Class attribute incorrect value C++ - c++

Question

EDIT: To initialize the position array m_pos[3] I set all it's values to 0 in the constructor and then I call from the main function another function called SetPos() which only sets the position of the planet in the 3D map:
void SetPos(float x, float z);
void Planet::SetPos(float x, float z)
{
m_pos[0]=x;
m_pos[1]=0;
m_pos[2]=y;
}
Thus, the constructor takes the form:
Planet::Planet()
{
m_pos[0]=0;
m_pos[1]=0;
m_pos[2]=0;
}
Is that a bad way to do it? (by need, i can't set the position directly through the constructor).
ORIGINAL:
I've created a class called Planet which controles a series of planets (Planet object) in a map. Each object has an array pos[3] which stores the coordinates where the planet must be drawn.
The planets also own a function called DrawConnections() which is in charge of drawing lines representing the connections between the actual planet and the other planets. The planets that one planet is connected to are stored in a vector, std::vector<Planet> connections.
Since attributes are encapsulated, there's a function in the Planet class which returns the position of the planet, called GetPos(float* pos), where *pos is a pointer to an array capable of storing the position of the planet.
First things first, those are the prototypes and variable declarations from Planet.h file:
public:
void DrawConnections(float radius);
void GetPos(float* position);
private:
float m_pos[3];
std::vector<Planet> m_connection;
The function DrawConnections() from Planet.cpp looks like this:
void Planet::DrawConnections(float radius) //parameter radius controls width of lines
{
float position[3]={0.0f,0.0f,0.0f}; //array storing the position of the planets
//which we are connecting to
//various OpenGl calls go here
glBegin(GL_LINES); //begins drawing the lines
for(int i=0;i<m_connection.size();i++) //for each planet we are connected to, draw a
//line
{
glVertex3f(m_pos[0],m_pos[1],m_pos[2]); //draws the first point of the line in the
//actual planet
m_connection[i].GetPos(position); //Gets the position of the planet we connect to
glVertex3f(position[0],position[1],position[2]); //draws the second point of the
//in the planet we connect to
}
glEnd(); //ends drawing
//some other OpenGl calls
}
The function GetPos() from Planet.cpp looks like this:
void Planet::GetPos(float* position)
{
position[0]=m_pos[0]; //copies the data from the position array to
position[1]=m_pos[1]; //the given pointer
position[2]=m_pos[2];
}
Any planet has x, neither z, 0 coordinate. Each one of them has a set of (x,y,z) coordinates, with x and z always different to 0.
However, some of the calls to GetPos() return x and z equal to 0, while others work properly.
This results in many lines going from the planets to the bottom left corner of the screen, without representing any connection. From what I've figured out I think the problem is in the GetPos(). However, other similar drawing functions also use GetPos() and work perfectly when they're called before the DrawConnection() function, but seem to be affected when they're called once DrawConnections() has been called It is as if that one was modifying the values of the position array when called and thus disturbing everything else which has to be with the position, including herself.
As an additional information, I'm working with Codeblocks and the MinGW GNU GCC compiler. I appreciate any help that you could give me.

Answer 1

Why not do?
public:
void DrawConnections(float radius);
const std::vector<float>& GetPos() const {return m_pos;};
private:
std::vector<float> m_pos;
std::vector<Planet> m_connection;