Cadaver remake

[jotd]

The only level I completed without cheating was level 1 of original levels!!
For all other levels, I had some looks on the walkthrough as this game is damn hard.

The Payoff is damn hard!

@girv: my middleware that I have developped all over the years. There's a version in my unfinished Magic Pockets remake, and source code will be included in the Cadaver remake too (as always, as I have nothing to sell and nothing to hide)

I use to LOVE this game as a kid, I spent hours sitting there trying to complete it, I was so chuffed when i got through to the end.

I spend my now adult life building web app and the occasional games in flash. Would love to build a flash emulation of this, as I have some flash isometric platforms built in the past.

Anyone got the source code or graphical rips, wouldn't have a clue as to where to start decoding/decrypting/extracting from the old original files.

Would really appreciate the help if anyone feels obliged.

ste

[jotd]

I've got the source code of my remake (not completed AT ALL), which could help you a lot.

Cadaver (and its extension) is one of my favourite game ever.
I've played it again one year ago with great pleasure
It's true it's a difficult game, but what a game !
I hope you will finish your remake of the Cadaver game,
so I can try it again
Good luck !

[jotd]

You can download a very early version of Cadaver remake here:

http://pagesperso-orange.fr/jotd/cadaver/index.html

Don't expect much (but you can solve some very basic puzzles from the start), plus you need files from the PC version to make it work.

[alexh]

Very much looking forward to it. Hope you find time to finish this project.

Is your diary supposed to go away after you've looked at it?

[jotd]

Originally Posted by alexh

Very much looking forward to it. Hope you find time to finish this project.

Is your diary supposed to go away after you've looked at it?

nope. But there are a lot of bugs I told ya

I didn't manage to launch your version
I did put the PC files in the data directory, and launched demo.bat
but nothing happened No errors.
What did I wrong ?
Thank you for your help !

[alexh]

Originally Posted by titi4u

I did put the PC files in the data directory, and launched demo.bat but nothing happened No errors. What did I wrong ?

It is not quite clear but you have to put ALL the PC files (including another dir called data) inside the data directory.

[jotd]

Hi all,

The project is not dead. I resumed it recently after 1 year doing other things.

I've made more progress in the data decoding side. I have used WinUAE and tweaked some values in memory in real-time to see what they meant and got some more info (got some nice crashes too )
Disassembling the code is not an option for me. Scares the hell out of me. Now I have enough material to code the 1st level without too many manual additions.

I also added the water monster. Creepy.

I've got a ton of other things to do, like proper object interaction, proper isometric display, etc...

The code has been ported to the DS and it works. But it's slow (I'm sure they changed something in devkitpro as my other stuff is also darn slow now).
Also, text messages are hard to read on a 256x195 screen with rescale!!

[gimbal]

cool I'll be interested to see how you tackled the isometric part - its far from easy to get right, I know that.

[Kroah]

Hello Jotd,

I see you are still working on Cadaver .

Surprisingly, I'm working on a Viewer/Editor. Like you I'm a big BB fan.


I use the Atari ST version of Cadaver because, even if i had to unpack the game first, the Steem debugger allows me to do everything easier than WinUAE/DOS (Dosbox debugger is terrible by the way).

The disks don't have a file system but the bros use a clever resources loader. After extraction, i get almost the same files than the Amiga or PC files. As expected, the data structure are similar (except sound & gfx encoding).

I don't know the packer they use on Atari/Amiga (the algorithm does not seem to be mjm1 nor rnc). I had to rewrite it from the binary. Not that hard, but the main problem will be to repack the data after moding them... I really don't know how to do that. I could patch the game to read the data already unpacked from the level disk, but in this case the disk could contain only 2 or 3 levels max i think.

Originally Posted by jotd

I've got a ton of other things to do, like proper object interaction, proper isometric display, etc...

It seems I don't have isometric alignment problem, could you point me to an example to see if i can reproduce it?
I think the problem you get could come from a weird precomputed "8x8 isometric to cartesian array" they use (it gives the screen dx/dy from a point on a isometric tile). I say "weird" because i don't get the same result if i compute properly the array myself.

I'm actually working on the ACL interpreter which executes the in-game scripts. Scripts are attached to rooms or items and are triggered when a specific event occurs (like "on use"...). This is not really difficult, but there are lots of instructions.

I PM you my source files to check the display algorithm i use.
If you want to execute the program, you can use:
- arrows/PgUp/PgDn to move the objects
- +/- to select the object
- left/right click to change the room, wheel for the level
- Z to hide the hints
- E/R to change the hints
This is not my last version but i haven't changed anything concerning the display.

Keep up the good work!

[Dastardly]

Originally Posted by Kroah

Keep up the good work!

That goes for both of you

[gimbal]

Originally Posted by Kroah

Hello Jotd,

I see you are still working on Cadaver .

