//расчет угла между отрезками
public double VectorAng(segments seg1, segments seg2)
{
double x1 = Math.Abs(seg1.x1 - seg1.x2);
double x2 = Math.Abs(seg2.x1 - seg2.x2);
double y1 = Math.Abs(seg1.y1 - seg1.y2);
double y2 = Math.Abs(seg2.y1 - seg2.y2);
double CosA = (x1 * x2 + y1 * y2) / (Math.Sqrt(Math.Pow(x1, 2) + Math.Pow(y1, 2)) * Math.Sqrt(Math.Pow(x2, 2) + Math.Pow(y2, 2)));
double ACosA = Math.Acos(CosA);
return(ACosA);
}
//Добавление вектора
public void AddVector(int x1, int x2, int y1, int y2)
{
segments NewSeg = new segments()
{
x1 = Convert.ToInt32(x1),
x2 = Convert.ToInt32(x2),
y1 = Convert.ToInt32(y1),
y2 = Convert.ToInt32(y2),
Name = ("(" + x1 + ";" + y1 + ")(" + x2 + ";" + y2 + ")")
};
db.segments.Add(NewSeg);
db.SaveChanges();
}
//пересчет координат вектора, в зависимоти от угла и точки поворота
public void Rotate(double angle, segments seg1, double X, double Y)
{
/*
* X = x * cos(alpha) — y * sin(alpha);
* Y = x * sin(alpha) + y * cos(alpha);
*/
double angleRadian = angle * Math.PI / 180;
double OX1 = seg1.x1, OY1 = seg1.y1, OX2 = seg1.x2, OY2 = seg1.y2;
seg1.x1 = (OX1 - X) * Math.Cos(angleRadian) - (OY1 - Y) * Math.Sin(angleRadian) + X;
seg1.y1 = (OX1 - X) * Math.Sin(angleRadian) + (OY1 - Y) * Math.Cos(angleRadian) + Y;
seg1.x2 = (OX2 - X) * Math.Cos(angleRadian) - (OY2 - Y) * Math.Sin(angleRadian) + X;
seg1.y2 = (OX2 - X) * Math.Sin(angleRadian) + (OY2 - Y) * Math.Cos(angleRadian) + Y;
}
//определяет наличие или отсутствие пересечений
public bool Intersection(segments seg1, segments seg2)
{
double x1, x2, x3, x4, y1, y2, y3, y4;
double Ua, Ub, numerator_a, numerator_b, denominator;
if (seg1.x2 <= seg1.x1)
{
x1 = seg1.x2;
x2 = seg1.x1;
y1 = seg1.y2;
y2 = seg1.y1;
}
else
{
x1 = seg1.x1;
x2 = seg1.x2;
y1 = seg1.y1;
y2 = seg1.y2;
}
if (seg2.x2 <= seg2.x1)
{
x3 = seg2.x2;
x4 = seg2.x1;
y3 = seg2.y2;
y4 = seg2.y1;
}
else
{
x3 = seg2.x1;
x4 = seg2.x2;
y3 = seg2.y1;
y4 = seg2.y2;
}
denominator = (y4 - y3) * (x1 - x2) - (x4 - x3) * (y1 - y2);
if (denominator == 0)
{
if ((x1 * y2 - x2 * y1) * (x4 - x3) - (x3 * y4 - x4 * y3) * (x2 - x1) == 0 && (x1 * y2 - x2 * y1) * (y4 - y3) - (x3 * y4 - x4 * y3) * (y2 - y1) == 0)
{
return(true);
}
else
{
return(false);
}
}
else
{
numerator_a = (x4 - x2) * (y4 - y3) - (x4 - x3) * (y4 - y2);
numerator_b = (x1 - x2) * (y4 - y2) - (x4 - x2) * (y1 - y2);
Ua = numerator_a / denominator;
Ub = numerator_b / denominator;
if (Ua >= 0 && Ua <= 1 && Ub >= 0 && Ub <= 1)
{
return(true);
}
else
{
return(false);
}
}
}