How do you find the functions you need to modify (when you know what you want to do)?

[InspectorCaracal]

I'll keep it short. I have a very specific idea of what I want to do, and I have several possible approaches outlined in how to implement it. However, I am being completely stymied by not being able to find any actual library documentation. How is someone new to Forge/Minecraft supposed to find the classes and functions that need to be extended or overloaded in the first place? I know the information has to be around somewhere but I can't find it.

(Disclaimer: I'm an experienced amateur programmer/game dev but have basically no Java-specific experience, and this is my first serious look at making my own mod.)

[Luis_ST]

11 minutes ago, InspectorCaracal said:

I'll keep it short. I have a very specific idea of what I want to do, and I have several possible approaches outlined in how to implement it. However, I am being completely stymied by not being able to find any actual library documentation. How is someone new to Forge/Minecraft supposed to find the classes and functions that need to be extended or overloaded in the first place? I know the information has to be around somewhere but I can't find it.

first of all do you know basic java?

this is the doc of forge:
https://mcforge.readthedocs.io/en/latest/

and this is the forge community wiki:
https://forge.gemwire.uk/wiki/Main_Page

read the docs, after that ask the remaining questions

[InspectorCaracal]

2 hours ago, Luis_ST said:

first of all do you know basic java?

this is the doc of forge:
https://mcforge.readthedocs.io/en/latest/

and this is the forge community wiki:
https://forge.gemwire.uk/wiki/Main_Page

read the docs, after that ask the remaining questions

1. Yes. I am also sufficiently familiar with OOP in general to understand the necessary concepts and to find, understand and reference code examples to implement specific functionality.

2. I've read it.

3. I hadn't seen this one before and it looks very useful, thank you!

 

There! I have done the things you asked. Now, on to my remaining questions. Are those the closest to library documentation that exist for making Forge mods? There is nothing out there that documents, for example, the IGrowable class, what methods it has, etc? Or that would allow you to find out that the IGrowable class exists to define growable plants in the first place?

These docs are very useful for general concepts, and the wiki has a good number of specifics listed in certain categories, but they're still quite general and not what I was asking about.

 

Just in case you're unfamiliar, library documentation is usually something like this (a small display library) or this (a game engine library). They describe the classes, methods, functions, modules, etc. that are available within the library, what parameters they take, and what they're used for. I've been trying to find something similar for Forge to no avail.

Edited June 29, 2021 by InspectorCaracal
additional info

[Luis_ST]

25 minutes ago, InspectorCaracal said:

There! I have done the things you asked. Now, on to my remaining questions. Are those the closest to library documentation that exist for making Forge mods? There is nothing out there that documents, for example, the IGrowable class, what methods it has, etc? Or that would allow you to find out that the IGrowable class exists to define growable plants in the first place?

unfortunately most of the methods have no comments,
there are only a few ways to find out what a method does

1. find out for yourself what the method does
2. ask for help here in the forum or on the discord server
3. simple logic e.g.: World#setBlock -> set the block to a position in the world
4. look for a code example, for most things there are examples of vanilla else look in the www.
5. testing...

38 minutes ago, InspectorCaracal said:

for example, the IGrowable class, what methods it has, etc? Or that would allow you to find out that the IGrowable class exists to define growable plants in the first place?

look at the interface / and the classes that implement it

Note: if you look in the vanilla classes, only methods and fields have 'correct names',

[InspectorCaracal]

8 minutes ago, Luis_ST said:

unfortunately most of the methods have no comments,
there are only a few ways to find out what a method does

1. find out for yourself what the method does
2. ask for help here in the forum or on the discord server
3. simple logic e.g.: World#setBlock -> set the block to a position in the world
4. look for a code example, for most things there are examples of vanilla else look in the www.
5. testing...

look at the interface / and the classes that implement it

Note: if you look in the vanilla classes, only methods and fields have 'correct names',

Okay, great! Well, great in the sense that this answers my question with "unfortunately it doesn't exist", oh nooo.

That all makes sense for figuring out how things work, but how do people go the other way - if you know the thing that happens, how do you find the method that controls it?

I'm specifically looking into campfires, beehives/nests and bees, and I've collected all the relevant information about tags, block states etc. that's available on the official Minecraft wiki, but I was hoping to get a look at how exactly those interact. Is trial and error really the only way?

[kiou.23]

51 minutes ago, InspectorCaracal said:

I'm specifically looking into campfires, beehives/nests and bees, and I've collected all the relevant information about tags, block states etc. that's available on the official Minecraft wiki, but I was hoping to get a look at how exactly those interact. Is trial and error really the only way?

I'd start by reading the beehive and the campfire methods... and looking for lines of code that handle the interaction.

for instance, does the campfire or the beehive have a tile entity? if so that logic could be handle in the tick method. if not it's probably done through random ticks, which is done in the tickRandomly (iirc) of the block.

the beehive was added in a later update, and the logic concerns it's state and doesn't affect the campfire, so I'd assume that it is handled somewhere in beehive related code.

reading through the vanilla classes is how to get around and understand, for the most part

[InspectorCaracal]

3 hours ago, kiou.23 said:

I'd start by reading the beehive and the campfire methods... and looking for lines of code that handle the interaction.

for instance, does the campfire or the beehive have a tile entity? if so that logic could be handle in the tick method. if not it's probably done through random ticks, which is done in the tickRandomly (iirc) of the block.

the beehive was added in a later update, and the logic concerns it's state and doesn't affect the campfire, so I'd assume that it is handled somewhere in beehive related code.

reading through the vanilla classes is how to get around and understand, for the most part

Ohhh. Okay! I've been trying to find the vanilla code and also not been able to find anything about where it is, so it sounds like that's the root of my problem. Where is it?

(And yeah, my best guess is that the check is done on the hive itself, so that's where I wanted to look first.)

Edited June 30, 2021 by InspectorCaracal

[kiou.23]

2 hours ago, InspectorCaracal said:

Ohhh. Okay! I've been trying to find the vanilla code and also not been able to find anything about where it is, so it sounds like that's the root of my problem. Where is it?

(And yeah, my best guess is that the check is done on the hive itself, so that's where I wanted to look first.)

you can check the code using your IDE, it should have a code navigation feature, which allows you to read class definitions, method references, interface implementations and all that
I believe that in IntelliJ you can press double shift to search for files, and in there you can search for the source.

[InspectorCaracal]

12 hours ago, kiou.23 said:

you can check the code using your IDE, it should have a code navigation feature, which allows you to read class definitions, method references, interface implementations and all that
I believe that in IntelliJ you can press double shift to search for files, and in there you can search for the source.

Ah, great! I only just finished setting all that up last night, I'll take a look through it today. You've been a huge help, thanks so much!