public new UnitVector orientedAgainst(Scientrace.Vector aVector)
{
if (aVector.dotProduct(this) > 0)
{
return(this.negative());
}
return(this);
}
//.tryToUnitVector()
public Vector orientedAlong(Scientrace.Vector aVector)
{
if (aVector.dotProduct(this) < 0)
{
return(this.negative());
}
return(this);
}
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)
}
public Vector reflectOnSurface(Scientrace.NonzeroVector norm)
{
Scientrace.Vector negdir = this.negative();
// Relative mirrorpoint: disregard the location of the line, just the orientations.
Scientrace.Vector rel_mirrorpoint = (norm.toVector() * negdir.dotProduct(norm));
//the distance from the surface normal to the direction vector (in the opposite direction) of the incoming line
Scientrace.Vector distance_to_normal = (negdir - rel_mirrorpoint);
//the direction of the reflected line
return(rel_mirrorpoint - distance_to_normal);
}