Path: utzoo!utgpu!water!watmath!clyde!rutgers!ucla-cs!zen!ucbvax!hoser.berkeley.edu!bryce
From: bryce@hoser.berkeley.edu (Bryce Nesbitt)
Newsgroups: comp.sys.amiga
Subject: Re: rp.Mask and fast graphics
Keywords: rp_Mask
Message-ID: <22238@ucbvax.BERKELEY.EDU>
Date: 19 Dec 87 06:52:36 GMT
References: <1593@ssc-vax.UUCP>
Sender: usenet@ucbvax.BERKELEY.EDU
Reply-To: bryce@hoser.berkeley.edu (Bryce Nesbitt)
Organization: The Logic Foundation
Lines: 35

In article <1593@ssc-vax.UUCP> coy@ssc-vax.UUCP (Stephen B Coy) writes: >
>
>    I've got a question about how to get the most speed out of the
>Amiga's drawing routines. 
>[If I want to] do a RectFill in color 4 and I know that the screen is blank
>(all 0) do I gain much by setting rp.Mask = 0x04 before making the RectFill
>call?

Yes, you gain.  I got some respectible speed increases when playing with
this a while back.  Problem is I ran into a bug**; if you set rp_Mask
of an Intuition window the graphics routines respect this for *all*
operations.  Great, but what about depth gadgets?  You guessed it,
only the selected planes get moved.

** Definition "Bug": something that when I asked Dale Luck about it, he
said "Yeah, that's a bug [...] we'd like to fix that some day."


>Thanks in advance for any useful insights.

You can also get some speed increase in many real applications with
multiple viewports.  In the stripes of screen were you need less colors,
use less bitplanes.

The Atari group is all fired up over the "Colorburst" kludge.  With the
copper you could play the same color-pallete games, but still keep
the CPU speed intact.
I'd like to see a bitplane minimizer that uses the copper to switch
some pallete colors so the picture is not affected at all by the dropped
planes.

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