Path: utzoo!utgpu!water!watmath!clyde!rutgers!psuvax1!vu-vlsi!hvrunix!ahinds
From: ahinds@hvrunix.UUCP (Alexander Hinds)
Newsgroups: comp.sys.amiga
Subject: Re: BitMaps
Summary: I already tried using Intuition
Keywords: Just how are they represented in memory?
Message-ID: <397@hvrunix.UUCP>
Date: 30 Jan 88 18:26:24 GMT
References: <396@hvrunix.UUCP> <40367@sun.uucp>
Organization: Haverford College, Haverford, PA
Lines: 25

In article <40367@sun.uucp>, cmcmanis%pepper@Sun.COM (Chuck McManis) writes:
> In article <396@hvrunix.UUCP> ahinds@hvrunix.UUCP (Alexander Hinds) writes:
> >	I've been trying to read the bit values of a BitMap in a particular
> >plane and store them in an array.  I've looked throught the RKM's and haven't
> >found anything too helpful.  Can anybody tell me how the bits are stored and
> >how one can read them out of memory?
> 
> Bitmaps, being bit plane oriented, are a bit different on the Amiga :-). But
> they are still pretty easy to get to. The simplest way is to initialize a
> RastPort to point to a particular BitMap and use ReadPixel(). But since you
> asked about the organization, here goes ..

	What I was trying to do was to grab the screen via Gfx->ActiView and
store the screen data.  I tried to use intuition by initializing a RastPort
and setting the BitMap pointer to the one in ActiView->ViewPort->RasInfo->BitMapThen, I tried to use ReadPixel.  And, of course, during this, I surrounded this
block of code with a Forbid() Permit().  However, the machine crashed on me
every time, most of the time with an Adrress Out of Range or an Opcode 1111
error.  I couldn't figure out why, so I stopped trying that method.  Was I
doing something wrong, or overlooking something?  Anyway, thanks for your help.
I hope I can get it to work this time!

						Alexander Hinds

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