private static double getArea(Puncte A, Puncte B, Puncte C)
{
double s = A.x * B.y - A.y * B.x;
s += B.x * C.y - B.y * C.x;
s += C.x * A.y - C.y * A.x;
return(Math.Abs(s));
}
private static void getMaxX(int n, Puncte[] P, Puncte nowP)
{
maxX = nowP.x;
for (int i = 1; i <= n; ++i)
{
if (cmp(maxX, Math.Abs(P[i].x)) < 0)
{
maxX = P[i].x;
}
}
}
private static void getMaxY(int n, Puncte[] P, Puncte nowP)
{
maxY = nowP.y;
for (int i = 1; i <= n; ++i)
{
if (cmp(maxY, Math.Abs(P[i].y)) < 0)
{
maxY = P[i].y;
}
}
}
public static void init(ref int n, Puncte[] P, Puncte nowP, int new_W, int new_H, Graphics g)
{
W = new_W / 2 - 7;
H = new_H / 2 - 33;
getMaxX(n, P, nowP);
getMaxY(n, P, nowP);
int pos = 1;
ldP = P[1];
for (int i = 2; i <= n; ++i)
{
if (cmpPuncte(P[i], ldP) < 0)
{
pos = i;
ldP = P[i];
}
}
ldPP = new Puncte(ldP.x, ldP.y);
p = new Puncte(nowP.x, nowP.y);
for (int i = pos; i < n; ++i)
{
P[i] = P[i + 1];
}
--n;
Array.Sort(P, 1, n, new cmpSlope());
PP = new Puncte[n + 1];
for (int i = 1; i <= n; ++i)
{
PP[i] = new Puncte(P[i].x, P[i].y);
}
if (maxX > W || maxY > H)
{
decrease(n, P);
}
else
{
increase(n, P);
}
translate(n, P);
drawPolygon(n, P, g);
/*
* Pen blackPen = new Pen(Color.Black, 1);
* g.DrawLine(blackPen, W, 0, W, H);
* g.DrawLine(blackPen, W, 2 * H, W, H);
* g.DrawLine(blackPen, 0, H, W, H);
* g.DrawLine(blackPen, 2 * W, H, W, H);
*/
}
public static string solve(int n, Puncte nowP)
{
if (Math.Abs(det(ldPP, PP[1], nowP)) < eps)
{
return("Punctul se afla pe dreapta determinata de punctele: (" + ldPP.x + ", " + ldPP.y + "), (" +
PP[1].x + ", " + PP[1].y + ")!");
}
for (int i = 1; i < n; ++i)
{
if (Math.Abs(det(PP[i], PP[i + 1], nowP)) < eps)
{
return("Punctul se afla pe dreapta determinata de punctele: (" + PP[i].x + ", " + PP[i].y + "), (" +
PP[i + 1].x + ", " + PP[i + 1].y + ")!");
}
}
if (Math.Abs(det(PP[n], ldPP, nowP)) < eps)
{
return("Punctul se afla pe dreapta determinata de punctele: (" + PP[n].x + ", " + PP[n].y + "), (" +
ldPP.x + ", " + ldPP.y + ")!");
}
int lt = 0, rt = n + 1;
while (rt - lt > 1)
{
int mid = (lt + rt) / 2;
double cs = cross_slope(ldPP, nowP, PP[mid]);
if (cs < -getEps())
{
rt = mid;
}
else
{
lt = mid;
}
}
if (lt == 0 || rt == n + 1)
{
return("Punctul se afla in exteriorul poligonului!");
}
double t1 = getArea(ldPP, nowP, PP[lt]);
double t2 = getArea(PP[lt], nowP, PP[rt]);
double t3 = getArea(PP[rt], nowP, ldPP);
double t = getArea(ldPP, PP[lt], PP[rt]);
if (Math.Abs(t1 + t2 + t3 - t) < eps)
{
return("Punctul se afla in interiorul poligonului");
}
return("Punctul se afla in exteriorul poligonului!");
}
public Form3(int n, Puncte[] P, Puncte nowP)
{
InitializeComponent();
this.n = n;
