/// <summary>
/// This method is used by a <see cref="Hatch"/> object to calculate its contents. It generates a
/// set of parallel lines according to <see cref="LineDistance"/> and <see cref="LineAngle"/>
/// and clips them with the given shape. The lines are projected into the 3D world
/// by the given plane. <seealso cref="CompoundShape.Clip"/>
/// </summary>
/// <param name="shape">shape of the hatch object</param>
/// <param name="plane">local plane of the hatch object</param>
/// <returns></returns>
public override GeoObjectList GenerateContent(CompoundShape shape, Plane plane)
{
GeoObjectList res = new GeoObjectList();
if (shape == null)
{
return(res);
}
if (marginOffset != 0.0)
{
shape.Approximate(false, Settings.GlobalSettings.GetDoubleValue("Approximate.Precision", 0.01));
shape = shape.Shrink(marginOffset);
}
for (int i = 0; i < Math.Max(1, number); ++i)
{
double a = lineAngle.Radian + i * (double)offset;
ModOp2D m = ModOp2D.Rotate(new SweepAngle(-a));
BoundingRect ext = shape.GetExtent();
ext.Modify(m); // ext ist jetzt waagrecht, u.U. zu groß, was aber egal ist
m = ModOp2D.Rotate(new SweepAngle(a)); // die umgekehrte ModOp
int alt = 0;
// eine Linie soll durch die Mitte gehen
double c = (ext.Bottom + ext.Top) / 2.0;
double num = Math.Ceiling((c - ext.Bottom) / lineDistance);
ext.Bottom = c - num * lineDistance; // das untere Ende sowei nach unten verschoben, dass eine Linie durch die mitte geht
// das ist wichtig, weil sonst manche Schraffuren nicht zu picken sind, da keine Linie darin erscheint
// da eine Schraffur meist nur aus einem SimpleShape besteht, gibt es immer eine Linie durch die Mitte
for (double y = ext.Bottom; y < ext.Top; y += lineDistance)
{
GeoPoint2D startPoint = m * new GeoPoint2D(ext.Left, y);
GeoPoint2D endPoint = m * new GeoPoint2D(ext.Right, y);
Line2D l = new Line2D(startPoint, endPoint);
if (alternate && ((alt & 0x01) != 0))
{
l.Reverse();
}
double[] seg = shape.Clip(l, true);
for (int j = 0; j < seg.Length; j += 2)
{
IGeoObject go = l.Trim(seg[j], seg[j + 1]).MakeGeoObject(plane);
(go as ILineWidth).LineWidth = lineWidth;
(go as ILinePattern).LinePattern = linePattern;
(go as IColorDef).ColorDef = colorDef;
res.Add(go);
}
++alt;
}
}
return(res);
}