public static MinimumRadiusResult FindMinimumRadius(this ICurve curve)
{
var bound = curve.Domain();
int numOfRadius = 0;
object radiusObject = null;
object locationObject = null;
object tObject = null;
var hasRadius = curve.FindMinimumRadius(bound
, ref numOfRadius
, ref radiusObject
, ref locationObject
, ref tObject);
if (hasRadius && numOfRadius > 0)
{
return(new MinimumRadiusResult
(t: ((double[])tObject)[0]
, radius: ((double[])radiusObject)[0]
, location: ((MathPoint)((object[])locationObject)[0]).ToVector3()));
}
else
{
return(null);
}
}
public static PointParamWithRayProjection ClosestPointToRay(this ICurve curve, PointDirection3 ray, double tol = 1e-9)
{
var bound = curve.Domain();
int numOfRadius = 0;
double[] radius = null;
MathPoint location = null;
var radiusResult = curve.FindMinimumRadius();
var domain = new RangeDouble(curve.Domain());
var tessTol = radiusResult.Radius / 10;
var closestPointOnEdge = Vector3.Zero;
for (var i = 0; i < 1; i++)
{
var tessPoints = Sequences
.LinSpace(domain.Min, domain.Max, 100)
.Select(curve.PointParamAt).ToList();
var edges = tessPoints.Buffer(2, 1).Where(buf => buf.Count == 2)
.ToList();
var closestEdge
= edges
.Select(edge => new { edge, connection = MakeEdge(edge).ShortestEdgeJoining(ray, tol) })
.MinBy(o => o.connection.LengthSquared)[0];
var a = closestEdge.edge[0].T;
var b = closestEdge.edge[1].T;
domain = new RangeDouble(a, b);
tessTol = tessTol / 10;
}
Func <Vector3, Vector3> projectOnRay = p => (p - ray.Point).ProjectOn(ray.Direction) + ray.Point;
var solver = new BrentSearch(t =>
{
var p = curve.PointAt(t);
var proj = projectOnRay(p);
return((p - proj).LengthSquared());
}, domain.Min, domain.Max);
solver.Minimize();
var minT = solver.Solution;
var pointParam = curve.PointParamAt(minT);
return(new PointParamWithRayProjection(pointParam, projectOnRay(pointParam.Point)));
}