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@ -1,10 +1,12 @@
---
title: Folder Structure
title: Getting Started
layout: default
root: ../..
idx: 1.1
description: Learn how to make a mod folder, including init.lua, depends.txt and more.
redirect_from: /en/chapters/folders.html
redirect_from:
- /en/chapters/folders.html
- /en/basics/folders.html
---
## Introduction
@ -29,32 +31,51 @@ A "mod name" is used to refer to a mod. Each mod should have a unique mod name.
Mod names can include letters, numbers, and underscores. A good mod name should
describe what the mod does, and the folder which contains the components of a mod
needs to be given the same name as the mod name.
To find out if a mod name is available, try searching for it on
[content.minetest.net](https://content.minetest.net).
### Mod Folder Structure
Mod name (eg: "mymod")
- init.lua - the main scripting code file, which runs when the game loads.
- (optional) depends.txt - a list of mods that need to be loaded before this mod.
- mod.conf - a list of mods that need to be loaded before this mod.
- (optional) textures/ - images used by the mod, commonly in the format modname_itemname.png.
- (optional) sounds/ - sounds used by the mod.
- (optional) models/ - 3d models used by the mod.
...and any other Lua files to be included.
Only the init.lua file is required in a mod for it to run on game load; however,
the other items are needed by some mods to perform their functionality.
Only the init.lua file is actually required in a mod for it to run on game load;
however, mod.conf is recommended and other components may be needed
to perform a mod's functionality.
## Dependencies
The depends text file allows you to specify which mods this mod requires to run and what
needs to be loaded before this mod.
A dependency is another mod which the mod requires to be loaded before itself.
The mod may require the other's mods code, items, or other resources to be available.
There are two types of dependencies: hard and optional dependencies.
Both require the mod to be loaded first, but a hard dependency will cause the mod to
fail to load if the required mod isn't available.
An optional dependency is useful if you want to optionally support another mod if the
user wishes to use it.
**depends.txt**
### mod.conf
Dependencies should be listed in mod.conf.
The file is used for mod metadata such as the mod's name, description, and other information.
name = mymod
description = Adds foo, bar, and bo
depends = modone, modtwo
optional_depends = modthree
### depends.txt
For compatibility with 0.4.x versions of Minetest, you'll need to also provide
a depends.txt file:
modone
modtwo
modthree?
As you can see, each modname is on its own line.
Each modname is on its own line.
Mod names with a question mark following them are optional dependencies.
If an optional dependency is installed, it is loaded before the mod;
however, if the dependency is not installed, the mod still loads.
@ -67,7 +88,6 @@ Mods can be grouped into mod packs which allow multiple mods to be packaged
and moved together. They are useful if you want to supply multiple mods to
a player but don't want to make them download each one individually.
### Mod Pack Folder Structure
modpackfolder/
- modone/
- modtwo/
@ -83,8 +103,9 @@ Are you confused? Don't worry, here is an example which puts all of this togethe
mymod/
- textures/
- - mymod_node.png
- init.lua
- depends.txt
- init.lua
- mod.conf
### depends.txt
@ -108,7 +129,20 @@ minetest.register_node("mymod:node", {
})
{% endhighlight %}
This mod has the name "mymod". It has two text files: init.lua and depends.txt.\\
The script prints a message and then registers a node which will be explained in the next chapter.\\
The depends text file adds a dependency on the default mod which is in minetest_game.\\
### mod.conf
name = mymod
descriptions = Adds a node
depends = default
This mod has the name "mymod". It has three text files: init.lua, mod.conf,
and depends.txt.\\
The script prints a message and then registers a node
which will be explained in the next chapter.\\
There's a single dependency, the
[default mod](https://content.minetest.net/metapackages/default/) which is
usually found in Minetest Game.\\
There is also a texture in textures/ for the node.
Please note that a *game* is not a modpack.
Games have their own organisational structure which will be explained in the
Games chapter.

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@ -1,5 +1,5 @@
---
title: Lua Scripts
title: Lua Scripting
layout: default
root: ../..
idx: 1.2
@ -12,19 +12,22 @@ redirect_from: /en/chapters/lua.html
In this chapter we will talk about scripting in Lua, the tools required,
and go over some techniques which you will probably find useful.
* Tools
* Recommended Editors
* Integrated Programming Environments
* Coding in Lua
* Selection
* Programming
* Local and Global
* Including other Lua Scripts
* [Code Editors](#code-editors)
* [Integrated Programming Environments](#integrated-programming-environments)
* [Coding in Lua](#coding-in-lua)
* [Program Flow](#program-flow)
* [Variable Types](#variable-types)
* [Arithmetic Operators](#arithmetic-operators)
* [Selection](#selection)
* [Logical Operators](#logical-operators)
* [Programming](#programming)
* [Local and Global Scope](#local-and-global-scope)
* [Including other Lua Scripts](#including-other-lua-scripts)
## Tools
## Code Editors
A text editor with code highlighting is sufficient for writing scripts in Lua.
Code highlighting gives different colors to different words and characters
A code editor with code highlighting is sufficient for writing scripts in Lua.
Code highlighting gives different colours to different words and characters
depending on what they mean. This allows you to spot mistakes.
{% highlight lua %}
@ -46,13 +49,12 @@ end
For example, keywords in the above snippet are highlighted such as if, then, end, return.
table.insert is a function which comes with Lua by default.
### Recommended Editors
Here is a list of common editors well suited for Lua.
