void phi()
{
Point[] points_in_new_coord_where_Q_center = new Point[n];
int qx = Q.Value.X, qy = Q.Value.Y;
for (int i = 0; i < n; ++i)
{
points_in_new_coord_where_Q_center[i] = new Point(points_arr[i].X - qx, points_arr[i].Y - qy);
}
double [] phi_arr = new double[n];
for (int i = 0; i < n; ++i)
{
int x = points_in_new_coord_where_Q_center[i].X, y = points_in_new_coord_where_Q_center[i].Y;
double r = Math.Sqrt(x * x + y * y);
phi_arr[i] = Math.Asin(y) / r;
}
IEnumerable <Point> sort_enum_phi_arr; //
Point [] sort_phi_arr = new Point[n];
sort_enum_phi_arr = points_in_new_coord_where_Q_center.OrderBy(p => acos((p.X) / Math.Sqrt(p.X * p.X + p.Y * p.Y), p));
sort_phi_arr = sort_enum_phi_arr.ToArray();
}
private void button2_Click(object sender, EventArgs e) // алгоритм Грехема
{
if (n < 2)
{
label1.Text = "Введіть більше точок";
return;
}
label1.Text = "";
if (!Q.HasValue)
{
label1.Text = "Задайте внутрішню точку (правою кнопкою миші)";
return;
}
//polar_sort
// сортировка по полярному углу относительно точки Q
Point[] points_in_new_coord_where_Q_center = new Point[n];
int qx = Q.Value.X, qy = Q.Value.Y;
for (int i = 0; i < n; ++i)
{
points_in_new_coord_where_Q_center[i] = new Point(points_arr[i].X - qx, points_arr[i].Y - qy);
}
double[] phi_arr = new double[n];
for (int i = 0; i < n; ++i)
{
int x = points_in_new_coord_where_Q_center[i].X, y = points_in_new_coord_where_Q_center[i].Y;
double r = Math.Sqrt(x * x + y * y);
phi_arr[i] = Math.Asin(y) / r;
}
IEnumerable <Point> sort_enum_phi_arr; //
Point[] sort_phi_arr = new Point[n];
sort_enum_phi_arr = points_in_new_coord_where_Q_center.OrderBy(p => acos((p.X) / Math.Sqrt(p.X * p.X + p.Y * p.Y), p));
sort_phi_arr = sort_enum_phi_arr.ToArray();
// end_polar_sort
Point[] sort_points_arr = new Point[n];
for (int i = 0; i < n; ++i)
{
sort_points_arr[i] = new Point(sort_phi_arr[i].X + qx, sort_phi_arr[i].Y + qy);
}
bool[] is_ob = new bool[n];
is_ob.Initialize();
is_ob[0] = true;
is_ob[1] = true;
bool for_exit = false;
for (int i = 2; i < n; ++i)
{
is_ob[i] = true;
for (int j = i - 1; j > 0; --j)
{
if (is_ob[j])
{
for (int k = j - 1; k >= 0; --k)
{
if (is_ob[k])
{
for_exit = false;
if (point_is_left_AB(sort_points_arr[k], sort_points_arr[i], sort_points_arr[j]))
{
is_ob[j] = false;
for_exit = false;
}
else
{
for_exit = true;
}
break;
}
}
if (for_exit)
{
break;
}
}
}
}
//для последней точки (замыкающей)
int last_in_ob = 0;
for (int i = n - 2; i > 0; --i)
{
if (is_ob[i])
{
if (point_is_left_AB(sort_points_arr[i], sort_points_arr[0], sort_points_arr[n - 1]))
{
is_ob[n - 1] = false;
}
last_in_ob = i;
break;
}
}
for (int i = 1; i < n; ++i)
{
{
if (is_ob[i])
{
if (point_is_left_AB(sort_points_arr[last_in_ob], sort_points_arr[i], sort_points_arr[0]))
{
is_ob[0] = false;
}
}
break;
}
}
Draw();
Gl.glColor3d(0, 0, 1);
Gl.glPolygonMode(Gl.GL_FRONT_AND_BACK, Gl.GL_LINE);
Gl.glBegin(Gl.GL_POLYGON);
for (int i = 0; i < n; ++i)
{
if (is_ob[i])
{
Gl.glVertex2d(sort_points_arr[i].X, sort_points_arr[i].Y);
}
}
Gl.glEnd();
for (int i = 0; i < n; ++i)
{
Gl.glRasterPos2d(sort_phi_arr[i].X + qx, sort_phi_arr[i].Y + qy);
string text = (i + 1).ToString();
// в цикле foreach перебираем значения из массива text,
// который содержит значение строки для визуализации
foreach (char char_for_draw in text)
{
// визуализируем символ c, с помощью функции glutBitmapCharacter, используя шрифт GLUT_BITMAP_9_BY_15.