this.nowP = new Puncte(nowP.x, nowP.y);
this.P = new Puncte[this.n + 1];
for (int i = 1; i <= n; ++i)
{
this.P[i] = new Puncte(P[i].x, P[i].y);
}
}
public static void drawDiagonals(int n, Puncte[] P, Puncte nowP, Graphics g)
{
Pen redPen = new Pen(Color.Red, 1);
g.DrawLine(redPen, (float)ldP.x + 1, (float)ldP.y + 1, (float)P[1].x + 1, (float)P[1].y + 1);
for (int i = 1; i < n; ++i)
{
g.DrawLine(redPen, (float)ldP.x + 1, (float)ldP.y + 1, (float)P[i].x + 1, (float)P[i].y + 1);
}
g.DrawLine(redPen, (float)P[n].x + 1, (float)P[n].y + 1, (float)ldP.x + 1, (float)ldP.y + 1);
Pen bluePen = new Pen(Color.Blue, 1);
bluePen.DashStyle = System.Drawing.Drawing2D.DashStyle.DashDot;
g.DrawLine(bluePen, (float)ldP.x + 1, (float)ldP.y + 1, (float)p.x + 1, (float)p.y + 1);
}
public static int cmpPuncte(Puncte A, Puncte B)
{
if (A.x - B.x < -getEps())
{
return(-1);
}
else if (A.x - B.x > getEps())
{
return(1);
}
else
{
if (A.y - B.y < -getEps())
{
return(-1);
}
else if (A.y - B.y > getEps())
{
return(1);
}
}
return(0);
}
public static double cross_slope(Puncte A, Puncte B, Puncte C)
{
return((A.y - B.y) * (A.x - C.x) - (A.y - C.y) * (A.x - B.x));
}
private static double det(Puncte A, Puncte B, Puncte C)
{
return(A.x * B.y + B.x * C.y + C.x * A.y
- C.x * B.y - A.x * C.y - B.x * A.y);
}
private void button1_Click(object sender, EventArgs e)
{
if (i == n + 1)
{
try
{
string sX = textBoxX.Text;
string sY = textBoxY.Text;
if (sX.Length == 0)
{
MessageBox.Show("Va rugam sa introduceti un numar intre [1, 10^5]!", "Error!");
textBoxX.Text = "";
return;
}
if (sY.Length == 0)
{
MessageBox.Show("Va rugam sa introduceti un numar intre [1, 10^5]!", "Error!");
textBoxY.Text = "";
return;
}
double x = Convert.ToDouble(sX);
double y = Convert.ToDouble(sY);
nowP = new Puncte(x, y);
Form3 form3 = new Form3(n, P, nowP);
form3.Show();
Hide();
}
catch
{
MessageBox.Show("Va rugam sa introduceti un numar intre [1, 10^5]!", "Error!");
textBoxX.Text = "";
textBoxY.Text = "";
}
}
if (i <= n)
{
try
{
string sX = textBoxX.Text;
string sY = textBoxY.Text;
if (sX.Length == 0)
{
MessageBox.Show("Va rugam sa introduceti un numar intre [1, 10^5]!", "Error!");
textBoxX.Text = "";
return;
}
if (sY.Length == 0)
{
MessageBox.Show("Va rugam sa introduceti un numar intre [1, 10^5]!", "Error!");
textBoxY.Text = "";
return;
}
double x = Convert.ToDouble(sX);
double y = Convert.ToDouble(sY);
P[i] = new Puncte(x, y);
if (i < n)
{
punctLabel.Text = "Punctul " + Convert.ToString(i + 1) + ":";
}
else
{
punctLabel.Text = "Punct: ";
}
textBoxX.Text = "";
textBoxY.Text = "";
++i;
}
catch
{
MessageBox.Show("Va rugam sa introduceti un numar intre [1, 10^5]!", "Error!");
textBoxX.Text = "";
textBoxY.Text = "";
}
}
}
