Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!amdahl!pacbell!att!alberta!myrias!cg
From: cg@myrias.UUCP (Chris Gray)
Newsgroups: comp.sys.amiga
Subject: Re: Ideas for New Custom Chips (a SERIOUS one!)
Message-ID: <617@myrias.UUCP>
Date: 13 Jul 88 19:29:13 GMT
References: <3128@polya.Stanford.EDU> <14146@shemp.CS.UCLA.EDU> <613@myrias.UUCP> <6510@well.UUCP>
Organization: Myrias Research Corporation
Lines: 36

In article <6510@well.UUCP> ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) writes:

   ... stuff about my idea for an area fill graphics mode

>	This sounds a hell of a lot like the new weirdass whiz-bang graphics
>mode on the Apple //-gee-whiz.  After reading about this feature and
>declaring it Pretty Neat Even If Apple Did Think Of It, and thinking about
>how it would be nice if the Amiga had it too, it struck me that we already
>have it.
>
>	It's called HAM mode.
>
>	Granted, it's not as general as the approach outlined above, but you
>still can do "area fills" in HAM using a similar technique by judiciously
>(sp?) selecting pen numbers.

I had thought about that, but couldn't come up with a way that it would work
out. You want to only have to do the actual drawing for the lines. That means
the image would have to be filled with something that propagates the previous
colour. In HAM, you can only propagate the previous colour at the same time
as replacing one of the RGB sets. That means you have to pick one of R, G, or B
to be at only one value throughout your image. If you pick, say, R, then you
fill the image with the 6-bit pattern than means modify R to xxx (you get to
pick what xxx is, but it has to be the same for the whole picture, and it
has to be the same in each of the 16 colour registers you can select directly).

Or do you have something else in mind Leo?

Does anyone out there who has used an Apple II-gs know of any programs or
games that make use of its fill mode (or whatever its called)?

What strikes me as most useful is if the mode could be used in conjunction
with dual playfields. That way, something like Arctic Fox could use the fill
mode to draw its animated view, and use a regular mode for the cockpit stuff.
-- 
Chris Gray		Myrias Research, Edmonton	+1 403 428 1616
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