while (elapsed_time >= 0.0 && (how_long < 0.0 || 0.00001 < (how_long -total_time)) &&
!sd_global->watch_point_reached) {
surf_model_t model = NULL;
while (elapsed_time >= 0.0 && (how_long < 0.0 || 0.00001 < (how_long -total_time)) &&
!sd_global->watch_point_reached) {
surf_model_t model = NULL;