Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!ucsd!ames!ncar!boulder!tramp!hassell
From: hassell@tramp.Colorado.EDU (Christopher Hassell)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Double-Buffering in a window
Summary: Ahh..... what little we say before we know
Message-ID: <15547@boulder.Colorado.EDU>
Date: 11 Jan 90 20:16:01 GMT
References: <897@mindlink.UUCP> <1990Jan10.134148.21435@gdt.bath.ac.uk>
Sender: news@boulder.Colorado.EDU
Reply-To: hassell@tramp.Colorado.EDU (Christopher Hassell)
Organization: (Let's see, I'm positive <clang> .. I've <rustle> got ... )
Lines: 56

<1990Jan10.134148.21435@gdt.bath.ac.uk> mapjilg@gdr.bath.ac.uk (J I L Gold) :
# In article <897@mindlink.UUCP> a464@mindlink.UUCP (Bruce Dawson) writes:
# >
# >     All of the windows in a screen share the same bitmap (at least for their
# >visible portions, which is what you're interested in).  So, if you want to
#>double buffer one window, you've got to double buffer all of them.  The entire
#>screen gets flipped all at once.  So, unless you first copy the contents of 
	the
#>entire screen to the hidden buffer, the other windows are going to flashing on
# >and off as you flip bitmaps.
# >
# 
# However you do have access to the layers through CopySBitMap() and SyncSBitMap()
# which I'm reliably informed do the job nicely!
# -- 
# J.Gold | mapjilg@uk.ac.bath.gdr
# 

Those ARE valid software techniques.  I'm not giving any advice here... just
dreaming a bit:

But ..... it would be nice 
	A: if the copper could blit stuff around CONSTANTLY (as in every scan)			from a different and wierd portion of separate memory
	B: if there was a simple option in the copper which allowed you to
		SIMPLY CHANGE THE SCAN-ADDRESS WITHIN A SCAN-LINE AND WORSE.

If/When the amiga basically cannot keep its innards together and it explodes
into a multiprocessing machine (which should be alot more blase' to make in la
future).... wouldn't it be nice to LITERALLY have "windows" into memory....
windows into displays that are configured who-knows-where in that Meg or two
your A500 enjoys?

So much for problems with multitasking and display-haggling... they wouldn't
even need to be resolved by a window manager... below a certain level... they,
screen conflicts, would simply never occur because the screen only chose to
listen to specific parts of any program's actual workings.

I like the idea personally... if I get enough money.. I might even try to hack
something like that together on a little dead Apple //+ (where everything is
socketed). 

It would be mucho nicer on the amiga, of course.

Your arguments are valid for what should be done.  I believe that there are
"windowing" graphics-management chips out there which do exactly what I said...
but they are definately high-end and somewhat restrictive.

Latuh.
# -- 
# #------------------------------------------------------------------------------#
# # Paranoia is thinking that if something CAN'T go wrong it will still go wrong.#
# #------------------------------------------------------------------------------#
# #  J.Gold                            |    mapjilg@uk.ac.bath.gdr               #


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