public double PointToSegDist(zhixian a, point c)
{
double b = a.k * c.X - c.Y + a.b;
double d = Math.Sqrt(a.k * a.k + 1);
return(Math.Abs(b / d));
}
//求两直线垂直k1和k2相乘=-1
public point jiaodian(zhixian a, zhixian b)
{
point p = new point();
p.X = (a.b - b.b) / (b.k - a.k);
p.Y = a.k * p.X + a.b;
return(p);
}
//算直线的k,b
public zhixian zx(point a, point b)
{
zhixian zhix = new zhixian();
zhix.k = (b.Y - a.Y) / (b.X - a.X);
zhix.b = a.Y - zhix.k * a.X;
return(zhix);
}
public bool zxjgd(zhixian a, point[] p, point b)
{
bool Bool = true;
for (int i = 0; i < p.Length - 2; i++)
{
if (!jiaodian(a, zx(p[i], p[i + 1]), b))
{
Bool = false;
}
}
return(Bool);//如果焦点不是本点输出true
}
public bool jiaodian(zhixian a, zhixian b, point c)
{
point p = new point();
p.X = (a.b - b.b) / (b.k - a.k);
p.Y = a.k * p.X + a.b;
if (p.X == c.X && p.Y == c.Y)
{
return(false);
}
else
{
return(true);
}
}
//角平分线
public zhixian zx(zhixian a, zhixian b, point c, point[] p, point d)
{
zhixian zhix = new zhixian();
zhix.k = (a.k * b.k - 1 + Math.Sqrt(((1 - a.k * b.k) * (1 - a.k * b.k)) + ((a.k + b.k) * (a.k + b.k)))) / (a.k + b.k);
zhix.b = c.Y - zhix.k * c.X;
if (zxjgd(zhix, p, d))
{
return(zhix);
}
else
{
zhix.k = (a.k * b.k - 1 - Math.Sqrt(((1 - a.k * b.k) * (1 - a.k * b.k)) + ((a.k + b.k) * (a.k + b.k)))) / (a.k + b.k);
zhix.b = c.Y - zhix.k * c.X;
return(zhix);
}
}
private void button2_Click(object sender, EventArgs e)
{
double[] mj = new double[bianshu];
double R2;
int min = 0;
yuan[] yan = new yuan[bianshu];
bool b = true;
point[] point1 = new point[points.Length + 3];
for (int q = 0; q < points.Length; q++)
{
point1[q].X = points[q].X;
point1[q].Y = points[q].Y;
}
point1[points.Length] = point1[0];//将第一个加到最后一个上面
point1[points.Length + 1] = point1[1];
point1[points.Length + 2] = point1[2];
for (int i = 0; i < points.Length; i++)
{
zhixian z1 = new zhixian();
z1 = wj.zx(wj.zx(point1[i], point1[i + 1]), wj.zx(point1[i + 1], point1[i + 2]), point1[i + 1], point1, point1[i + 1]);
zhixian z2 = new zhixian();
z2 = wj.zx(wj.zx(point1[i + 1], point1[i + 2]), wj.zx(point1[i + 2], point1[i + 3]), point1[i + 2], point1, point1[i + 2]);
yuan y = new yuan();
y = wj.neiqie(wj.jiaodian(z1, z2), point1[i], point1[i + 1]);
for (int n = 0; n < points.Length; n++)
{
R2 = wj.banjing(y.p, point1[n]);
if (y.R > R2)
{
b = false;
break;
}
else
{
b = true;
}
}
if (!b)
{
continue;
}
mj[i] = y.mianji;
yan[i] = y;
}
for (int j = 0; j < mj.Length; j++)
{
if (paidxu(chongpai(mj)) == mj[j])
{
min = j;
}
}
label1.Text = "外接圆的X坐标:" + yan[min].p.X + " " + "外接圆的Y坐标:" + yan[min].p.Y + " " + "外接圆的半径:" + yan[min].R;
Graphics gra = this.pictureBox1.CreateGraphics();
gra.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
Pen pen = new Pen(Color.Pink); //画笔颜色
gra.DrawEllipse(pen, (int)yan[min].p.X - (int)yan[min].R, (int)yan[min].p.Y - (int)yan[min].R, (int)yan[min].R * 2, (int)yan[min].R * 2); //画椭圆的方法，x坐标、y坐标、宽、高，如果是100，则半径为50
}
