Re: [stella] GTA 2600: Started!

Subject: Re: [stella] GTA 2600: Started!
From: "Mark Graybill" <saundby@xxxxxxxxxxxx>
Date: Wed, 30 Jul 2003 16:03:35 -0700
From: "Manuel Polik" <cybergoth@xxxxxxxx>
> Cool! I mean -> "GTA Vice Dungeon"! Really cool!
That is really cool.

> > Have you planned the dungeons and objects generation
> > stuff already?
> Unfortunately no. I'm currently reverse-engineering the
> 8-Bit version (still any help appreciated!) and hope to
> get some ideas from that. Main Problem is that it
> completely generates the dungeons out of seed values,
> relying on the giant amount of RAM of the 8-Bits.
I did some reverse engineering on the Apshai series and Fargoal way back
when. You're right about them taking advantage of all that RAM. Fargoal gets
by with less data as I recall, but Apshai would store some fairly large data

The old "Devil's Dungeon" game from the book Stimulating Simulations had a
very tight structure for generated levels. For the game I wrote ("RatQuest")
I started with that structure then moved to a matrix structure that allowed
me to modify the dungeon size (and memory usage) easily. In Devil's Dungeon
format, a 16-room level would occupy about 80 bytes, in my matrix format it
was about 104 bytes, since I added the ability to have named monsters and a
named item in the room (taking advantage of the masses of RAM available on
the unexpanded Vic-20. ;) I also changed it so that it was possible to trade
experience for stats in rooms other than room 1 and room 1 acted just like
any other room. The altar became just another flag, rather than a fixed
location on the map.

The addition of named items expanded the size of the character data
structure, too. It had started out at 8 bytes for stats, experience, and
gold (two bytes per value), and I added another 16 bytes for a character
name, and then the items added another 8 bytes. Basically there were 255
named items in the game, and the character could have 8 of them. Each of the
8 slots was associated with a type of thing, they could only have one type
of thing (helm, weapon, shield, etc.) at at time, and the number pointed to
a data structure where all the info (name, stats) could be looked up (either
in RAM or ROM depending on the platform.) The monster type was an index for
lookup of name and description as well. And each level had an additional
generated byte for "atmosphere", which pointed to a structure of environment
descriptions. On the small versions these were short phrases used in room
titles. In the larger versions they were longer and more sophisticated.

I'm probably not telling you anything you haven't already thought through,

But I'm really looking forward to firing up GTA Vice Dungeon on my system,
so I thought I'd jump in...

-Mark G.

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