Path: utzoo!attcan!uunet!cadnetix.COM!cadnetix!childs
From: childs@cadnetix.COM (David Childs)
Newsgroups: comp.sys.amiga.tech
Subject: Re: WaitTOF in interlace mode
Message-ID: <3379@cadnetix.COM>
Date: 21 Jul 88 16:32:41 GMT
References: <4860@killer.DALLAS.TX.US> <2596@amiga.UUCP>
Sender: news@cadnetix.COM
Reply-To: childs@cadnetix.COM (David Childs)
Organization: Cadnetix Corp.,  Boulder, CO
Lines: 36

In article <2596@amiga.UUCP> jimm@cloyd.UUCP (Jim Mackraz) writes:
<In article <4860@killer.DALLAS.TX.US> ltf@killer.DALLAS.TX.US (Lance Franklin) writes:
<)  Right now, I open
<)a CUSTOMBITMAP window with two planes on the WorkBench, then allocate a
<)bitmap with a single plane with it's address replicated in both plane pointers
<)in the RastPort.Bitmap structure.  This allows me to have four color gadgets
<)in the frame, but faster blits (thru a second RastPort structure pointing to
<)the same single plane).                ^^^^^^^^^^^^^^^
<
<Nice idea, I think.  Actually, no.
<
<Don't forget: the actual number of bitplanes visible is determined by
<the screen.  Superbitmaps, etc. are just metaphors, and not always 
<particularly fast metaphors.
<
<Your trick would probably do everything twice, for both bitplanes,
<whether the bitplanes were at the same address or not.  You need to lie
<about either the BitMap.Depth or the RastPort.mask to get rendering
<to only do one plane.

I believe Lance was saying he uses a different RastPort structure with a depth
of ONE point to the same single plane the other RastPort points to twice, and
then uses the second different RastPort to do the blit.  If I'm wrong please
tell me.  Why would it render everything twice if he used his second Rastport?
I understand that the screen has 2 bitplanes, but if the Rastport has only one
where would the second blit go?

<)Thanks.....Lance
<	jimm

David

   David Childs               Internet: childs@cadnetix.COM
   Cadnetix Corp              UUCP: cadnetix!childs
   5775 Flatiron Pkwy               {uunet,boulder,nbires}!cadnetix!childs
   Boulder, CO 80301