Re: regions

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

    In working on a molecular graphics application that demands animation, I
    find myself wanting to do offscreen drawing with quick display of the
    results. After hours of manual pondering and experimentation, I'm
    mystified.
    
    1) Is there a standard way to do this other than to use regions?

You probably want to use GWorlds, which are offscreen drawing
environments (that is, they provide a way to create an offscreen
pixmap that you can draw into).  There are a number of
user-contributed code packages that let you work with them.  I have a
rather minimal package that uses GWorlds for sprite animation, which
is in mt-lisp-contribs on the Apple Cambridge FTP site.  Alan
Ruttenberg has written a more elaborate system called Sheets which
integrates GWorlds into the MCL view system.  Both let you do
offscreen drawing and double-buffered animation.