How to make a Core mods

[Mew]

I was wondering, how would I go about making a core mod? From what I understand, core mods allow you to "edit" base classes without actually editing them. And if that is true, then I definitely need it for my mod.

 

And I believe this is done with ASM transformers? How would I use those?

[cy]

I've never made one, but it looks like you just sort of... compile your replacement code and paste it into the .class file, or perhaps the memory image of the class file? Like with any bytecode, if you literally just write in instructions after an instruction in the bytecode, then those instructions you added will happen ater the one you inserted after, and before the one after that. (conditionals nonwithstanding)

[Mew]

Hmm... maybe....

 

 

What I really want to know is what a core mod does, and what are good uses for them

[Mew]

Hmm... I'm thinking that if I want to give the vanilla items custom abilities then I should use this...

[Mew]

So, what are good uses for core mods?

[SanAndreaP]

So, what are good uses for core mods?

 

Well, my future coremod will inject a new method in the Item class, which gets called by injected code in the EntityPlayerSP class. Also it creates some public getters and setters for stuff. But it's more worth it if you actually want to inject or edit a code snippet / a (new) method / interface / etc.

[Mew]

Ahh. Thank you good sir. Jolly good show wot?