public static boolean isIntersect(Vector A1, Vector A2, Vector B1, Vector B2) {
Vector A = diff(A1, A2);
Vector B = diff(B2, B1);
Vector C = diff(B2, A2);
double determinant = A.getA() * B.getB() - A.getB() * B.getA();
double d1 = C.getA() * B.getB() - C.getB() * B.getA();
double d2 = A.getA() * C.getB() - A.getB() * C.getA();
if (determinant == 0 && d1 == 0 && d2 == 0) return true;
if (determinant == 0) return false;
double k1 = d1 / determinant;
double k2 = d2 / determinant;
return k1 >= 0 && k1 <= 1 && k2 >= 0 && k2 <= 1;
}
public static double length(Vector vector) {
return Math.sqrt(vector.getA() * vector.getA() + vector.getB() * vector.getB());
}
public static Vector diff(Vector v1, Vector v2) {
return new Vector(v1.getA() - v2.getA(), v1.getB() - v2.getB());
}
public static Vector normal(Vector v) {
return new Vector(-v.getB(), v.getA());
}
public static double vectorProd(Vector v1, Vector v2) {
return v1.getA() * v2.getB() - v1.getB() * v2.getA();
}
public static double scalarProd(Vector v1, Vector v2) {
return v1.getA() * v2.getA() + v1.getB() * v2.getB();
}
public static Vector sum(Vector meToEnemy, Vector me) {
return new Vector(meToEnemy.getA() + me.getA(), meToEnemy.getB() + me.getB());
}
public static Vector prod(Vector vector, double scalar) {
return new Vector(vector.getA() * scalar, vector.getB() * scalar);
}
public static Vector rotate(Vector vector, double angle) {
double a = vector.getA();
double b = vector.getB();
return new Vector(a * cos(angle) - b * sin(angle), a * sin(angle) + b * cos(angle));
}