Glut.glutBitmapCharacter(Glut.GLUT_BITMAP_9_BY_15, char_for_draw);
}
}
Gl.glFlush();
AnT.Invalidate();
}
private void Ендрю_Джавірса_Click(object sender, EventArgs e)
{
if (n < 2)
{
label1.Text = "Введіть більше точок";
return;
}
label1.Text = "";
Point[] x_arr = new Point[n];
IEnumerable <Point> x_sort_enum;
Point[] x_sort;
for (int i = 0; i < n; ++i)
{
x_arr[i] = new Point(points_arr[i].X, points_arr[i].Y);
}
x_sort_enum = x_arr.OrderBy(p => p.X);
x_sort = x_sort_enum.ToArray();
Point left = new Point(x_sort[0].X, x_sort[0].Y);
Point right = new Point(x_sort[n - 1].X, x_sort[n - 1].Y);
int n_up = 0, n_down = 0;
Point[] up = new Point[n];
Point[] down = new Point[n];
int iup = 0, idown = 0;
up[iup++] = new Point(left.X, left.Y);
down[idown++] = new Point(left.X, left.Y);
// верхний и нижний массивы
foreach (Point p in x_sort)
{
if (point_is_left_AB(left, right, p))
{
up[iup++] = new Point(p.X, p.Y);
}
else if (point_is_right_AB(left, right, p))
{
down[idown++] = new Point(p.X, p.Y);
}
}
up[iup++] = new Point(right.X, right.Y);
down[idown++] = new Point(right.X, right.Y);
bool[] in_ob_up = new bool[iup];
bool[] in_ob_down = new bool[idown];
in_ob_up.Initialize();
in_ob_down.Initialize();
in_ob_up[0] = true;
in_ob_up[iup - 1] = true;
in_ob_down[0] = true;
in_ob_down[idown - 1] = true;
// обработка верхнего
for (int i = 0; i < iup - 1;)
{
int index_of_max_angle = index_max_angle_up(iup, up, i);
in_ob_up[index_of_max_angle] = true;
i = index_of_max_angle;
}
//обработка нижнего массива
for (int i = 0; i < idown - 1;)
{
int index_of_max_angle = index_max_angle_down(idown, down, i);
in_ob_down[index_of_max_angle] = true;
i = index_of_max_angle;
}
// рисуем
Draw();
Gl.glPolygonMode(Gl.GL_FRONT_AND_BACK, Gl.GL_LINE);
Gl.glBegin(Gl.GL_POLYGON);
Gl.glColor3d(1, 0, 0);
for (int i = 0; i < iup; ++i)
{
if (in_ob_up[i])
{
Gl.glVertex2d(up[i].X, up[i].Y);
}
}
Gl.glColor3d(0, 0, 1);
for (int i = idown - 1; i >= 0; --i)
{
if (in_ob_down[i])
{
Gl.glVertex2d(down[i].X, down[i].Y);
}
}
Gl.glEnd();
AnT.Invalidate();
Gl.glFlush();
return;
}