//函数——判断P是否在外接圆的内部
public bool JudgeInTriangle(point P, triangle T)
{
bool Inside = true;
point A = new point();
point B = new point();
point C = new point();
A = T.Tp[0];
B = T.Tp[1];
C = T.Tp[2];
double x1, y1, x2, y2, x3, y3;
x1 = A.x;
y1 = A.y;
x2 = B.x;
y2 = B.y;
x3 = C.x;
y3 = C.y;
double x0, y0, r, d;
x0 = ((B.y - A.y) * (C.y * C.y - A.y * A.y + C.x * C.x - A.x * A.x) - (C.y - A.y) * (B.y * B.y - A.y * A.y + B.x * B.x - A.x * A.x)) /
(2 * (C.x - A.x) * (B.y - A.y) - 2 * (B.x - A.x) * (C.y - A.y));
y0 = ((B.x - A.x) * (C.x * C.x - A.x * A.x + C.y * C.y - A.y * A.y) - (C.x - A.x) * (B.x * B.x - A.x * A.x + B.y * B.y - A.y * A.y)) /
(2 * (C.y - A.y) * (B.x - A.x) - 2 * (B.y - A.y) * (C.x - A.x));
r = Math.Round(Math.Sqrt((x0 - A.x) * (x0 - A.x) + (y0 - A.y) * (y0 - A.y)), 4);
d = Math.Round(Math.Sqrt((x0 - P.x) * (x0 - P.x) + (y0 - P.y) * (y0 - P.y)), 4);
if (d <= r)
{
Inside = true;
}
else
{
Inside = false;
}
return(Inside);
}
//构建初始三角网
public void BuildInitialTin()
{
int a = CP.Count;
for (int i = 0; i < PO.Count - 1; i++)
{
side l1 = new side();
side l2 = new side();
side l3 = new side();
l1.Sp = new List <point>();
l2.Sp = new List <point>();
l3.Sp = new List <point>();
triangle t1 = new triangle();
t1.Ts = new List <side>();
t1.Tp = new List <point>();
t1.Tp.Add(PO[i]);
t1.Tp.Add(PO[i + 1]);
t1.Tp.Add(CP[0]);
l1.Sp.Add(PO[i]);
l1.Sp.Add(PO[i + 1]);
l2.Sp.Add(PO[i + 1]);
l2.Sp.Add(CP[0]);
l3.Sp.Add(PO[i]);
l3.Sp.Add(CP[0]);
t1.Ts.Add(l1);
t1.Ts.Add(l2);
t1.Ts.Add(l3);
T1.Add(t1);
}
}
//判断点是否位于三角形内
public bool PinT(point p, triangle t)
{
bool In = true;
double s1, s2, s3, s4;
s1 = Area(t.Tp[0], t.Tp[1], t.Tp[2]);
s2 = Area(t.Tp[0], t.Tp[1], p);
s3 = Area(t.Tp[1], t.Tp[2], p);
s4 = Area(t.Tp[0], t.Tp[2], p);
if (Math.Round(s1, 4) == Math.Round((s2 + s3 + s4), 4))
{
In = true;
}
else
{
In = false;
}
return(In);
}
//生成平面三角网
public void BuildPlaneTIN()
{
//循环点
for (int i = 1; i < CP.Count; i++)
{
int T1count = T1.Count;
List <triangle> T3 = new List <triangle>();
//找出所有外接圆包含P的三角形
for (int j = 0; j < T1count; j++)
{
if (JudgeInTriangle(CP[i], T1[j]))
{
T3.Add(T1[j]);
}
}
//定位
List <triangle> FT = new List <triangle>();
for (int k = 0; k < T3.Count; k++)
{
if (PinT(CP[i], T3[k]))
{
FT.Add(T3[k]);
T3.Remove(T3[k]);
break;
}
}
if (FT.Count > 0)
{
if (T3.Count > 0)
{
int[] Tnote = new int[T3.Count];
//设立标志数组
for (int t = 0; t < T3.Count; t++)
{
Tnote[t] = 0;
}
int v = 0;
int num = 0;
bool F = true;
while (F)
{
if (Tnote[v] == 0)
{
for (int vv = 0; vv < FT.Count; vv++)
{
if (JudgeSame(T3[v], FT[vv]))
{
FT.Add(T3[v]);
Tnote[v] = 1;
v = -1;
break;
}
else
{
num = vv;
}
}
if (v == (T3.Count - 1) && num == (FT.Count - 1))
{
F = false;
}
}
v += 1;
if (v == T3.Count)
{
F = false;
}
}
}
//将三角形加入到T2中
T2.AddRange(FT);
//移除T1中三角形;
for (int y = 0; y < T2.Count; y++)
{
T1.Remove(T2[y]);
}
//寻找公共边
for (int t2 = 0; t2 < T2.Count - 1; t2++) //第一个三角形
{
int ii = t2 + 1; //其余三角形
while (ii <= T2.Count - 1)
{
if (JudgeSame(T2[t2], T2[ii]))
{
//移除公共边
T2[t2].Ts.Remove(SameSide);
T2[ii].Ts.Remove(SameSide1);
}
ii += 1;
}
}
//将剩下的边添加到S中
S.Clear();
for (int a1 = 0; a1 < T2.Count; a1++)
{
for (int a2 = 0; a2 < T2[a1].Ts.Count; a2++)
{
S.Add(T2[a1].Ts[a2]);
}
}
//清空T2
T2.Clear();
//生成新的三角形并添加到T1中
for (int a3 = 0; a3 < S.Count; a3++)
{
side s0 = new side();
side s1 = new side();
side s2 = new side();
triangle t = new triangle();
//实例化
s0.Sp = new List <point>();
s1.Sp = new List <point>();
s2.Sp = new List <point>();
t.Tp = new List <point>();
t.Ts = new List <side>();
//三个顶点
t.Tp.Add(S[a3].Sp[0]);
t.Tp.Add(S[a3].Sp[1]);
t.Tp.Add(CP[i]);
//三条边
s0 = S[a3];
s1.Sp.Add(S[a3].Sp[1]);
s1.Sp.Add(CP[i]);
s2.Sp.Add(S[a3].Sp[0]);
s2.Sp.Add(CP[i]);
t.Ts.Add(s0);
t.Ts.Add(s1);
t.Ts.Add(s2);
T1.Add(t);
}
}
}
}
