Modding for Mac?

Wrong.

What if each map loads different tileset?
What if each map has a different name?
What if each map has a different npc sprite sheet?
What if the starting health is different?
What if the weapons are hacked?
What if the start map is changed?
What if the start event number is changed?
What if the start position is changed?
What if the start health is changed?

That are things nearly all mods have changed. Especially the different tilesets or npc sprite sheets. So you need to change the hardcode. :/

We were talking about changing maps, not anything else. That only needs map names and tilesets. I include the npcs loaded as a tileset.

 

I think C-style, don't know the difference.
So what about a messager? (ICQ, AIM, MSN)

Actually according to my notes it's like this, alltough the format is the same:

The map information starts at 0x00937B0
Each map-entry is totally 0xC7 in length.

0x00 - Tileset
0x20 - Filename
0x40 - Background Type
0x44 - Background Name
0x64 - NPC Sprite-Sheet 1
0x84 - NPC Sprite-Sheet 2
0xA4 - Major Boss
0xA5 - Mapname

There are 0x5F (95) maps. In there original exe there is space for 0x80 (128) maps.

Major Boss list:
0x00 - No Major Boss
0x01 - Omega
0x02 - Balfrog
0x03 - Monster X
0x04 - The Core
0x05 - Iron Head
0x06 - Dragon Sisters
0x07 - Undead Core
0x08 - Heavy Press
0x09 - Ballos

 

I think C-style, don't know the difference.
So what about a messager? (ICQ, AIM, MSN)

Yeah, they are C-style – a Pascal-style string stores the length of the string in the first byte. (I checked one string.) It's actually easier that they're C-style.

As for a messager... I don't have one, although I have recently been debating whether to get one. I do have Google, which has a chat, but I've never used it.

Edit: The offset you gave for windows is 0x10 places earlier than the one you gave for Mac, in terms of the actual data stored there. Or so it seems, anyway.

Edit 2: Would I have to worry about endian differences and swap the bytes in certain places?

 

Would I have to worry about endian differences and swap the bytes in certain places?

Don't know, hope not.

 

Hey, I'd like to start modding Cave Story on OS X.
Maybe we should consider writing a patching application? We could make it possible for mods to come in separate files maybe.

I'll start checking out the hex and stuff - I'll post anything I find here.
My AIM is "imn0tthefbi" for anyone who wants to discuss CS mac modding.