Re: A86: SCrolling
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Re: A86: SCrolling
At 20:22 1998-10-27 -0600, you wrote:
>
>Ah, that's neat to know. Redrawing that one pixel edge is really a pain.
>It's a map lookup, putsprite and findpixel all rolled into one nice, neat
>mess of code. I can't wait to see your new engine.
>
>Is anyone making or thinking about making a 4 way scroller, like Mario 3 or
>Commander Keen? A game like that would really be awsome.
The new engine IS a 4 way scoller. It works like this: you set up
a virtual screen, which can be up to about 10k. For instance,
a 320x200 virtual screen (320*200/8=8000). Then you put all your
sprites and stuff on the virtual screen, and update the
screen with a call to UpdateScreen. The variables XScr and YScr
tells UpdateScreen what part of the virutal screen is to be shown.
Also, there shouldn't be very much flicker, because every call
to UpdateScreen flips between using the videomemory at $FC00
and $F800 (yes, the stack has been moved).
I'm thinking of a grayscale version of it, but then there will
be little memory for the virtual screen. It would work if
you could free another RAM (page 7 by moving the end of VAT to
the end of page 6 temporary) and put it at $4000-> whenever
updating it.
--
Real name: Jimmy Mårdell
Email: mailto:yarin@acc.umu.se
Homepage: http://www.acc.umu.se/~yarin/
Icarus Productions homepage: http://icarus.ganymed.org/
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