public static double[] AnglesCrossLine(Point centre, double r, Point pt1, Point pt2)
{
Point t = Funcs2D.PointToLine(pt1, pt2, centre);
if (Funcs2D.IsEqual(t, centre))
{
double an = Funcs2D.LineAngle(pt1, pt2);
return(new double[] { Funcs2D.PureRadianAngle(an + Math.PI), an });
}
double z = Funcs2D.Distance(centre, t);
double a = Funcs2D.LineAngle(centre, t);
if (z.IsGreater(r))
{
return(null); // mimo
}
if (z.IsEqual(r)) // tecna
{
return(new double[] { a });
}
//secna
double aa = Math.Acos(z / r); // uhel pulky tetivy
return(new double[] { Funcs2D.PureRadianAngle(a + aa), Funcs2D.PureRadianAngle(a - aa) });
}
public static ParallelResult ParallelCheck(
Point pta, Vector da, //bod a vektor prvni primky
Point ptb, Vector db, //bod a vektor druhe primky
out Point retRel, // vraci relativni souradnice ( x = begin, y = end) na prvni primce
out bool direct) // smer vektoru primek, true stejny smer, false opacny smer
{
retRel = new Point();
direct = false;
var rr = Funcs2D.IsParallel(da, db);
if (rr == 0)
{
return(ParallelResult.Nothing);
}
direct = rr > 0;
retRel.X = Funcs2D.PointToLine(pta, da, ptb);
retRel.Y = Funcs2D.PointToLine(pta, da, ptb.Plus(db));
if (Funcs2D.IsThreePointsOnLine(pta, pta.Plus(da), ptb))
{
return(ParallelResult.ParallelOn);
}
else
{
return(ParallelResult.ParallelOut);
}
}