Path: utzoo!attcan!uunet!samsung!uakari.primate.wisc.edu!sdd.hp.com!ucsd!helios.ee.lbl.gov!nosc!crash!jcs
From: jcs@crash.cts.com (John Schultz)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Using CPU instead of Blitter for speed
Message-ID: <3037@crash.cts.com>
Date: 7 Jun 90 18:32:42 GMT
References: <30974@ut-emx.UUCP> <3022@crash.cts.com> <13493@etana.tut.fi>
Distribution: comp
Organization: Crash TimeSharing, El Cajon, CA
Lines: 31
X-Local-Date: 7 Jun 90 11:32:42 PDT

In article <13493@etana.tut.fi> kp74615@kaakkuri.tut.fi (Karri Tapani Palovuori) writes:
>In article <3022@crash.cts.com> jcs@crash.cts.com (John Schultz) writes:
>
>>then blit the mask to each bitplane. If you want polygons that don't have
>>broken or coarse edges, you must re-outline the mask with lines using 
>>the blitter.  
>
>This is not necessary. You can draw the leftmost lines one bit too left and
>use exclusive fill mode.

  I tried exclusive fill, inverting the mask, etc. This did produce sharper
polygons, *but* they still fell apart when horizontally thin.

>Further, with blitter optimized code you can draw polygons of any shape,
>including holes in them. This is a great advantage in some situations.

  That's true, as well as concave polygons.

>I agree that the 68000 is sometimes faster than the blitter. But it really
>depends on the average polygon size and shape.
>
>But the speedup gained by faster processors is one of the strongest points
>supporting CPU-drawing. I think.
  
  You think right. I just read on comp.sys.amiga of a TI TIGA board
for the A3000. A 34010 will put to rest any dialogue disputing processor/
blitter speed. If it's a 34020 (250 megs/sec transfer), the Amiga will
be a most formidable low cost graphics speed demon.


  John