Surprisingly, I'm working on a Viewer/Editor. Like you I'm a big BB fan.

Now that is absolutely awesome! With all the information you have between the both of you I'm positive this game is going to be finished. This is especially awesome because JF didn't want to do an editor himself

[jotd]

@Kroah: excellent if you could figure out some ACL stuff. I'll check your editor ASAP.
@gimbal: would be a shame if it was not finished some day!!!

[Kroah]

Originally Posted by gimbal

Now that is absolutely awesome! With all the information you have between the both of you I'm positive this game is going to be finished. This is especially awesome because JF didn't want to do an editor himself

I agree, it's a good thing Jotd and me don't have the same goal, and we are working together to share information. Now we only need to find some free time.

Originally Posted by jotd

@Kroah: excellent if you could figure out some ACL stuff. I'll check your editor ASAP.

ACL interpreter is on its way. There are 93 instructions to analyze. Some are obvious, some are in-game special cases.
Thanks to LEMM for his Amiga longplay, it helps checking some stuffs in late levels because my skill is far from perfect (i think i never reached level 3).

[jotd]

yes the longplay will help! I'm glad that I did not go too far in recoding all scripted info. Actually I think I have coded 2 levers, that's all

There are scripts in objects as well as rooms I think.

I must confess I completed only level 1 by myself, and used the walkthrough from time to time for all other levels!!
The payoff is even harder. I had to use the walkthrough from the start !!! (it was about 17 years ago and I was young).

thinking of it the only BB games I have completed without cheating are Chaos Engine & Gods, even if I know Magic Pockets very well

[BoyC]

Oh wow! There are others!

Cadaver was the very first game I bought on my own money, I've been a big fan of it ever since I saw the walkthrough in an old pc mag
Anyways, I actually started working on the datafiles about 2-3 years back, but due to work stopped after I got the rooms to display.
I'm still interested in the effort though and would love to help you guys out in mapping the data files! You're way ahead of me, so if you have some docs about what's mapped and what's missing that would help a lot.
We could also possibly open a wiki page for it in the xentax game format wiki so it's easier to work on.

[Kroah]

Hi all,

Some news about my Cadaver Viewer.

We have worked hard with Jotd to understand how levels where stored.

You can see on the screenshot:
- a map display (top right)
- a level explorer which shows the rooms and their entities (on the left)
- a script window (at the bottom)



The last feature added is the decoding of the internal interpreter which executes scripts attached to rooms & items. Most of the 93 instructions and 29 type of events are known.

On the picture, you can see the room has 5 attached script:
- 3 scripts are triggered when a zone is collided (yellow rectangle)
- 1 script is triggered when the room timer elapses
- 1 script is triggered when the player enters the room

The script window shows the third zone script when the players touch the bottom right yellow rectangle (the scripts can be viewed but not executed).

Green items have scripts attached to them. They are shown when the item is selected (see the rat at the bottom which has an OnOpen & OnLook event).

The viewer can read the vanilla and The Pay Off levels. Demo levels can't be loaded because they are compressed differently.


Actually, i have lost motivation to work on the viewer for the following reasons:

1) Edited levels can't be saved back because the compression routine is unknown. I have disassembled the decompression code, but there is no way to reverse the algorithm easily. The game can be hacked to load uncompressed levels, but because each level does not share any data with the others, the whole levels are 1,3 MB big (without taking into account the game itself).

2) Each level include 68k assembly code describing some behavior. So the only way to make a full level is to code 68k. Not very smart. Maybe most of the code is the same between the levels, so we could reuse it for the new ones, to be confirmed.

3) Demo levels can't be loaded because the loading and decompression routine are not the same. And if we successfully decode it, the levels might be not compatible (different version of the game engine, data stored differently, ...).

So those 3 points make the work even harder, beside the understanding of the in-game data. And if i have some spare time, i will rather work on disassembling another game.

Originally Posted by BoyC

I'm still interested in the effort though and would love to help you guys out in mapping the data files! You're way ahead of me, so if you have some docs about what's mapped and what's missing that would help a lot.

I will post the viewer with its source soon, maybe it could help you. But i will not have much time to directly help you.

[BoyC]

Originally Posted by Kroah

1) Edited levels can't be saved back because the compression routine is unknown. I have disassembled the decompression code, but there is no way to reverse the algorithm easily. The game can be hacked to load uncompressed levels, but because each level does not share any data with the others, the whole levels are 1,3 MB big (without taking into account the game itself).

3) Demo levels can't be loaded because the loading and decompression routine are not the same. And if we successfully decode it, the levels might be not compatible (different version of the game engine, data stored differently, ...).

The pc version could be a solution to these problems. During my old research I found out that there were at least two versions of the game released, one with compressed and one with uncompressed data files. The game still supports the uncompressed level format, thats one way of how I messed around with it by editing into the files. It would be a nice goal to try and have the demo levels on the pc version for example.