This is for code contributions. For translations, see TRANSLATING.
Specifically, IntelliJ IDEA. Download the (free) Community Edition of it here. Some people use other tools, like VS Code, but I would personally not recommend them for Java development.
Do not submit something without at least running the game to see if it compiles.
If you are submitting a new block, make sure it has a name and description, and that it works correctly in-game. If you are changing existing block mechanics, test them out first.
If you are interested in adding a large mechanic/feature or changing large amounts of code, first contact me (Anuken) via Discord (preferred method) or via e-mail ([email protected]).
For most changes, this should not be necessary. I just want to know if you're doing something big so I can offer advice and/or make sure you're not wasting your time on it.
This means:
- No spaces around parentheses:
if(condition){
,SomeType s = (SomeType)object
- Same-line braces.
- 4 spaces indentation
camelCase
, even for constants or enums. Why? BecauseSCREAMING_CASE
is ugly, annoying to type and does not achieve anything useful. Constants are less dangerous than variables, not more.- No underscores for anything. (Yes, I know
Bindings
violates this principle, but that's for legacy reasons and really should be cleaned up some day)
Import this style file into IntelliJ to get correct formatting when developing Mindustry.
Android does not support many of Java 8's features, such as the packages java.util.function
, java.util.stream
or forEach
in collections. Do not use these in your code.
If you need to use functional interfaces, use the ones in io.anuke.arc.func
, which are more or less the same with different naming schemes.
The same applies to any class outside of the standard java.[n]io
/ java.net
/ java.util
packages: Most of them are not supported.
java.awt
is one of these packages: do not use it, ever. It is not supported on any platform, even desktop - the entire package is removed during JRE minimization.
In general, if you are using IntelliJ, you should be warned about platform incompatiblities.
Instead of using java.util.List
, java.util.HashMap
, and other standard Java collections, use Array
, ObjectMap
and other equivalents from io.anuke.arc.collection
.
Why? Because that's what the rest of the codebase uses, and the standard collections have a lot of cruft and usability issues associated with them.
In the rare case that concurrency is required, you may use the standard Java classes for that purpose (e.g. CopyOnWriteArrayList
).
What you'll usually need to change:
HashSet
->ObjectSet
HashMap
->ObjectMap
List
/ArrayList
/Stack
->Array
java.util.Queue
->io.anuke.arc.collection.Queue
- Many others
Never create variables or collections with boxed types Array<Integer>
or ObjectMap<Integer, ...>
. Use the collections specialized for this task, e.g. IntArray
and IntMap
.
Never allocate new
objects in the main loop. If you absolutely require new objects, use Pools
to obtain and free object instances.
Otherwise, use the Tmp
variables for things like vector/shape operations, or create static
variables for re-use.
If using a list, make it a static variable and clear it every time it is used. Re-use as much as possible.
This is situational, but in essence what it means is to avoid using any sort of getters and setters unless absolutely necessary. Public or protected fields should suffice for most things. If something needs to be encapsulated in the future, IntelliJ can handle it with a few clicks.
Unless a block of code is very large or used in more than 1-2 places, don't split it up into a separate method. Making unnecessary methods only creates confusion, and may slightly decrease performance.