-----Original Message-----
From: Erik Mooney <emooney@xxxxxxxxxxxxxxxx>
To: stella@xxxxxxxxxxx <stella@xxxxxxxxxxx>
Date: Sunday, January 18, 1998 10:53 AM
Subject: Re: [stella] Screen shots
>Looking at the code, this seems more complex than I was expecting :) In
>the rendering engine, you use gs:di as the segment:offset for video memory,
>right? I'm hoping to leave most of the object-handling code alone and only
>change anything that says mov gs:[di]. In mode X, though, you can't do
>word or dword stores to video memory - supposedly, the bank select register
>can only handle one input byte at a time, so you can only mov gs:[di],byte.
Sorry about the complexity! Was all in the interest of speed. But
underestimating the complexity of a project seems to be a fairly common
occurence in this business :)
Interesting info about byte stores to video mem, I was wondering about that.
>Page flipping might actually be possible... if we get the rendering portion
>into mode X, it's a small step to make the starting offset for the renderer
>alternate between 0 and 32k on alternate frames. There wouldn't be enough
>video memory to page-flip in a 480-line interlaced mode (320x480x2 > 256k),
>but then you probably wouldn't want to anyway.
If it's not too hard to do then cool!
One thing I've been thinking about is making sure that mode 13 can still be
an option. Would it be possible for you to set up a parameter that's
hard-coded for now but which could easily be turned into a command line
option? I was also thinking you might want to have you're own version of
TIALineTo, or else we split out the smallest portion needed, maybe call it
TIARenderLine or something like that and we select it with something like
CALL [TIAREGVECTOR + EBX*2] :)
and maybe the same thing with the graphics setup code. What do you think?
John
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