Re: Emacs Mac port

[Eli Zaretskii]

> From: Stefan Monnier <address@hidden>
> Cc: Eli Zaretskii <address@hidden>,  address@hidden
> Date: Tue, 16 Apr 2013 09:20:15 -0400
> 
> > That shows a typical reason why recent toolkits treat the "expose"
> > handler as the primary drawing method.  By freshly redrawing
> > invalidated area in a rear-to-front way, it can provide some fancy
> > appearances such as overlapped/translucent widgets in a correct way.
> 
> So IIUC, the "new normal" way you describe goes something like:
> - redisplay builds glyph matrices from Lisp data and invalidates the
>   parts of the display that might need to be redrawn but does not draw.
> - expose handlers use the glyph matrices to draw on the screen
>   when/where needed.
> That makes a lot of sense.

Maybe I misunderstood, but I don't think the first item is accurate.
(And I don't think you can build glyph matrices, but not draw.)

I think the first step both draws _and_ invalidates, and then the
expose event redraws some small portion of the display.