Doom Level Hacking Tutorial

[ovalbugmann]

Still working on other tutorials, will post them when they are done.

 

Yes!, Please do post any other tutorials you have or are in the process of making for working with the Jaguar Doom wad files, I could use the help.

[neo_rg]

They are being done, along with some other Doom related stuff, it's not forgotten. I just can't multitask

like I used too. It's one of the downfalls of working full time, and having a 2nd part time one. What free

time I do get I spend sleeping... should drink more Red Bull!!

[walter_J64bit]

Good luck!

[Tyrant]

Just read through all of these, they're really excellent.

 

You certainly seem to have the map format sorted. Have you done much digging with the other game assets, sprites, animation data, sound, etc?

 

Also have you worked out what kind of compression they're using?

[madmax2069]

Very interesting.

 

I do have a few games (including doom) but my Jag no longer works (and even worse i can not find it to try and to fix it).

[neo_rg]

Just read through all of these, they're really excellent.

 

You certainly seem to have the map format sorted. Have you done much digging with the other game assets, sprites, animation data, sound, etc?

 

Also have you worked out what kind of compression they're using?

 

Thanks for that 8-)

 

I've managed to work out all the wad assets, but will be ignoring the midi as it too much of a cludge, when a remake comes out it won't be using that.

Some stuff is hard coded into the source, like sprite animations, but they can be changed if you want to hack with the source. The compression used in

Jaguar Doom wad is a version of LZSS compression, the depack rout is in the source. There is no 100% compatible pack rout atm so, as before it won't

be used in a remake. Best thing is to get rid of the rubbish and use better routs for packing and different methods for music replay.

 

The more people that have a go at hacking levels, the more they will learn about what the Jaguar can and can't do with levels. ID simplified most of

the Doom maps so they would work on the Jag, if they had to do it then they knew the engine wasn't up to the task.

[Tyrant]

I've managed to work out all the wad assets, but will be ignoring the midi as it too much of a cludge, when a remake comes out it won't be using that.

Have you had a read of the fulsyn (sound and music) docs? That is one massive kludge, but does use midi data, heavily pre-processed. It's possible they were just using that (I believe iD never wrote their own sound code, and regretted it afterwards). I'll attach the pdf to this post. Edit: oops, max size 2mb, shout if you need it

 

Some stuff is hard coded into the source, like sprite animations, but they can be changed if you want to hack with the source.

I believe sprite animations always were hard coded, now I think about it. On the PC one would use a tool called DeHacked, which edited all the vast tables of data in the back of the doom executable.

 

The compression used in Jaguar Doom wad is a version of LZSS compression, the depack rout is in the source. There is no 100% compatible pack rout atm so, as before it won't be used in a remake.

Compression is a Good Thing^tm. It shouldn't be hard to write a suitable packer, or else replace the unpack rout with a new one.

 

The more people that have a go at hacking levels, the more they will learn about what the Jaguar can and can't do with levels. ID simplified most of the Doom maps so they would work on the Jag, if they had to do it then they knew the engine wasn't up to the task.

It was probably not a case of incapable, but quicker/cheaper. They started off porting it to the 68k, then moving one rout at a time onto the riscs until it ran fast enough. They could have got a lot more out of the Jag if they'd continued that process longer. I suspect they reached a point where they could say "Look, we've got it 90% working but this stuff will take another 2 months" and decided to just cut stuff rather than delay the project for extra polish.

Edited August 3, 2010 by Tyrant

[JagChris]

Its amazing how well JagDoom runs considering how much of the 68k it uses.

[madmax2069]

Its amazing how well JagDoom runs considering how much of the 68k it uses.

 

it probably used more then the 68k though. at least not in the same since as running Doom on a 68k Mac (a Performa 475 as a example, which i do have)

Edited August 6, 2010 by madmax2069

[Tyrant]

As a general rule the 68k is a fine chip for running the kind of routines that only happen a few times per frame, the game logic, AI, stuff like that. Things which do batch processes over every pixel, like rendering walls or effects, should naturally be done on the GPU.

[busterm]

So is anyone doing any hacking based off this tutorial.

 

I've been getting accustomed to the Doom builder the past week myself but have yet to inject any of them into the Jag Doom rom.

[JagChris]

I havent actually tried this but just wanted to make sure is this tutorial complete? Is there any other information I need to know that is not included in here? Someone was suggesting maybe some needed big/little endian info was accidentally left out? But they were not sure as its been a long time since they messed with any of this. I just wanted to double check.

[neo_rg]

For hacking levels into doom, yes it's complete. it's just a quick and cheesy way of doing it.

If you need more information about stuff other than this then the answer is no.

[JagChris]

For hacking levels into doom, yes it's complete. it's just a quick and cheesy way of doing it.

If you need more information about stuff other than this then the answer is no.

 

ok thank you. I think I am going to try to get my ex roommate to make a program to automate this process. So I just wanted to make sure this was complete and that it was all the information necessary to go about make a total conversion.

[JagChris]

OK I think I understand now. This does not have the information needed to do a total conversion?

[Jag_Slave]

The tools nor anything else beyond a hack for Jag-Doom will ever be released or exist. Because screw it, I said so thats why.

Throw Eerievale in there with it, along with 100's of Gorfs titles, Phear, and anything else. If I had all of the tools, and titles I wouldnt release anything either. Ever. Forever. And Ever. Never. Clever. And Trevor <3 <3

[sh3-rg]

OK I think I understand now. This does not have the information needed to do a total conversion?

 

Maybe you can run a competition to see if anyone can answer this for you?

 

All the Doom hacking guide will allow you to do is hack Jaguar Doom with your own assets and produce similar results to the Doom II youtube videos. You can design your own levels or modify existing ones, but so far I've not seen any sign of anyone doing that other than Neo.

 

Matthias has probably looked more closely at Jaguar Doom than anyone, his 'Doom Lite' stuff was pretty impressive. If GGN were to pick his brains a little I expect he'd have enough to go on to continue working on his tools, but interest in that was lost a long time ago and he'd need some serious encouragement to devote what little free time he has to doing so.

 

Not sure what Jag_Slave's point was exactly... I've read it a number of times but can't get to the bottom of it I think I need to find out who this Trevor person is and subject him to 4 hours straight playing *** ******.

[+CyranoJ]

To be fair, I can't say anything to ggn for wanting to work on the Falcon instead of the Jaguar. It is a mighty tempting target platform, without all the bullshit 'politics'.

[TXG/MNX]

Does anyone know how a wad is loaded on the jag ?

 

I suppose the MAPxx that you're gonna play will be copied and decompressed to RAM and run from there or does it work different ?

 

When RAM is used ,does someone know which start address the mapxx is copied to and how big this reserved RAM is ?

[justclaws]

I am several years late but well done and I will enjoy reading all this later! I also would like to try the ROM back from ejagfest but did not find these yet. Maybe at EJF18.