int judge_left(given_point p1, given_point p2, given_point p3) //判断点是否在线的左边
{
if (p1.X * p2.Y - p2.X * p1.Y + p3.X * (p1.Y - p2.Y) + p3.Y * (p2.X - p1.X) > 0)
{
return(1);
}
return(-1);
}
int judge(grid_point a, given_point b, given_point c) //判断点a是否在b—c线的左边
{
double m = (c.X - b.X) / (c.Y - b.Y) * (a.y - b.Y) + b.X;
if (m > a.x)
{
return(1);
}
return(0);
}
private void openfile_Click(object sender, EventArgs e) //打开读取数据文件
{
try // 进行错误处理
{
if (datatable.Rows.Count != 1)
{
datatable.Rows.Clear(); g_point.Clear(); convex_hull.Clear(); report.Clear();
} //如果当前数据表格中有数据，在
//这次导入数据前清空表格。
OpenFileDialog opf = new OpenFileDialog(); //创建文件对话框
opf.Filter = "文本文件(*.txt)|*.txt";
if (opf.ShowDialog() == DialogResult.OK)
{
string rpath = opf.FileName; //获得文件地址
StreamReader sr = new StreamReader(rpath); //打开文件
int g_point_num = 0; //记录有多少已知点位
given_point gp = new given_point(); // 临时存放点位信息
while (!sr.EndOfStream)
{
string[] line = sr.ReadLine().Trim().Split(',', '，'); //读取文件，并分割到字符串数组中
if (line.Length == 2) //获得基准高程
{
height_datum = float.Parse(line[1]);
}
else if (line.Length == 4) //获得已知点信息
{
gp.point_name = line[0];
gp.X = float.Parse(line[1]);
gp.Y = float.Parse(line[2]);
gp.H = float.Parse(line[3]);
g_point.Add(gp); //把已知点放到列表中
datatable.Rows.Add(); //增加数据表格的列，并显示点位信息
datatable.Rows[g_point_num].Cells[0].Value = g_point[g_point_num].point_name;
datatable.Rows[g_point_num].Cells[1].Value = g_point[g_point_num].X;
datatable.Rows[g_point_num].Cells[2].Value = g_point[g_point_num].Y;
datatable.Rows[g_point_num].Cells[3].Value = g_point[g_point_num].H;
g_point_num++;
}
}
基准高程.Text = height_datum.ToString();
网格间隔.Text = grid_spacing.ToString();
status.Text = "导入数据";
}
}
catch
{
MessageBox.Show("输入文件有误，无法正确读取！");
}
datatable.BringToFront();
}
public List <given_point> get_convex_hull()
{
po_pn_sort();
Stack <point> c_h_point = new Stack <point>(); //建立栈
c_h_point.Push(p0);
c_h_point.Push(g_point[0]);
c_h_point.Push(g_point[1]);
int n = g_point.Count();
for (int i = 2; i < n; i++)
{
point top = c_h_point.Pop();
point sec_top = c_h_point.Peek();
c_h_point.Push(top);
if (judge_l_r(sec_top, top, g_point[i]) < 0)
{
c_h_point.Push(g_point[i]);
}
else
{
while (judge_l_r(sec_top, top, g_point[i]) > 0)
{
c_h_point.Pop();
top = top = c_h_point.Pop();
sec_top = c_h_point.Peek();
c_h_point.Push(top);
}
c_h_point.Push(g_point[i]);
}
}
c_h_point.Push(p0);
point[] c_h = c_h_point.ToArray();
List <given_point> return_point = new List <given_point>();
for (int i = c_h.Count() - 1; i >= 0; i--)
{
given_point point = new given_point();
point = c_h[i].p;
return_point.Add(point);
}
return(return_point);
}
void fun(List <given_point> left_point, given_point head, given_point tail) //迭代函数
{
int arcmax_sub = -1; //我们用三角形面积判断点的距离 ，得到最远点的序号，如果直线（头—尾）左边无点集，则把 尾 放入凸包点集中
double arcmax = 0;
for (int i = 0; i < left_point.Count; i++)
{
if (arc(head, tail, left_point[i]) > arcmax)
{
arcmax = arc(head, tail, left_point[i]); arcmax_sub = i;
}
}
if (arcmax_sub == -1)
{
conver_h.Add(tail);
}
else
{
given_point mid = left_point[arcmax_sub];
left_point.Remove(mid);
List <given_point> left_point1 = new List <given_point>(); //得到在直线（头—最远点）左边的点集
for (int j = 0; j < left_point.Count; j++)
{
if (judge_left(head, mid, left_point[j]) == 1)
{
left_point1.Add(left_point[j]);
}
}
fun(left_point1, head, mid);
List <given_point> left_point2 = new List <given_point>(); //得到在直线（最远点—尾）左边的点集
for (int j = 0; j < left_point.Count; j++)
{
if (judge_left(mid, tail, left_point[j]) == 1)
{
left_point2.Add(left_point[j]);
}
}
fun(left_point2, mid, tail);
}
}
private void get_V_Click(object sender, EventArgs e) //得到体积，并输出报告
{
if (g_point.Count == 0)
{
status.Text = "没有数据，无法计算"; return;
}
if (convex_hull.Count == 0)
{
this.生成凸包_Click(this, e);
}
given_point p0 = convex_hull[0]; //得到p0点
report.Text = "";
//计算体积信息
height_datum = float.Parse(基准高程.Text); //获得最新的基准高程和网格间隔信息
grid_spacing = float.Parse(网格间隔.Text);
diff_grid_size_report(1); //不同的网格间隔大小输出不同的报告
diff_grid_size_report(5);
diff_grid_size_report(10);
//输出报告：
report.Text = report.Text + "\r\n报告基点是:\r\n";
report.Text = report.Text + "点号 X坐标 Y坐标 H高程\r\n";
report.Text = report.Text + p0.point_name.PadRight(14) + p0.X.ToString().PadRight(14) +
p0.Y.ToString().PadRight(14) + p0.H.ToString().PadRight(15) + "\r\n";
report.Text = report.Text + "--------------------------凸包点----------------------\r\n";
report.Text = report.Text + "点号 X坐标 Y坐标 H高程\r\n";
for (int i = 0; i < convex_hull.Count(); i++)
{
report.Text = report.Text + convex_hull[i].point_name.PadRight(14) + convex_hull[i].X.ToString().PadRight(14) +
convex_hull[i].Y.ToString().PadRight(15) + convex_hull[i].H.ToString().PadRight(15) + "\r\n";
}
report.BringToFront();
status.Text = "生成报告";
}
double arc(given_point p1, given_point p2, given_point p3) //三点得到面积
{
return(Math.Abs((1.0 / 2) * (p1.X * (p2.Y - p3.Y) + p2.X * (p3.Y - p1.Y) + p3.X * (p1.Y - p2.Y))));
}
