private bool showLine()
{
ArrayList usableCurves = new ArrayList(); // lokales Array, das die gültigen Kurven sammelt
double mindist = double.MaxValue;
for (int i = 0; i < tangCurves.Length; ++i)
{
Plane pl;
double lineAngle;
if (Curves.GetCommonPlane(objectPoint, tangCurves[i], out pl))
{
ICurve2D l2D = tangCurves[i].GetProjectedCurve(pl);
if (l2D is Path2D)
{
(l2D as Path2D).Flatten();
}
lineAngle = pl.Project(lineDir).Angle; // 2D-Winkel aus der Richtung erzeugen
GeoPoint2D[] tangentPoints = l2D.TangentPointsToAngle(lineAngle, pl.Project(objectPoint));
if (tangentPoints.Length > 0)
{ // eine gültige Kurve ist gefunden
usableCurves.Add(tangCurves[i]);
for (int j = 0; j < tangentPoints.Length; ++j)
{
double dist = Geometry.Dist(tangentPoints[j], pl.Project(objectPoint));
if (dist < mindist)
{
mindist = dist;
selected = usableCurves.Count - 1; // merken, welche Kurve die aktuell benutzte ist
startPoint2D = tangentPoints[j];
}
}
}
}
if (mindist < double.MaxValue)
{
if (!linePositionMiddle)
{
startPoint = pl.ToGlobal(startPoint2D);
endPoint = startPoint + lineLength * lineDir;
}
else
{
startPoint = pl.ToGlobal(startPoint2D) - (lineLength / 2.0) * lineDir;
endPoint = pl.ToGlobal(startPoint2D) + (lineLength / 2.0) * lineDir;
}
line.SetTwoPoints(startPoint, endPoint);
tangCurves = (ICurve[])usableCurves.ToArray(typeof(ICurve)); // tangCurves wird mit den gültigen überschrieben und unten zur Anzeige zurückgegeben an den Sender
base.BasePoint = pl.ToGlobal(startPoint2D);
// base.BasePoint = line.StartPoint;
return(true);
}
}
// hier Prototyp-Darstellung:
if (!linePositionMiddle)
{
startPoint = base.BasePoint;
endPoint = startPoint + lineLength * lineDir;
}
else
{
startPoint = base.BasePoint - (lineLength / 2.0) * lineDir;
endPoint = base.BasePoint + (lineLength / 2.0) * lineDir;
}
// startPoint = base.BasePoint;
// endPoint = startPoint+lineLength*lineDir;
line.SetTwoPoints(startPoint, endPoint);
return(false);
}
