public static (DoubleVector2, DoubleVector2) FindCollinearBounds(DoubleVector2 a, DoubleVector2 b, DoubleVector2 c)
{
var ab = a.To(b).SquaredNorm2D();
var ac = a.To(c).SquaredNorm2D();
var bc = b.To(c).SquaredNorm2D();
if (ab > ac)
{
return(ab > bc ? (a, b) : (b, c));
}
else
{
return(ac > bc ? (a, c) : (b, c));
}
}
public static bool TryFindNonoverlappingLineLineIntersectionT(DoubleVector2 a1, DoubleVector2 a2, DoubleVector2 b1, DoubleVector2 b2, out double tForA)
{
// via http://stackoverflow.com/questions/563198/how-do-you-detect-where-two-line-segments-intersect
var p = a1;
var r = a1.To(a2);
var q = b1;
var s = b1.To(b2);
var rxs = Cross(r, s);
if (rxs == 0) // iffy?
{
goto fail;
}
var qmp = q - p;
var t = Cross(qmp, s) / (double)rxs;
tForA = t;
return(true);
fail:
tForA = Double.NaN;
return(false);
}
private void InsertInternal(ref IntLineSegment2 s, double insertionThetaLower, double insertionThetaUpper, bool supportOverlappingLines)
{
if (insertionThetaLower == insertionThetaUpper)
{
return;
}
// Console.WriteLine($"InsertInternal: {s}, {thetaLower} {thetaUpper}");
// cull if wall faces away from origin
var sperp = new DoubleVector2(s.Y2 - s.Y1, -(s.X2 - s.X1));
var os1 = _origin.To(s.First.ToDoubleVector2());
if (sperp.Dot(os1) < 0)
{
//return;
}
var rangeId = rangeIdCounter++;
InsertInternalInternal(s, rangeId, insertionThetaLower, insertionThetaUpper, supportOverlappingLines, false);
}