public float[] VectorTo(Cord T)
{
return(new float[2]
{
x - T.x,
y - T.y
});
}
private void Set(Cord A, Cord B, Cord C)
{
this.A = A.GetCord();
this.B = B.GetCord();
this.C = C.GetCord();
this.BC = B.Distance(C);
this.AC = A.Distance(C);
this.AB = A.Distance(B);
}
static void Main(string[] args)
{
Cord c = new Cord();
Cord b = new Cord(5, 0);
Cord a = new Cord(0, 5);
Triangle tr1 = new Triangle(a, b, c);
Triangle tr2 = new Triangle(new Cord(1, 1), new Cord(1, 5), new Cord(4, 1));
tr1.Display("Tr1");
tr2.Display("TR2");
Console.WriteLine("TR1 == TR2 ? " + tr1.EqualTr(tr2));
tr2.Rotation('A', 60);
tr2.Display("Tr2");
tr2.Rotation('A', -60);
tr2.Display("Tr2");
Console.ReadKey();
}
/// <summary>
/// Повертає трикутник навколо точки pointName: (A,B,C, O - центр описаного кола) на кут angle в градусах
/// </summary>
/// <returns></returns>
public void Rotation(char pointName, int angle)
{
Console.WriteLine($"Rotation by a {angle} degrees relative to a point \'" + pointName + "\'.");
Cord centerOfRotation;
switch (pointName)
{
case 'A':
case 'a':
centerOfRotation = A.GetCord();
break;
case 'B':
case 'b':
centerOfRotation = B.GetCord();
break;
case 'C':
case 'c':
centerOfRotation = C.GetCord();
break;
case 'O':
case 'o':
float znam = 2 * (A.X * (B.Y - C.Y) + B.X * (C.Y - A.Y) + C.X * (A.Y - B.Y));
float x = (A.Y * DSSC(B, C) + B.Y * DSSC(C, A) + C.Y * DSSC(A, B)) / (-2 * znam);
float y = (A.X * DSSC(B, C) + B.X * DSSC(C, A) + C.X * DSSC(A, B)) / znam;
centerOfRotation = new Cord(x, y);
break;
default: return;
}
float cos_angle = (float)Math.Cos(angle * Math.PI / 180);
float sin_angle = (float)Math.Sin(angle * Math.PI / 180);
float Ax = centerOfRotation.X + (A.X - centerOfRotation.X) * cos_angle - (A.Y - centerOfRotation.Y) * sin_angle;
float Ay = centerOfRotation.Y + (A.Y - centerOfRotation.Y) * cos_angle + (A.X - centerOfRotation.X) * sin_angle;
float Bx = centerOfRotation.X + (B.X - centerOfRotation.X) * cos_angle - (B.Y - centerOfRotation.Y) * sin_angle;
float By = centerOfRotation.Y + (B.Y - centerOfRotation.Y) * cos_angle + (B.X - centerOfRotation.X) * sin_angle;
float Cx = centerOfRotation.X + (C.X - centerOfRotation.X) * cos_angle - (C.Y - centerOfRotation.Y) * sin_angle;
float Cy = centerOfRotation.Y + (C.Y - centerOfRotation.Y) * cos_angle + (C.X - centerOfRotation.X) * sin_angle;
Set(new Cord(Ax, Ay), new Cord(Bx, By), new Cord(Cx, Cy));
}
public float Distance(Cord T)
{
return((float)Math.Sqrt(Math.Pow(T.x - this.x, 2) + Math.Pow(T.y - this.y, 2)));
}
/// <summary>
/// difference of the sum of squares of coordinates: повертає різницю між сумю кватратів координат точки Т1 та Т2
/// </summary>
/// <returns></returns>
private float DSSC(Cord T1, Cord T2)
{
return(T1.X * T1.X + T1.Y * T1.Y - T2.X * T2.X - T2.Y * T2.Y);
}
public Triangle(Cord A, Cord B, Cord C)
{
Set(A, B, C);
}