offscreen bm routines?

[Michael Travers <mt@media.mit.edu>]

There are a couple of packages on the MCL 2.0 CDROM:

Alan Ruttenberg's Sheet package extends MCL windows and views to allow
you to associate an offscreen gworld with a window and do
double-buffered drawing using the standard MCL view interface.

My own LiveWorld package is a simpler system oriented towards
sprite-based animation.  It too uses gworlds to do double-buffering,
but is not as tightly integrated into the MCL window system (for
better or worse, depending on what you are trying to do).