Re: ROM 3 mouse/QuickDraw Q

[dlyons@Apple.COM (David A Lyons)]

In article <jmk3.720127524@crux1.cit.cornell.edu> jmk3@crux2.cit.cornell.edu (Jay M. Krell) writes:
[...]
>But isn't GetNextEvent somewhat reentrant? CDA's can get control during
>GetNextEvent and they can call it, can't they?

Yes, it's reentrant in that particular controlled way.  But it's not fully
reentrant; it's not safe to call from an interrupt.

CDAs are okay calling GetNextEvent because when the Event Manager is active
the CDA menu always gets called in a safe way from inside GetNextEvent--the
Command-Ctrl-Esc interrupt just posts an event to be handled later.


>Toolbox Ref II says a GrafPort's width (bytes) has to be an even multiple of
>8. I know even numbers allow optimization and all, but requiring a multiple of
>16 seems a bit severe. I see that when drawing an arrow in 320 mode, the Menu
>Manager calls PPToPort with a GrafPort with a width of 4. I didn't find the 640
>mode call yet. So, the question is, are the docs right or is the restriction
>less severe?

First:  I believe the phrase "even multiple of 8" is intended to mean "exact
multiple of 8".

Without going over the entire QuickDraw & QD Aux source with an extremely
careful comb, I can't promise that anything less strict than is documented
will work (even if the system uses a less strict rule in some cases).  The
safe thing is to stick with multiples of 8 for the width.


>Will 6.0.1 include newPort and killPort from the DTS Lib that originally had
>PixelMap2Rgn?

No...we almost put them into 6.0, but eventually decided it wasn't worth
it (taking up disk space and RAM space even though most programs would not
be using them).  They still work fine as library routines.  (Was the source
code available with the DTS sample code?  If not, I bet that could be
arranged.  Not for PixelMap2Rgn, but for newPort and killPort.)
-- 
David A. Lyons, Apple Computer, Inc.      |   DAL Systems
Apple II System Software Engineer         |   P.O. Box 875
Internet:dlyons@apple.com                 |   Cupertino, CA 95015-0875

My opinions are my own, not Apple's.