public double dot(Vec3 v)
{
return(x * v.x + y * v.y + z * v.z);
}
public Vec3 subtract(Vec3 v)
{
// doesn't modify
return(new Vec3(this.x - v.x, this.y - v.y, this.z - v.z));
}
public void add_update(Vec3 v)
{
// doesn't modify the calling vector
x += v.x; y += v.y; z += v.z;
}
public Vec3 add(Vec3 v)
{
// doesn't modify the calling vector
return(new Vec3(x + v.x, y + v.y, z + v.z));
}
public Vec3(Vec3 copy)
{
x = copy.x; y = copy.y; z = copy.z;
}
public Vec3 plane_normal(Vec3 C, Vec3 P)
{
return(C.subtract(P));
}