A patch for Ultimate or Final, DOOM

[Vegeta]

How hard should be to make a patch for doom.exe and doom.wad that includes a new boss at the end of the episode 4 without replacing any monster? In a source port this should be easy, but if you want to keep the doom.exe intact, with the exception of a new creature added, with its own sprites. A dehacked patch should suffice I think, but even so, is it posible to add (usable) extra sprites to an iwad?
And what if you want to add a new creature in DOOM 2 without replacing any thing. I know the magic of coding, but I don't know how hard should be that to implement.

[BlackDeath]

Hard

[Xenophon]

Not very difficult. Use the unused "dead lost soul" and give the boss's sprites the same four letter identity as any of the existing sprites (FATBxxxx for example). Use the frames for the SS soldier, but with different codepointers and graphics. (AFAIK they exist in Ultimate Doom, but aren't used because SS soldiers can't be placed down and the frames aren't in the wad file) Creating a unique attack for the boss is a different matter.

[NiGHTMARE]

Tell people to use doom2.exe rather than doom.exe (simply rename it doom.exe), and then you'll have all the extra D2 sprite numbers and frames to play around with.

Of course, the vast majority of people will be using a source port anyway ;).

[deathbringer]

If you want to add new THINGS without replacing anything, and not using a port, you'll need to edit the code of doom, but then you'll be creating a port, albiet a minorly-changed one. If you want to add a new boss, a half-assed way to do it is give some object all the frames of an existing boss, but give it different attack pointers, or make it invisible, a stealth spider mastermind that has 8000 healh points and shoots rapid fire caco fireballs shouldnt be very hard. You'll just have to remember what obscure scenery item you used, and remove that from your other maps

[Grazza]

NiGHTMARE said:

Tell people to use doom2.exe rather than doom.exe (simply rename it doom.exe)

Doom2.exe 1.9 is identical to Doom.exe 1.9 (i.e. the exe for the last 3-episode version before Ultimate Doom), so this has the effect of making episode 4 inaccessible, amongst other things.

[Nick Perrin]

USE EDGE OR ZDOOM FOOL

[NiGHTMARE]

Grazza said:

Doom2.exe 1.9 is identical to Doom.exe 1.9 (i.e. the exe for the last 3-episode version before Ultimate Doom), so this has the effect of making episode 4 inaccessible, amongst other things.

Okay, so use the .exe that comes with Final Doom then, I'm pretty sure that has everything. I also don't think Doom.exe v1.9 and Doom2.exe v1.9 are identical anyway; why would the former have the latter's sprite frames, level names, etc?

[Graf Zahl]

NiGHTMARE said:

Okay, so use the .exe that comes with Final Doom then, I'm pretty sure that has everything. I also don't think Doom.exe v1.9 and Doom2.exe v1.9 are identical anyway; why would the former have the latter's sprite frames, level names, etc?

Because it is all in the code. Taking it out is more work than leaving it in. You can indeed put the sprites for Doom2's decorations in a PWAD, load it with Doom1 and have them displayed properly.

And the Final Doom Exe does indeed contain everything: All Doom 1 specific stuff, all Doom 2 specific stuff plus all the FD additions. I have played all Doom games with it for some time because back then I had no access to the game updates.