q_axis_angle( qflip, (v3f){0.0f,1.0f,0.0f}, VG_PIf );
q_mul( gate->q[0], qflip, gate->q[0] );
q_mul( gate->q[1], qflip, gate->q[1] );
q_axis_angle( qflip, (v3f){0.0f,1.0f,0.0f}, VG_PIf );
q_mul( gate->q[0], qflip, gate->q[0] );
q_mul( gate->q[1], qflip, gate->q[1] );