Gan_Camera CameraD; /* double precision camera */
Gan_Camera_f CameraF; /* single precision camera */
/* ... build CameraD using e.g. gan_cameraf_build_linear() ... */
/* convert camera from double precision to single precision */
gan_cameraf_from_camera_q ( &CameraD, &CameraF ); /* OR */
CameraF = gan_cameraf_from_camera_s ( &CameraD );
/* convert camera back from single precision to double precision */
gan_camera_from_cameraf_q ( &CameraF, &CameraD ); /* OR */
CameraD = gan_camera_from_cameraf_s ( &CameraF );