/// <summary>
/// </summary>
/// <param name="controlPoints"></param>
/// <param name="knots">If null equidistant nodes will be generated.</param>
/// <param name="parameterCorrection"></param>
/// <param name="estimateScreenSpaceDistanceWithoutClip"></param>
/// <returns></returns>
public static List <Vertex> SampleBSplineCurve(IList <Point3D> controlPoints, IList <double> knots, bool parameterCorrection,
Func <Point3D, Point3D, double> estimateScreenSpaceDistanceWithoutClip)
{
var rawPointsList = new List <Vertex>();
var solver = new DeBoorSolverRecursive3D(controlPoints, knots);
if (controlPoints.Count <= 3)
{
return(rawPointsList);
}
var bernsteinPolygonLengthNoClip = BezierCurveC0.EstimateScreenSpacePolygonLength(
controlPoints,
estimateScreenSpaceDistanceWithoutClip,
controlPoints.Count - 1,
0
);
var generatedPointsBetween = (int)Math.Ceiling(bernsteinPolygonLengthNoClip);
for (var j = 0; j < generatedPointsBetween; ++j)
{
var t = (double)j / generatedPointsBetween;
var lerped = solver.Evaluate(t, parameterCorrection);
rawPointsList.Add(new Vertex()
{
Position = lerped, Color = Colors.White
});
}
return(rawPointsList);
}
protected override void CreateDirectionalSurfaceSampling(Func <Point3D, Point3D, double> estimateScreenDistanceWithoutClip,
Func <int, int, Tuple <int, int> > mapping, int subdivisions, List <Vertex> vertices, List <IndexedLine> lines)
{
var solvers = new DeBoorSolverRecursive3D[4];
for (var i = 0; i < 4; ++i)
{
var subcontrolPoints = new List <Point3D>();
for (var j = 0; j < 4; ++j)
{
var mapped = mapping(i, j);
subcontrolPoints.Add(ControlPoints[mapped.Item1 + mapped.Item2 * 4].Position);
}
solvers[i] = new DeBoorSolverRecursive3D(subcontrolPoints);
}
for (var i = 0; i < subdivisions; ++i)
{
var t = (double)i / (subdivisions - 1);
var subdivisionControlPoints = new List <Point3D>();
for (var j = 0; j < 4; ++j)
{
subdivisionControlPoints.Add(solvers[j].Evaluate(t, true));
}
var sampled = BezierCurveC2.SampleBSplineCurve(subdivisionControlPoints, null, true,
estimateScreenDistanceWithoutClip);
if (sampled.Count <= 1)
{
continue;
}
var sampledLines = Enumerable.Range(vertices.Count, sampled.Count - 1)
.Select(idx => new IndexedLine(idx, idx + 1))
.ToList();
vertices.AddRange(sampled);
lines.AddRange(sampledLines);
}
}
public Vector3D DerivativeU(double u, double v)
{
var recalculatedRowPoints = new List <Point3D>();
var dataRows = ControlPoints.Count / (3 + SegmentsU);
for (var column = 0; column < SegmentsU + 3; ++column)
{
var rowControlPoints = new List <Point3D>();
for (var row = 0; row < SegmentsV + 3; ++row)
{
var index = (3 + SegmentsU) * (row % dataRows) + column;
rowControlPoints.Add(ControlPoints[index]);
}
var solver = new DeBoorSolverRecursive3D(rowControlPoints);
var calculatedPoint = solver.Evaluate(v, true);
recalculatedRowPoints.Add(calculatedPoint);
}
var uSolver = new DeBoorSolverRecursive3D(recalculatedRowPoints);
return(uSolver.Derivative(u, true));
}