// vypocita rovnobeznou primku
public static Point[] LineOffset(Point pt1, Point pt2, double offset)
{
Vector vv = pt2.Minus(pt1), // vektor
nv = Funcs2D.VectorNormal(vv); // kolmy vektor
Point[] ret = new Point[2];
if (Funcs2D.IsNull(vv))
{
ret[0] = pt1;
ret[1] = pt2;
return(ret);
}
;
double len = vv.Length, // delka primky
kn = offset / len; // delkovy koeficient offsetu
// prvni bod
ret[0].X = pt1.X + (kn * nv.X);
ret[0].Y = pt1.Y + (kn * nv.Y);
// druhy bod
ret[1].X = ret[0].X + vv.X;
ret[1].Y = ret[0].Y + vv.Y;
return(ret);
}
/// <summary>
/// vytvori oblouk zadany pocatecnim bodem, vektorem ve kterm je koncovy bod a zdvihem v poloine usecky
/// </summary>
/// <param name="pt1">pocatecni bod oblouku</param>
/// <param name="v">vektor udavajici koncovy bod oblouky</param>
/// <param name="elevation">zdvih oblouku v polovine usecky [pt1,v]</param>
/// <returns></returns>
public static Arc2D Arc2DElevation(Point pt1, Vector v, double elevation)
{
Point pt2, pt3 = pt1.Plus(v);
pt2 = Funcs2D.PointOnLineLen(Funcs2D.PointOnLine(pt1, v, 0.5), Funcs2D.VectorNormal(v), elevation);
return(new Arc2D(pt1, pt2, pt3));
}
//vypocita kolmy prumet bodu na usecce , vysledek je relativni souradnice usecky
public static double PointToLine(Point pt1, Vector v, Point pk)
{
Vector vn = Funcs2D.VectorNormal(v);
TwoLine2D.CrossRel(pt1, v, pk, vn, out Point ret);
return(ret.X);
}
public static IPolygonReader[] PolygonsInterconnect(IPolygonReader[] polygons, Point pt, Vector v)
{
IPolygonReader[] ret = null;
List <Tuple <double, int, int> > cr = new List <Tuple <double, int, int> >();
bool[] bcr = new bool[polygons.Length];
Point ptt = new Point();
Vector norm = Funcs2D.VectorNormal(v);
for (int i = 0; i < polygons.Length; i++)
{
for (int j = 0; j < polygons[i].Length; j++)
{
polygons[i].GetRow(j, out double x, out double y);
ptt.X = x; ptt.Y = y;
if (TwoLine2D.CrossRel(pt, v, ptt, norm, out Point pr))
{
if (Funcs2D.IsEqual(pr.Y, 0.0, Funcs2D.Epson))
{
cr.Add(new Tuple <double, int, int>(pr.X, i, j));
bcr[i] = true;
}
}
}
}
if (cr.Count < 2)
{
return(null);
}
int k = 1;
foreach (var b in bcr)
{
if (!b)
{
k++;
}
}
ret = new IPolygonReader[k];
k = 0;
for (int i = 0; i < bcr.Length; i++)
{
if (!bcr[i])
{
ret[k++] = polygons[i];
}
}
// trideni
cr.Sort((a, b) => a.Item1.CompareTo(b.Item1));
List <Point> rpt = new List <Point>();
f_InterconnectJoin(0, cr, polygons, rpt);
ret[k] = new BoxListPoint(Funcs2D.PolygonPure(new BoxListPoint(rpt), true));
return(ret);
}
public static Point LineRelPtOffset(Point pt1, Vector vv, double rel, double offset)
{
Point ret = new Point();
Vector nv = Funcs2D.VectorNormal(vv); // kolmy vektor
if (Funcs2D.IsNull(vv))
{
return(ret);
}
double len = vv.Length, // delka primky
kn = offset / len; // delkovy koeficient offsetu
Point pt = PointOnLine(pt1, vv, rel);
ret.X = pt.X + (kn * nv.X);
ret.Y = pt.Y + (kn * nv.Y);
return(ret);
}