Weird bug when trying to Generate vertices for a hollow Circle

Hi everyone was just messing around trying to create a makeshift planetary system and I have created the planets (Cubes). But when trying to generate new vertices for the Orbits (Hollow Circle), it justs gives me a blank screen :frowning: any help would be appreciated! The black screen comes out immediately when I call generate_orbit() without even adding it to any of the buffers :tired:
Thanks in advance!

struct Vertex //Basic struct to store the Vertex info
    GLfloat position[3];
    GLfloat color[3];

void generate_orbit(float centreX, float centreY, float centreZ, float circleRadius)
    float angle = PI * 2 / static_cast<float>(orbit_slices);    // used to generate x and y coordinates
                                                                // generate vertex
    for (int i = 0; i < orbit_slices + 2; i++)
        // multiply by 3 because a vertex has x, y, z coordinates

        g_orbitVertices[i].position[0] = circleRadius * cos(angle) + centreX;
        g_orbitVertices[i].color[0] = 1.0f;
        g_orbitVertices[i].position[1] = circleRadius * sin(angle) + centreY;
        g_orbitVertices[i].color[1] = 0.0f;
        g_orbitVertices[i].position[2] = circleRadius + centreZ;
        g_orbitVertices[i].color[2] = 0.0f;
        // update to next angle
        angle += PI * 2 / static_cast<float>(orbit_slices);