draw-glyph

[Palter@STONY-BROOK.SCRC.Symbolics.COM (Gary M. Palter)]

    Date: Fri, 15 Nov 1991 12:00 EST
    From: WJL@ZERMATT.lcs.mit.edu (Bill Long)

    Quick question:

    I took my code that was running on a 3650 under 8.0.1 and tried it on a
    MacIvory running 8.1.1.  Mostly it worked great -- about a 4x speedup.
    I did run into two minor problems:

    1) (graphics:draw-glyph (char-code #\A) fonts:mouse 
	    x (- y #.(tv:font-char-height fonts:mouse))
	    :stream window)
    now puts the character up in the air but
       (graphics:draw-glyph (char-code #\A) fonts:mouse 
	    x (+ y #.(tv:font-char-height fonts:mouse))
	    :stream window)
    puts the baseline where I want it.  The sign of
    (tv:font-char-height fonts:mouse) hasn't changed, so apparently
    graphics:draw-glyph has changed.  (The font is one I customized back in
    version 6 days.)  Is this change due to the MacIvory (in which case I
    can use #+imach) or due to 8.1 (in which case ??)?

This behavior is a bug that was introduced in Genera 8.1.1.
You should contact Software Support for the fix.

    2) I also noticed that my diagrams, drawn on a pane defined as a flavor
    of tv:window-pane with :save-bits t (version 6 stuff), gets wiped out by
    the Mac screen saver.  Anything easy I can do (other than bringing my
    code into the 1990's)?  (I already thought of turning off the screen
    saver.)

There's a feature in the Genera application to make such old style
windows refresh properly.  You'll find it in the Options menu; it's
called "Enable Backup Screen".  Be warned, however, that enabling a
backup screen will slow down Lisp's window system as the Macintosh will
be doing all your drawing operations twice.  With a IIfx, you shouldn't
notice; with anything older, however, you will see the difference.

The variables RPC:*RPC-SCREEN-USE-BACKUP-SCREEN* and 
RPC:*RPC-SCREEN-ALWAYS-USE-BACKUP-SCREEN* can be used to control the
setting of this feature when you launch the Genera application.  If the
second variable is non-NIL, in addition to enabling the backup screen
feature, the menu item will be removed from the Options menu.
Unfortunately, there's no simple way to programatically enable the
feature after launching the Genera application.

    Thanks for your help.

    -Bill Long