Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!mcsun!ukc!dcl-cs!gdt!gdr!mapjilg
From: mapjilg@gdr.bath.ac.uk (J I L Gold)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Double-Buffering in a window
Message-ID: <1990Jan4.104416.15515@gdt.bath.ac.uk>
Date: 4 Jan 90 10:44:16 GMT
References: <885@mindlink.UUCP>
Reply-To: mapjilg@gdr.bath.ac.uk (J I L Gold)
Organization: University of Bath, England
Lines: 26

In article <885@mindlink.UUCP> a464@mindlink.UUCP (Bruce Dawson) writes:
>
>     Screens are hardware entities, consisting of a set of rectangular (as
>rectangular as a linear chunk of memory can be) bit planes.  They can be moved
>by adjusting pointers into the copper list so as to adjust pointers in the
>display chip.
>
>     Windows are software entities.  The illusion of hidden portions of windows
>and the ability to move windows around is done completely by the grunt method
>of picking up data and moving it, and storing hidden stuff off screen.  So no,
>you can't double buffer a window by changing pointers.  Some graphics chips let
>you have hardware windows, but not the Amiga's.
>

Um, ok! But, a window still has an associated ViewPort,RastPort,BitMap etc. So
you can still re-connect your own BitMap to the existing one,still have access
to the copper lists through the ViewPort, and make use of RemakeDisplay() to
re-calculate the copper lists. No?
 
 -- 

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#  J.Gold                            |    mapjilg@uk.ac.bath.gdr               #