Alice Averlong🏳️⚧️god. Duke Nukem 1 has so much copy-pasted code.
Like, there's a ton of hint dialog boxes like "You need the key to open this door!" or "you get more points if you catch the balloon"
you'd think they'd just have ShowMessage() and pass it a different string, but nope. it's a different function.
interesting. there's 12 hint-variables which are used to make sure you don't get hinted for something you've used before.
One of them is still maintained, but not used. So there must have been another hintable thing that got dropped
like, it has a function that loops through all 16 color indices and sets them to black. it takes one parameters, which tells it how long to wait between each color is set, so it'll fade slowly to black, instead of being instant.
there's also an identical function that does the same, but sets it to white, instead.
There's a function to draw Dr Proton, a different function to draw Duke Nukem, a function to draw Proton's text, and another function to draw Duke's
the only difference between the "draw proton"/"draw duke" functions is what base address they draw from.
YOU CAN PASS ADDRESSES TO FUNCTIONS, TODD
Exactly identical, except they point to different buffers for different fullscreen images
Nope! it's known, it's just slightly mis-documented and tricky to pull off.
If you press the fire button (not alt!) and release F6 on the main menu, after launching the game with "dn1 asp", you can play the demo level
https://moddingwiki.shikadi.net/wiki/Duke_1_Savegame_Format
0 = not backflipping
1 = left
2 = right
so why in the fuck does the game save your position in the level and the camera position?
You'll always be in the hallway! you can't be anywhere else!
yep. you can have it load you right into a level. you can't save a game there, but you can restore one.
weird.
it doesn't save your keys or if you have the access card, which means you could be trapped after reloading a mid-level save
It saves where the duke is relative to the hallway, even if not his actual position.
I just loaded two different saves of Duke in the first hallway. Didn't press any other buttons... but he appears in different places!
I know this function is a far call (not a "fall car", as my fingers somehow typed it) so I just need to look for JMP 208e:1bb0, right?
> Exception while decompiling 208e:4094: Decompiler process died
this would be easier if Ghidra would STOP FUCKING CRASHING
turns into
EB 09 ; JMP +9
Although it does... okay I think I may have figured out why they did this. One moment while I test.
so, they don't save your position or level state when saving a game, but there IS an exploit: the gun powerup
So you enter level 4, collect the gun powerup, and save. quit and restore your game. You now have the gun powerup, and you can collect it again, getting you to gun level 3. Save and restore again, and now you're max gun level (4).
so you can't use this trick.
now I think they could have solved this in another way: make the save function save the state of duke as he entered the level. They already save that for restoring the player when you die
oh interesting.
the game does reuse a dialog box!
just one of them: The main-hallway hints and Dr. Proton's security-camera taunts? They're literally the same system, with the two sets of text intertwined.
The problem is that they're handled as two 16bit integers, not a single 32bit integer.
So sometimes a function fill be like void foobar(int a, int b, char far * string)
and ghidra will be like "oh it takes 4 parameters!"
honestly real mode x86 is such an abomination of nonsense that we should pretend it doesn't exist.
if only for the minor problem that nearly all PC software and games were written in it for like 12 years
ugh. I don't know what this function even does but I can already tell that the only difference between two adjacent functions is which pointers they use.
TODD, PARAMETERS. PARAMETERS TODD
I'm really doubting the function duplications has anything to do with aggressive compiler optimizations because there's one very small function to determine if something is onscreen or not. It's a couple additions and 4 compares. prime inlining material!
it's not inlined. it's far-called from 148 locations
NULLderef (moved! see profile)
Captain 🚲👣