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From: rap@peck.ardent.com (Rob Peck)
Newsgroups: comp.sys.amiga
Subject: Re: Layers speed (was Re: 1.4 Wish: Revamped sizing gadget)
Message-ID: <8779@ardent.UUCP>
Date: 23 Oct 89 18:49:46 GMT
References: <5028@cps3xx.UUCP> <8221@cbmvax.UUCP>
Sender: news@ardent.UUCP
Reply-To: rap@peck.ardent.com (Rob Peck)
Organization: Ardent Computer Corp., Sunnyvale, CA
Lines: 27

In article <8221@cbmvax.UUCP> mks@cbmvax.UUCP (Michael Sinz - CATS) writes:
>In article <5028@cps3xx.UUCP> porkka@frith.UUCP (Joe Porkka) writes:
>>>Also, the extra layer activity will take much more time with MANY windows
>>>open on the screen.  (I have had many times when I had 15 to 20 windows of
>>>various types open on the workbench screen...)
>
The use of SMART_REFRESH does, at times, slow things down, but NOWHERE near
as much slowdown as when someone uses a GIMMEZEROZERO window.  The only
time I believe that such a window is necessary is when it is being used
to display a SUPERBITMAP window...

The nominal idea to GIMMEZEROZERO is that the upper lefthand corner of the
window's RastPort is 0,0 for drawing purposes instead of having to offset
for drawing to account for the top and left margin, as well as to manually
clip the drawing to the other bounds of the visible part of the window.
The necessary reason for the availability of a GIMMEZEROZERO window
is that it prevents Intuition from rendering its gadgets and borders
into the superbitmap.  Intuition does this by providing -->5<--- layers
totally, one for the drawable area, one for the top, bottom, left, and
right edges of the window.  THATS when operations on windows can really
get bogged down.

If a developer does not realize this, and uses a GIMMEZEROZERO when it is 
not needed, it slows everything down.  Talk about extra layer activity...
whew!!

Rob Peck