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Path: utzoo!utgpu!water!watmath!clyde!rutgers!uwvax!puff!avery
From: avery@puff.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: SUPER_BITMAP Windows
Message-ID: <663@puff.WISC.EDU>
Date: Sat, 18-Apr-87 01:21:35 EST
Article-I.D.: puff.663
Posted: Sat Apr 18 01:21:35 1987
Date-Received: Sat, 18-Apr-87 19:01:21 EST
References: <1013@crash.CTS.COM>
Organization: U of Wisconsin CS Dept
Lines: 29

In article <1013@crash.CTS.COM>, billk@pnet01.CTS.COM (Bill Kelly) writes:
> SUPER_BITMAP, GIMMEZEROZERO window (in a customscreen) so that I could draw
> my text into it's own bitmap without disturbing anybody.  The problem is that
> I am drawing into the bitmap, but the bitmap isn't being displayed on the
> screen.  Is there any trick to doing this?  The window is a BACKDROP,
> BORDERLESS, GIMMEZEROZERO, SUPER_BITMAP window in a screen with a depth of
> one.  My words draw into the bitplane in the BitMap of my window (which is the
> only one open on the screen) but nothing (as I said) is being displayed on the
> screen.
>
What you want to do is have the Screen and Window share the same bitmap. I
have usually done this by letting Intuition allocate the bitmap during the
OpenScreen() call, and then linking it into my NewWindow structure before
doing my OpenWindow. This should give you an idea of how to do it:
NewWindow.Flags = BACKDROP | BORDERLESS | GIMMEZEROZERO | SUPER_BITMAP;
NewWindow.Type = CUSTOMSCREEN;
NewWindow.Screen = myscreen;
NewWindow.BitMap = myscreen->ViewPort.RasInfo->BitMap;

I have used this with success. You can also fill NewWindow.BitMap with
&(myscreen->BitMap), but this is only a copy, and since you're passing
a pointer to it, I think the above is right. Someone at Commodore is
invited to correct me if I'm wrong, but I think you're safe having them
share that BitMap structure. Now your window, screen, viewport, layer, and
rastport are all using the same BitMap structure, so, hopefully, there's no
memory waste and any changes in the structure will affect all of the above.

Aaron Avery ({caip,seismo,allegra,harvard,ihnp4}!uwvax!puff!avery)
	    (avery@puff.wisc.edu)