Camera Class problem

class Camera{    public:        Camera ();        Camera (Vector3D eye, Vector3D lookat, Vector3D up);                /* Update the graphics device view matrix */        void set_viewMatrix ();        void set_viewport (int x0, int y0, int width, int height);        void set_viewShape (float fov_angle, float aspect_ratio, float znear, float zfar);                /* Modify camera */        void set_camera ();        void set_up ();        void roll_Camera (float theta);        void pitch_Camera (float theta);        void yaw_Camera (float theta);        /* Translate camera */        void slide_forward (float delta);        void slide_backward (float delta);        void slide_left (float delta);        void slide_right (float delta);        void slide_up (float delta);        void slide_down (float delta);        void slide_Camera (float du, float dv, float dn);        MATRIX_4X4 * setcamera ();        /* get the view and projection vectors */        Point3D * get_viewportParams () { return &viewport_params; }        MATRIX_4X4 * get_viewMtx () { return &viewMtx }// return &viewMtx }        MATRIX_4X4 * get_projectionMtx () { return &perspectiveMtx }            //private:        /* The three orientation vectors */        Vector3D cam_u, cam_v, cam_n, cam_up;                /* The origin and lookat points */        Vector3D cam_eye;        Vector3D cam_lookat;        Vector3D cam_translate;        /* Accumulation values */        float roll_theta, pitch_theta, yaw_theta, zoom_theta;        float u_delta, v_delta, n_delta;        /* The view and perspective matrices */        MATRIX_4X4 viewMtx;        MATRIX_4X4 perspectiveMtx;        /* The window to viewport parameters */        Point3D viewport_params;};

Camera::Camera (Vector3D eye, Vector3D lookat, Vector3D up){    cam_eye = eye;    cam_lookat = lookat;    cam_up = up; //(up.x, up.y, up.z);    /* Set the u, v and n states to well known values */    //set_default_uvn_state ();    /* Set all other values to zero */    zoom_theta = roll_theta = pitch_theta = yaw_theta = 0.0;    u_delta = v_delta = n_delta = 0.0;        mtx44_setidentity (&viewMtx);    mtx44_setidentity (&perspectiveMtx);        /* Update the view matrix */    set_camera();}void Camera::set_camera (){    //set_default_uvn_state ();    /* Step 1. Calculate and normalize the view direction vector */    cam_n = cam_eye - cam_lookat;    cam_n.normalize ();        /* Step 2. Calculate the real up vector (note - the given up vector may not be orthogonal to cam_n) */    cam_v = cam_up - ((cam_n * cam_up) * cam_n);    cam_v.normalize ();        /* Step 3. Calculate u (the side vector). To maintain right handedness, we calculate U = V * N */    /* also note that U is a unit vector by construction */    cam_u = cross_product (cam_v, cam_n);        /* Step 4. Calculate the translation component */    Vector3D trans_vector(-cam_eye.x, -cam_eye.y, -cam_eye.z);    cam_translate.set (trans_vector * cam_u,                       trans_vector * cam_v,                       trans_vector * cam_n);    /* Update the view matrix */    set_viewMatrix ();}void Camera::set_viewMatrix (){    viewMtx.m[0][0] = cam_u.x; viewMtx.m[0][1] = cam_v.x; viewMtx.m[0][2] = cam_n.x; viewMtx.m[0][3] = 0.0;    viewMtx.m[1][0] = cam_u.y; viewMtx.m[1][1] = cam_v.y; viewMtx.m[1][2] = cam_n.y; viewMtx.m[0][3] = 0.0;    viewMtx.m[2][0] = cam_u.z; viewMtx.m[2][1] = cam_v.z; viewMtx.m[2][2] = cam_n.z; viewMtx.m[0][3] = 0.0;    /* The translation row */    viewMtx.m[3][0] = cam_translate.x; viewMtx.m[3][1] = cam_translate.y; viewMtx.m[3][2] = cam_translate.z;    viewMtx.m[3][3] = 1.0;}void Camera::roll_Camera (float theta){    MATRIX_4X4 rmat;    mtx44_setidentity (&rmat);    /* rotation about the z axis */    //mtx44_rotationaxis (&rmat, cam_n, DEGREETO_RADS(theta));    mtx44_rotateZ (&rmat, DEGREETO_RADS(theta));    /* rotate both u and v */    mtxv14_multiply (&cam_u, &cam_u, &rmat);    /* then v */    mtxv14_multiply (&cam_v, &cam_v, &rmat);    /* then update the view matrix */    set_viewMatrix ();}void Camera::pitch_Camera (float theta){    MATRIX_4X4 pmat;    mtx44_setidentity (&pmat);    /* rotation about the z axis */    //mtx44_rotationaxis (&pmat, cam_u, DEGREETO_RADS(theta));    mtx44_rotateX (&pmat, DEGREETO_RADS(theta));    /* rotate both n and v */    mtxv14_multiply (&cam_n, &cam_n, &pmat);    /* then v */    mtxv14_multiply (&cam_v, &cam_v, &pmat);        /* then update the view matrix */    set_viewMatrix ();}void Camera::yaw_Camera (float theta){        MATRIX_4X4 ymat;    mtx44_setidentity (&ymat);    /* rotation about the z axis */    //mtx44_rotationaxis (&ymat, cam_v, DEGREETO_RADS(theta));    mtx44_rotateY (&ymat, DEGREETO_RADS(theta));    /* rotate both u and n */    mtxv14_multiply (&cam_u, &cam_u, &ymat);    /* then v */    mtxv14_multiply (&cam_n, &cam_n, &ymat);    /* then update the view matrix */    set_viewMatrix ();}void Camera::slide_forward (float du){    cam_translate.z += du;    set_viewMatrix ();}void Camera::slide_backward (float du){    cam_translate.z -= du;    set_viewMatrix ();}