Vector2D& Vector2D::operator/=(double u)
{
if (!EQUALZERO(u))
{
x /= u; y /= u;
}
return(*this);
}
double calc_angle(double *u, double *v)
{
double ps;
double n1;
double n2;
double angle;
if (u == NULL || v == NULL)
return (0.001F);
angle = 0.0F;
ps = calc_ps(v, u);
n1 = calc_norme(u);
n2 = calc_norme(v);
if (!EQUALZERO(ps) && !EQUALZERO(n1) && !EQUALZERO(n2))
angle = ps / (n1 * n2);
angle = angle < 0.0000001 ? 0.00000 : angle;
return (angle);
}
short Vector2D::AtWhere(Vector2D v0,Vector2D v1)
{
Vector2D vTemp1(v1.y-v0.y,v0.x-v1.x);
Vector2D vTemp2(x-v0.x,y-v0.y);
double d=vTemp1*vTemp2;
if(EQUALZERO(d))
return 0;
if(d>0)//right
return 1;
return -1;
}
bool Vector2D::Intersect(Vector2D v1,Vector2D v2,Vector2D v3,Vector2D v4)//tow line intersect
{
double d=(v4.y-v3.y)*(v1.x-v2.x)-(v2.y-v1.y)*(v3.x-v4.x);
if(EQUALZERO(d))
return false;
double d1=v1.x*v2.y-v2.x*v1.y;
double d2=v3.x*v4.y-v4.x*v3.y;
x=((v4.x-v3.x)*d1-(v2.x-v1.x)*d2)/d;
y=((v4.y-v3.y)*d1-(v2.y-v1.y)*d2)/d;
return true;
}
