This interface provides access to the ``animation clock'', the clock that is used to drive animations. Clients can inquire the current time, and can change the clock that is used. The default animation clock is a real-time clock; one particular alternative is ZeusClock.T, a clock that is controlled by the Zeus algorithm animation system.

INTERFACE Anim3D;

IMPORT Clock, Wr;

PROCEDURE Now () : LONGREAL;

Return the current value of the animation clock.

PROCEDURE ChangeClock (clock : Clock.T);

Let clock be the new animation clock. This procedure should not be called while an animation is in progress; terrible things might happen.

PROCEDURE SetErrorWr (wr : Wr.T);

Set the writer to which animation server error messages will be written to be wr. By default, error messages are written to Stdio.stderr.

VAR lock : MUTEX;

A client that wants to prevent the animation server from rendering an inconsistent scene should protect the critical section during which the scene is inconsistent by acquiring lock. Not acquiring lock will never crash a program. lock may not be held when ah.animate() is called for some animation handle ah.

END Anim3D.