#include <time.h>   // nanosleep()
 static struct timespec t={0.33*1000*1000}; // 33 mili seconds
 void mainloop()
 {
         // keep this in your mainloop. this will do smooth animations for you ...
         s3dw_ani_mate();
         nanosleep(&t,NULL);
 }
 ....
 s3d_mainloop(mainloop);