Path: utzoo!utgpu!water!watmath!clyde!rutgers!ll-xn!mit-eddie!uw-beaver!ssc-vax!coy
From: coy@ssc-vax.UUCP (Stephen B Coy)
Newsgroups: comp.sys.amiga
Subject: rp.Mask and fast graphics
Keywords: Mask
Message-ID: <1593@ssc-vax.UUCP>
Date: 15 Dec 87 20:40:12 GMT
Organization: Boeing Aerospace Corp., Seattle WA
Lines: 24


	...what's all this talk I hear about lion eaters?

Hi,
    I've got a question about how to get the most speed out of the
Amiga's drawing routines.  In the RastPort structure there is a byte
called Mask which masks off which bitplanes are "drawable" and which
aren't.  What I'd like to know is how deep into the various drawing
routines is this looked at.  ie on a 5-bit deep screen 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?  What I'm hoping to hear is that the blitter is only set up
once because only one plane can be drawn to.  Is this true?  I'd be
quite disappointed if I found that the blitter is set up for each
bit plane and then the mask byte is looked at.  Also, how about
WritePixel?  I know the savings on this won't be much but at times
just about anything is useful.

Thanks in advance for any useful insights.

Stephen Coy
uw-beaver!ssc-vax!coy

		"Only the mediocre are always at their best."