Code:

void Q3Map::Render(const Camera& cam, float frame_time)
{
    // pronadji klaster koji sadrzi kameru
    m_pCurCam = &cam;
    int leaf_i = FindLeaf(cam.GetPosition());
    m_nCurCamCluster = m_leaves[leaf_i].cluster;

    // prodji kroz BSP stablo i iscrtaj sve vidljive poligone
    // od najdaljeg do najblizeg
    m_vis_faces_map.Reset();
    RenderNode(0);
}

void Q3Map::RenderNode(int node_i)
{
    Node& node = m_nodes[node_i];
    if(node_i >= 0){
        // da li je kamera ispred ravni u trenutnom cvoru?
        if(PointToPlaneEval(m_pCurCam->GetPosition(), m_planes[node.plane]) >= 0){
            RenderNode(node.back);
            RenderNode(node.front);
        }
        else{
            RenderNode(node.front);
            RenderNode(node.back);
        }
    }
    else{
        int leaf_i = ~node_i;
        // iscrtaj list
        Leaf& leaf = m_leaves[leaf_i];
        if(IsClusterVisible(m_nCurCamCluster, leaf.cluster)){
            fVect3 bbox_min(leaf.mins), bbox_max(leaf.maxs);
            if(m_pCurCam->IsBBoxVisible(bbox_min, bbox_max)){
                int last_leafface = leaf.leafface + leaf.num_leaffaces - 1;
                for(int i = leaf.leafface; i <= last_leafface; ++i){
                    int face_i = m_leaf_faces[i];
                    Face& face = m_faces[face_i];
                    if(face.type == FT_POLYGON){
                        if(!m_vis_faces_map.IsSet(face_i)){
                            m_vis_faces_map.Set(face_i);

                            // iscrtaj ovaj poligon
                            glActiveTextureARB(GL_TEXTURE0_ARB);
                            m_texs[face.texture].MakeCurrent();
                            glEnable(GL_TEXTURE_2D);
                            glActiveTextureARB(GL_TEXTURE1_ARB);
                            m_lmap_texs[face.lmap_index].MakeCurrent();
                            glEnable(GL_TEXTURE_2D);
                            glDrawArrays(GL_TRIANGLE_FAN, face.vertex, face.num_vertices);
                        }
                    }
                }
            }
        }
    }
}