/* end of interface IBorder3D implementation */
public IntersectionPoint[] intersectionPoints(Trace trace)
{
VectorTransform trf = this.getTransform();
// the points (any V) on the center line of this cylinder is described by "V = s + x l" for any x.
Vector s = trf.transform(trace.traceline.startingpoint-this.loc);
Vector l = trf.transform(trace.traceline.direction);
double r = 1; // not (this.radius;) as the transformation rendered it 1.
double ABCa = Math.Pow(l.x,2) + Math.Pow(l.y,2);
double ABCb = 2*((s.x*l.x)+(s.y*l.y));
double ABCc = Math.Pow(s.x,2) + Math.Pow(s.y,2) - r*r;
QuadraticEquation qe = new QuadraticEquation(ABCa, ABCb, ABCc);
Scientrace.IntersectionPoint[] ips = new Scientrace.IntersectionPoint[2]{null, null};
if (!qe.hasAnswers) { return ips; }
for (int iAns = 1; iAns <= qe.answerCount; iAns++) {
double x = qe.getAnswer(iAns);
if (Double.IsNaN(x))
throw new ArgumentNullException("Answer {"+iAns+"} is NaN.\n\n qe details:"+qe.ToString());
Vector tLoc = s + (l * x);
Vector tNormal = new Vector(tLoc.x, tLoc.y, 0);
Location oLoc = (trf.transformback(tLoc)+this.loc).toLocation();
UnitVector oNormal = null;
try {
oNormal = trf.transformback(tNormal).tryToUnitVector();
} catch { new ZeroNonzeroVectorException("oNormal is a zerovector which cannot be normalised for o3d ["+this.tag+"] and trace "+trace.ToCompactString()); }
ips[iAns-1] = Scientrace.IntersectionPoint.locAtSurfaceNormal(oLoc, oNormal);
}
/* switch (qe.answerCount) {
case 2:
Scientrace.Location minLoc = ((l*qe.minVal) + o).toLocation();
Scientrace.NonzeroVector minNorm = (minLoc - c).tryToNonzeroVector();
ips[0] = Scientrace.IntersectionPoint.locAtSurfaceNormal(minLoc, minNorm);
Scientrace.Location plusLoc = ((l*qe.plusVal) + o).toLocation();
Scientrace.NonzeroVector plusNorm = (plusLoc - c).tryToNonzeroVector();
ips[1] = Scientrace.IntersectionPoint.locAtSurfaceNormal(plusLoc, plusNorm);
return new Intersection(aTrace, ips, this);
//goto case 1; //continue to case 1
case 1:
Scientrace.Location loc = ((l*qe.plusVal) + o).toLocation();
Scientrace.NonzeroVector norm = (loc - c).tryToNonzeroVector();
ips[0] = Scientrace.IntersectionPoint.locAtSurfaceNormal(loc, norm);
ips[1] = null;
return new Intersection(aTrace, ips, this);
default:
throw new IndexOutOfRangeException("eq.answerCount is not allowed to be "+qe.answerCount.ToString()+"in Shpere.intersects(..)");
} //end switch(qe.answerCount)
*/
return ips;
}
public override Intersection intersects(Scientrace.Trace aTrace)
{
Scientrace.Vector c = this.loc;
Scientrace.Vector o = aTrace.traceline.startingpoint;
Scientrace.Vector l = aTrace.traceline.direction;
Scientrace.Vector y = o-c;
double r = this.radius;
double ABCa = l.dotProduct(l);
double ABCb = l.dotProduct(y)*2;
double ABCc = y.dotProduct(y)-(r*r);
QuadraticEquation qe = new QuadraticEquation(ABCa,ABCb,ABCc);
// if the trace doesn't hit the sphere, return a "false Intersection"
if (!qe.hasAnswers) { return new Intersection(false, this); }
Scientrace.IntersectionPoint[] ips = new Scientrace.IntersectionPoint[2];
switch (qe.answerCount) {
case 2:
Scientrace.Location minLoc = ((l*qe.minVal) + o).toLocation();
Scientrace.NonzeroVector minNorm = (minLoc - c).tryToNonzeroVector();
ips[0] = Scientrace.IntersectionPoint.locAtSurfaceNormal(minLoc, minNorm);
Scientrace.Location plusLoc = ((l*qe.plusVal) + o).toLocation();
Scientrace.NonzeroVector plusNorm = (plusLoc - c).tryToNonzeroVector();
ips[1] = Scientrace.IntersectionPoint.locAtSurfaceNormal(plusLoc, plusNorm);
return new Intersection(aTrace, ips, this);
//goto case 1; //continue to case 1
case 1:
Scientrace.Location loc = ((l*qe.plusVal) + o).toLocation();
Scientrace.NonzeroVector norm = (loc - c).tryToNonzeroVector();
ips[0] = Scientrace.IntersectionPoint.locAtSurfaceNormal(loc, norm);
ips[1] = null;
return new Intersection(aTrace, ips, this);
default:
throw new IndexOutOfRangeException("eq.answerCount is not allowed to be "+qe.answerCount.ToString()+"in Shpere.intersects(..)");
} //end switch(qe.answerCount)
}
