//always return one valid point.
public bool GetIntersection(sLine ln, double tolerance, out sGeometryBase intGeo)
{
double t0;
double t1;
double dis = this.GetClosestDistanceBetween(ln, out t0, out t1);
sLine rl = this.Reversed();
double rt0;
double rt1;
double rdis = rl.GetClosestDistanceBetween(ln, out rt0, out rt1);
if (dis < tolerance && rdis < tolerance)
{
if (this.PointAt(t0).DistanceTo(rl.PointAt(rt0)) > tolerance)
{
//line
intGeo = new sLine(this.PointAt(t0), rl.PointAt(rt0));
return(true);
}
else
{
//point
intGeo = this.PointAt(t0);
return(true);
}
}
else
{
//none
intGeo = null;
return(false);
}
}
public void ComputeFaceNormal(sMesh m)
{
sLine l0 = new sLine(m.vertices[this.A].location, m.vertices[this.B].location);
sLine l1 = new sLine(m.vertices[this.A].location, m.vertices[this.C].location);
this.normal = sXYZ.CrossProduct(l0.direction, l1.direction);
}
public sLine DuplicatesLine()
{
sLine nl = new sLine(this.startPoint.DuplicatesXYZ(), this.endPoint.DuplicatesXYZ());
nl.objectGUID = this.objectGUID;
return(nl);
}
public double ParameterOn(sLine ln)
{
double t;
ln.GetClosestDistanceTo(this, out t);
return(t);
}
public double GetClosestDistanceTo(sXYZ p, out double t)
{
sXYZ minuteVec = new sXYZ(0.00001, 0, 0);
sLine ln = new sLine(p, p + minuteVec);
double t0;
double t1;
double dis = this.GetClosestDistanceBetween(ln, out t0, out t1);
t = t0;
return(dis);
}
public bool Intersect(sCurve c, double tol, out List <sXYZ> intPts, out List <sCurve> intCrvs)
{
bool doesIntersect = false;
List <sXYZ> ips = new List <sXYZ>();
List <sCurve> ics = new List <sCurve>();
if (this.curveType == eCurveType.LINE && c.curveType == eCurveType.LINE)
{
sLine l1 = this as sLine;
sLine l2 = c as sLine;
sGeometryBase igeo;
doesIntersect = l1.GetIntersection(l2, tol, out igeo);
if (igeo is sLine)
{
ics.Add(igeo as sCurve);
}
else if (igeo is sXYZ)
{
ips.Add(igeo as sXYZ);
}
}
else if (this.curveType == eCurveType.LINE && c.curveType == eCurveType.POLYLINE)
{
sPolyLine pl = c as sPolyLine;
pl.GetIntersection(this, tol, out ips, out ics);
}
else if (this.curveType == eCurveType.POLYLINE && c.curveType == eCurveType.LINE)
{
sPolyLine pl = this as sPolyLine;
pl.GetIntersection(c, tol, out ips, out ics);
}
else if (this.curveType == eCurveType.POLYLINE && c.curveType == eCurveType.POLYLINE)
{
sPolyLine pl = this as sPolyLine;
pl.GetIntersection(c, tol, out ips, out ics);
}
intCrvs = ics;
intPts = ips;
return(doesIntersect);
}
public sCurve DuplicatesCurve()
{
if (this.curveType == eCurveType.LINE)
{
sLine sc = this as sLine;
return(sc.DuplicatesLine());
}
else if (this.curveType == eCurveType.POLYLINE)
{
sPolyLine thispl = this as sPolyLine;
return(thispl.DuplicatesPolyline());
}
else if (this.curveType == eCurveType.NURBSCURVE)
{
sNurbsCurve nc = this as sNurbsCurve;
return(nc.DuplicatesNurbsCurve());
}
else
{
return(null);
}
}
public sLine Reversed()
{
sLine rl = new sLine(this.endPoint, this.startPoint);
return(rl);
}
public double GetClosestDistanceBetween(sLine ln, out double t0, out double t1)
{
sXYZ u = this.endPoint - this.startPoint;
sXYZ v = ln.endPoint - ln.startPoint;
sXYZ w = this.startPoint - ln.startPoint;
double a = u * u; // sXYZ.Dot(u, u);
double b = u * v; // sXYZ.Dot(u, v);
double c = v * v; // sXYZ.Dot(v, v);
double d = u * w; // sXYZ.Dot(u, w);
double e = v * w; // sXYZ.Dot(v, w);
double D = (a * c) - (b * b);
double sc = 0.0;
double sN = 0.0;
double sD = D;
double tc = 0.0;
double tN = 0.0;
double tD = D;
if (D < 0.00001)
{
//parallel
sN = 0.0;
sD = 1.0;
tN = e;
tD = c;
}
else
{
sN = (b * e - c * d);
tN = (a * e - b * d);
if (sN < 0.0)
{
sN = 0.0;
tN = e;
tD = c;
}
else if (sN > sD)
{
sN = sD;
tN = e + b;
tD = c;
}
}
if (tN < 0.0)
{
tN = 0.0;
if (-d < 0.0)
{
sN = 0.0;
}
else if (-d > a)
{
sN = sD;
}
else
{
sN = -d;
sD = a;
}
}
else if (tN > tD)
{
tN = tD;
if ((-d + b) < 0.0)
{
sN = 0;
}
else if ((-d + b) > a)
{
sN = sD;
}
else
{
sN = (-d + b);
sD = a;
}
}
if (Math.Abs(sN) < 0.0001)
{
sc = 0.0;
}
else
{
sc = (sN / sD);
}
if (Math.Abs(tN) < 0.0001)
{
tc = 0.0;
}
else
{
tc = (tN / tD);
}
sXYZ cp = w + (sc * u) - (tc * v);
t0 = sc;
t1 = tc;
return(cp.GetLength());
}
