/// <summary>
/// kruznice urcena tremi body na obvodu
/// </summary>
/// <param name="pt1">prvni bod</param>
/// <param name="pt2">druhy bod</param>
/// <param name="pt3">treti bod</param>
public Circle2D(Point pt1, Point pt2, Point pt3)
{
Radius = 0;
Center = pt1;
Point[] p = new Point[2];
Vector[] v = new Vector[2];
p[0].X = (pt1.X + pt2.X) / 2;
p[0].Y = (pt1.Y + pt2.Y) / 2;
p[1].X = (pt2.X + pt3.X) / 2;
p[1].Y = (pt2.Y + pt3.Y) / 2;
v[0].X = pt2.Y - pt1.Y;
v[0].Y = -(pt2.X - pt1.X);
v[1].X = pt3.Y - pt2.Y;
v[1].Y = -(pt3.X - pt2.X);
TwoLine2D.CrossStatus st = TwoLine2D.CrossStatus.Infinite;
if (TwoLine2D.CrossAbs(p[0], st, v[0], st, p[1], st, v[1], st, out Center))
{
Radius = Funcs2D.Distance(pt1, Center);
}
}
private Object[] f_MakeCross()
{
Object[] ret = new Object[2];
List <Point> retPt = new List <Point>();
List <int> retInx = new List <int>();
Point[] bln = null, eln; // ofsetovane usecky
int b, m, e, len;
if (IsClosed)
{
b = mySrc.Length - 1;
m = 0;
len = mySrc.Length;
}
else
{
b = 0;
m = 1;
len = mySrc.Length - 1;
}
for (; m < len; m++)
{
e = m + 1;
if (e == mySrc.Length)
{
e = 0;
}
// test totoznych bodu
if (Funcs2D.IsEqual(mySrc[b].Pt, mySrc[m].Pt, Funcs2D.Epson))
{
b = m;
continue; // vynecham
}
// test tri body na jedne primce
if (Funcs2D.IsThreePointsOnLine(mySrc[b].Pt, mySrc[m].Pt, mySrc[e].Pt, Funcs2D.Epson))
{
b = m;
continue; // vynecham
}
//vypocitam offsety
if (bln == null)
{
bln = Funcs2D.LineOffset(mySrc[b].Pt, mySrc[m].Pt, mySrc[b].Offset);
}
eln = Funcs2D.LineOffset(mySrc[m].Pt, mySrc[e].Pt, mySrc[m].Offset);
if (!IsClosed && b == 0)
{
retPt.Add(bln[0]);
retInx.Add(0);
}
// prusecik
TwoLine2D.CrossAbs(bln[0], bln[1],
eln[0], eln[1],
TwoLine2D.CrossStatus.Infinite, out Point rpt);
retPt.Add(rpt);
retInx.Add(m);
if (!IsClosed && e == len)
{
retPt.Add(eln[1]);
retInx.Add(len);
}
b = m;
bln = eln;
}
if (len == 1)
{
bln = Funcs2D.LineOffset(mySrc[b].Pt, mySrc[m].Pt, mySrc[b].Offset);
retPt.Add(bln[0]);
retInx.Add(0);
retPt.Add(bln[1]);
retInx.Add(1);
}
ret[0] = retPt;
ret[1] = retInx;
return(ret);
}