🚀 go-pugleaf

>You can do reasonable realtime operations (such as animation) under the
>current Mach kernel (Version 2.6 on NeXTs, I believe).

"Reasonable" realtime operations?  It's either realtime or it isn't.
Right now it isn't.

> Try looking at the DPSTimedEntry stuff.  There are examples from NeXT
> where at each frame, the animation code checks the actual time delay
> from the last frame, and generates the next frame accordingly.  This
> means that the frame rate is not constant, but animated objects have
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Then it's not realtime.  It would not be good enough, for example, for
controlling scientific instruments or operating CAM machinery.  And
often it would not be good enough for a lip-synched video that had
been digitized.  It'd look like a Saturday afternoon kung-fu movie.

> constant velocity and could be sync'ed reliably with sound.  This is
> generally acceptable if the CPU(s) can generate a reasonable frame
> rate considering the other loads on the system.

There's no way you can guarantee that.  On a workstation like the
NeXT, being sold to ordinary folks, the animation has to look good and
smooth *even* *if* they're running a heavy Mathematica process in the
background, or else it won't look good up against Macs and PCs with
this capability.
-- 
Doug DeJulio
ddj+@cmu.edu