public override ICurve2D GetProjectedCurve(ICurve curve, double precision)
{
#if DEBUG
if (id == 135 || id == 414)
{
}
#endif
if (curve is Line line)
{
// this must be a line parallel to the axis, otherwise there are no lines on the cylinder
// if it is an extremely small line not parallel to the axis, the result will also be a line, which
// in reverse projection will give a very short ellipse
return(new Line2D(PositionOf(line.StartPoint), PositionOf(line.EndPoint)));
}
else if (curve is Ellipse elli)
{
// the ellipse must be above the projection center of the 2d system
// otherwise it is probably a hyperbola
GeoPoint p1 = Geometry.DropPL(elli.Center + elli.MajorAxis, location, zAxis);
GeoPoint p2 = Geometry.DropPL(elli.Center - elli.MajorAxis, location, zAxis);
double pos1 = Geometry.LinePar(location - zAxis, zAxis, p1);
double pos2 = Geometry.LinePar(location - zAxis, zAxis, p2);
if (pos1 < 0 || pos2 < 0)
{
return(base.GetProjectedCurve(curve, precision));
}
double d = Geometry.DistPL(elli.Center, location, zAxis);
double prec = (elli.MajorRadius + elli.MinorRadius) * 1e-6;
// FromFivePoints for this case
GeoPoint2D[] fp2d = new GeoPoint2D[5];
double n = 5.0;
if (elli.IsArc)
{
n = 4;
}
for (int i = 0; i < 5; i++)
{
fp2d[i] = PositionOf(elli.PointAt(i / n));
}
Ellipse2D elli2d = Ellipse2D.FromFivePoints(fp2d, !elli.IsArc); // returns both full ellipse and ellipse arc
if (elli2d != null)
{
if (elli.IsArc)
{
double spar = elli2d.PositionOf(PositionOf(elli.StartPoint));
double epar = elli2d.PositionOf(PositionOf(elli.EndPoint));
EllipseArc2D elliarc2d = elli2d.Trim(spar, epar) as EllipseArc2D;
// there must be a more sophisticated way to calculate the orientation and which part to use, but the following works:
double pm = elliarc2d.PositionOf(PositionOf(elli.PointAt(0.5)));
if (pm < 0 || pm > 1)
{
elliarc2d = elliarc2d.GetComplement();
}
pm = elliarc2d.PositionOf(PositionOf(elli.PointAt(0.1)));
if (pm > 0.5)
{
elliarc2d.Reverse();
}
return(elliarc2d);
}
else
{ // get the correct orientation
double pos = elli2d.PositionOf(PositionOf(elli.PointAt(0.1)));
if (pos > 0.5)
{
elli2d.Reverse();
}
return(elli2d);
}
}
}
return(base.GetProjectedCurve(curve, precision));
}
public override ICurve2D GetProjectedCurve(ICurve curve, double precision)
{
ICurve2D dbg = base.GetProjectedCurve(curve, precision);
if (curve is Ellipse elli)
{ // a circle on the surface is projected to an ellipse in the uv plane
GeoPoint2D[] positions = new GeoPoint2D[5];
for (int i = 0; i < 5; i++)
{
positions[i] = PositionOf(elli.PointAtParam(i * Math.PI * 2.0 / 6.0));
}
Ellipse2D elli2d = Ellipse2D.FromFivePoints(positions, true);
double prec = precision;
if (prec == 0)
{
prec = Precision.eps;
}
if (elli2d == null)
{
BoundingRect ext = new BoundingRect(positions);
GaussNewtonMinimizer.Ellipse2DFit(new ToIArray <GeoPoint2D>(positions), ext.GetCenter(), ext.Size / 2.0, ext.Size / 3.0, 0.0, prec, out elli2d);
}
else
{
GaussNewtonMinimizer.Ellipse2DFit(new ToIArray <GeoPoint2D>(positions), elli2d.center, elli2d.majrad, elli2d.minrad, elli2d.majorAxis.Angle, prec, out elli2d);
}
//GeoPoint2D center = PositionOf(elli.Center);
//GeoPoint2D maj = PositionOf(elli.Center + elli.MajorAxis);
//GeoPoint2D min = PositionOf(elli.Center + elli.MinorAxis);
//Geometry.PrincipalAxis(maj - center, min - center, out GeoVector2D majorAxis, out GeoVector2D minorAxis);
//Ellipse2D elli2d = new Ellipse2D(center, maj - center, min - center);
if (elli2d == null)
{
return(base.GetProjectedCurve(curve, precision));
}
if (elli.IsArc)
{
double sp = elli2d.PositionOf(PositionOf(elli.StartPoint));
double ep = elli2d.PositionOf(PositionOf(elli.EndPoint));
EllipseArc2D elliarc2d = elli2d.Trim(sp, ep) as EllipseArc2D;
// there must be a more sophisticated way to calculate the orientation and which part to use, but the following works:
double pm = elliarc2d.PositionOf(PositionOf(elli.PointAt(0.5)));
if (pm < 0 || pm > 1)
{
elliarc2d = elliarc2d.GetComplement();
}
pm = elliarc2d.PositionOf(PositionOf(elli.PointAt(0.1)));
if (pm > 0.5)
{
elliarc2d.Reverse();
}
return(elliarc2d);
}
else
{ // get the correct orientation
double pos = elli2d.PositionOf(PositionOf(elli.PointAt(0.1)));
if (pos > 0.5)
{
elli2d.Reverse();
}
return(elli2d);
}
}
return(base.GetProjectedCurve(curve, precision));
}
