitPosition
)
where T : struct
{
var resultList = new List <HermiteSpline <T> >(4);
spline.SplitInto(splitPosition, resultList);
return(resultList.ToArray());
}
public void TwoValues()
{
var c = new HermiteSpline <double> {
{ 0, 5, 0 },
{ 1, 10, 0 }
};
Assert.AreEqual(5.0, c[-1]);
Assert.AreEqual(5.0, c[0]);
Assert.AreEqual(10.0, c[1]);
Assert.AreEqual(10.0, c[2]);
}
public static HermiteSpline <T> Cardinal(IEnumerable <CurvePoint <T> > points, float tension)
{
var result = new HermiteSpline <T>();
foreach (var pt in points)
{
result.Add(pt.Position, pt.Value, default(T));
}
result.ConvertToCardinal(tension);
return(result);
}
/// <summary>
/// Splits a hermite spline at a position.
/// Note that this may produce more than two output splines in order to eliminate discontinuities.
/// </summary>
/// <param name="splitPosition">The position at which to split the spline.</param>
/// <param name="output">The list that will receive the new splines created by the split (up to 4).</param>
public static void SplitInto <T> (
this HermiteSpline <T> spline,
float splitPosition,
List <HermiteSpline <T> > output
)
where T : struct
{
if ((splitPosition <= spline.Start) || (splitPosition >= spline.End))
{
output.Add(spline);
return;
}
int count = spline.Count;
int splitFirstPoint = spline.GetLowerIndexForPosition(splitPosition), splitSecondPoint = splitFirstPoint + 1;
HermiteSpline <T> temp;
if (splitFirstPoint > 0)
{
float position;
T value, velocity;
output.Add(temp = new HermiteSpline <T>());
for (int i = 0, end = splitFirstPoint; i <= end; i++)
{
spline.GetValuesAtIndex(i, out position, out value, out velocity);
temp.Add(position, value, velocity);
}
}
float firstPosition = spline.GetPositionAtIndex(splitFirstPoint), secondPosition = spline.GetPositionAtIndex(splitSecondPoint);
float splitLocalPosition = (splitPosition - firstPosition) / (secondPosition - firstPosition);
T a = spline.GetValueAtIndex(splitFirstPoint), d = spline.GetValueAtIndex(splitSecondPoint);
T u = spline.GetDataAtIndex(splitFirstPoint).Velocity, v = spline.GetDataAtIndex(splitSecondPoint).Velocity;
T b, c;
CurveUtil.HermiteToCubic(ref a, ref u, ref d, ref v, out b, out c);
var ab = Arithmetic.Lerp(a, b, splitLocalPosition);
var bc = Arithmetic.Lerp(b, c, splitLocalPosition);
var cd = Arithmetic.Lerp(c, d, splitLocalPosition);
var ab_bc = Arithmetic.Lerp(ab, bc, splitLocalPosition);
var bc_cd = Arithmetic.Lerp(bc, cd, splitLocalPosition);
var midpoint = Arithmetic.Lerp(ab_bc, bc_cd, splitLocalPosition);
T newA, newB, newC, newD, newU, newV;
newA = a;
newB = ab;
newC = ab_bc;
newD = midpoint;
CurveUtil.CubicToHermite(ref newA, ref newB, ref newC, ref newD, out newU, out newV);
output.Add(temp = new HermiteSpline <T>());
temp.Add(
firstPosition, newA, newU
);
temp.Add(
splitPosition, newD, newV
);
newA = midpoint;
newB = bc_cd;
newC = cd;
newD = d;
CurveUtil.CubicToHermite(ref newA, ref newB, ref newC, ref newD, out newU, out newV);
output.Add(temp = new HermiteSpline <T>());
temp.Add(
splitPosition, newA, newU
);
temp.Add(
secondPosition, newD, newV
);
if (splitSecondPoint < (count - 1))
{
float position;
T value, velocity;
output.Add(temp = new HermiteSpline <T>());
for (int i = splitSecondPoint, end = count - 1; i <= end; i++)
{
spline.GetValuesAtIndex(i, out position, out value, out velocity);
temp.Add(position, value, velocity);
}
}
}
