(2024-01-29) Elite in AWK: the beginning
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As I said in the previous post, I wasn't joking. Elite, even in its text
version, is an interesting case of how a seemlingly infinite universe can be 
created with pretty limited resources involved. And when Ian Bell, one of 
the original Elite creators, released the universe generation and trading 
algorithms in a form of Text Elite in 1999 (with some fixes going on until 
2015), I knew it was just a matter of time for me to try and port it myself 
when I discovered it.

Of course, what I had to deal with was monstrous. While Bell was a genius who
did wonders in 6502 assembly in the original Elite series, it looks like he 
didn't master C at all, even calling it "a brain-dead language" in the 
original source code file. Maybe, that's for the best, otherwise I'd have to 
deal with pointer arithmetic when porting it, to the addition of everything 
else. By the way, I have nothing against Bell himself. But I had to read the 
code of _three_ other ports of Text Elite to understand better what whas 
going on there: in JS, in Python and in Erlang (which I can barely read but 
hey, it's much more readable than e.g. Rust). And as for these ports, I do 
have questions to their authors.

Let's take a look at this tiny code fragment from the original TXTELITE.C:

int myrand(void)
{ int r;
  if(nativerand) r=rand();
  else
  { // As supplied by D McDonnell from SAS Insititute C
    r = (((((((((((lastrand << 3) - lastrand) << 3)
        + lastrand) << 1) + lastrand) << 4)
        - lastrand) << 1) - lastrand) + 0xe60)
        & 0x7fffffff;
    lastrand = r - 1; 
  }
  return(r);
}

Screwed-up indentation and typos ("Insititute", lol) are all over the code,
so I got used to it when porting, but the middle expression that calculates 
r... I really had to spend more time than I should in order to understand 
that this abomination could just be replaced with:

r = (lastrand * 3677 + 3680) % 2147483648

Again, Bell was porting his algos from 6502 "as is" without even trying to
optimize anything (as he didn't know C well enough), no questions to him. 
But... all three ports I looked at, written by third-party people, had the 
same original formula with a ton of shifts and parens intact. This means the 
porters didn't even try to understand what it was actually doing. And this 
was the point I understood that my own port had to be completed, it had to 
be done strictly in POSIX AWK with no external dependencies and it had to 
become better than all of those.

When done with the basic porting (which was quite non-trivial as POSIX AWK
doesn't support hex literals in strings or in code, as well as bitwise 
operations), I quickly understood how boring the original TE 1.5 was. Come 
on, it had "cash", "hold" and "sneak" commands, as well as free 
intergalactic jumps! It was a fair trade engine recreation, but far from... 
well... a game. It was too easy to perform unfair moves there, and it didn't 
even have any reward system besides bare cash. So I decided to move on and 
create my own game-like experience on top of the original codebase, and 
first things I did was to make hyperjumps non-free (5000 credits like in the 
original Elites), to limit the "hold" command to one-time 35t upgrade for 
400 credits (like in the original Elites) and to move "cash" and "sneak" 
commands to a special cheat mode. A bit later, I introduced savestates so 
the cheat mode (along with those commands) became fully unnecessary and was 
removed. I also ported galaxy names from the Archimedes version of Elite. 
But then, I had two more things to do to consider my part done.

The first and, I guess, most important thing is the statistics and ranking
system. The original Elite versions had ranks based on the number of kills, 
which doesn't make any sense in this version that has no combat whatsoever. 
One of the modern Elite incarnations, Elite Dangerous, has its own "Trade" 
and "Explorer" ranking scales, but the point system is very different from 
the classics, so I just took the trade rank names from there. But the method 
to calculate the rank still was on me. And I still am not sure whether the 
formula I settled on is viable, but as of today, it's like this: the game 
keeps track of *all* your expenses, then calculates the overall profit 
margin as (cash - 100CR) / expenses, then takes floor(log2) of it and 
assigns the rank based on this number. So, e.g. to get to the Elite rank, 
you must have made 128 times more money than you spent. I repeat, I don't 
know whether this is possible at all yet, so the formula (or at least the 
logarithm base) might change in the future.

The second thing is the ship upgrade system, and this is the most recent
change to the game to this day. Instead of the "hold" command (one-time 
upgrade to 35t for 400 CR in my port or arbitrarily changing the cargo in 
the original TE), the "upgrade" (or "up") command was introduced, that would 
allow you to buy different ships (that, in this game, still only vary by 
their cargo hold space) for different prices. Here, the ship names, specs 
and prices were taken from Oolite:

- Cobra Mk3 Extended (35t, 400 CR) - like in the originals
- Python (100t, 200000 CR)
- Boa (125t, 450000 CR)
- Boa 2 (175t, 495000 CR)
- Anaconda (750t, 650000 CR)

The implementation of this feature was quite straightforward (while the
"hold" command seemed like a hack anyway) but again, I'm still not sure if 
all of them are even necessary. Still, attempting to reach the highest 
upgrade tier can be considered one of the in-game goals.

Speaking of goals, what about finding the legendary Raxxla? Of course, the
planet with such a name doesn't exist in the classic Elite universe, but if 
we consider "x" as a wildcard character, there exists precisely one planet 
that fits this template. If you find it, my port will give you a hint about 
that. It might seem totally unnecessary but brings an additional element of 
fun lacking in the original Bell's version.

That being said, I invite you to play my port, awlite, and test it out:

git clone git://git.luxferre.top/awlite.git

At the time of this post, its major version is v1.8 (the numbering started
from the direct port being v1.5) and I doubt the savefile format will 
further change much, but the code is readable and the README is a must-read 
if you seriously want to play it. I hope you enjoy.

By the way, please write to me on Matrix if you have any suggestions or
feedback about the game or any other project of mine: 
@luxferre:hackliberty.org

--- Luxferre ---