Other editors are available, of course.
* Windows: [Notepad++](http://notepad-plus-plus.org/), [Atom](http://atom.io/)
* Linux: Kate, Gedit, [Atom](http://atom.io/)
* OSX: [Atom](http://atom.io/)
* Windows: [Notepad++](http://notepad-plus-plus.org/), [Atom](http://atom.io/), [VS Code](https://code.visualstudio.com/)
* Linux: Kate, Gedit, [Atom](http://atom.io/), [VS Code](https://code.visualstudio.com/)
* OSX: [Atom](http://atom.io/), [VS Code](https://code.visualstudio.com/)
### Integrated Programming Environments
@ -71,14 +73,16 @@ One such IDE is Eclipse with the Koneki Lua plugin:
## Coding in Lua
### Program Flow
Programs are a series of commands that run one after another.
We call these commands "statements."
Program flow is important, it allows you to direct or skip over
statements. There are three main types of flow:
Program flow is how these statements are executed.
Different types of flow allow you to skip or jump over sets of commands.
There are three main types of flow:
* Sequence: Just run one statement after another, no skipping.
* Selected: Skip over statements depending on conditions.
* Selection: Skip over sequences depending on conditions.
* Iteration: Repeating, looping. Keep running the same
statements until a condition is met.
@ -92,30 +96,37 @@ a = a + 10
print("Sum is "..result)
{% endhighlight %}
Whoa, what happened there? a, b, and result are **variables**. They're like what
you get in mathematics, A = w * h. The equals signs are **assignments**, so
"result" is set to a + b. Variable names can be longer than one character
unlike in mathematics, as seen with the "result" variable. Lua is **case sensitive**.
A is a different variable than a.
Whoa, what happened there?
The word "local" before they are first used means that they have local scope,
I'll discuss that shortly.
a, b, and result are *variables*. Local variables are declared
by using the local keyword, and then given an initial value.
Local will be discussed in a bit, as it's part of a very important concept called
*scope*.
The `=` means *assignment*, so `result = a + b` means set "result" to a + b.
Variable names can be longer than one character unlike in mathematics, as seen with the "result" variable.
It's also worth noting that Lua is *case-sensitive*; A is a different variable than a.
### Variable Types
A variable will be only one of the following types and can change type after an
assignment.
It's good practice to make sure a variable is only ever nil or a single non-nil type.
| Type | Description | Example |
|----------|----------------------------------------------------|-------------------------------------------|
| Integer | Whole number | local A = 4 |
| Float | Decimal | local B = 3.2, local C = 5 / 2 |
| String | A piece of text | local D = "one two three" |
| Boolean | True or False | local is_true = false, local E = (1 == 1) |
| Table | Lists | Explained below |
| Function | Can run. May require inputs and may return a value | local result = func(1, 2, 3) |
| Nil | Not initialised. The variable is empty, it has no value | `local A`, `D = nil` |
Not an exhaustive list. Doesn't contain every possible type.
| Number | A whole or decimal number. | `local A = 4` |
| String | A piece of text | `local D = "one two three" |
| Boolean | True or False | `local is_true = false`, `local E = (1 == 1)`` |
| Table | Lists | Explained below |
| Function | Can run. May require inputs and may return a value | `local result = func(1, 2, 3)` |
### Arithmetic Operators
Not an exhaustive list. Doesn't contain every possible operator.
| Symbol | Purpose | Example |
|--------|----------------|---------------------------|
| A + B | Addition | 2 + 2 = 4 |
@ -125,17 +136,12 @@ Not an exhaustive list. Doesn't contain every possible type.
| A ^ B | Powers | 2 ^ 2 = 2<sup>2</sup> = 4 |
| A .. B | Join strings | "foo" .. "bar" = "foobar" |
A string in programming terms is a piece of text.
Not an exhaustive list. Doesn't contain every possible operator.
### Selection
The most basic selection is the if statement. It looks like this:
{% highlight lua %}
local random_number = math.random(1, 100) -- Between 1 and 100.
if random_number > 50 then
print("Woohoo!")
else
@ -177,7 +183,6 @@ and return a value which can be stored.
{% highlight lua %}
local A = 5
local is_equal = (A == 5)
if is_equal then
print("Is equal!")
end
@ -191,16 +196,14 @@ of items, and then turning it into steps that a computer can understand.
Teaching you the logical process of programming is beyond the scope of this book;
however, the following websites are quite useful in developing this:
### Codecademy
[Codecademy](http://www.codecademy.com/) is one of the best resources for learning to 'code',
it provides an interactive tutorial experience.
* [Codecademy](http://www.codecademy.com/) is one of the best resources for
learning to 'code', it provides an interactive tutorial experience.
* [Scratch](https://scratch.mit.edu) is a good resource when starting from
absolute basics, learning the problem solving techniques required to program.\\
Scratch is **designed to teach children** how to program, it isn't a serious
programming language.
### Scratch
[Scratch](https://scratch.mit.edu) is a good resource when starting from absolute basics,
learning the problem solving techniques required to program.\\
Scratch is **designed to teach children** how to program, it isn't a serious programming language.
## Local and Global
## Local and Global Scope
Whether a variable is local or global determines where it can be written to or read to.
A local variable is only accessible from where it is defined. Here are some examples:
@ -257,7 +260,7 @@ dump() is a function that can turn any variable into a string so the programmer
see what it is. The foo variable will be printed as "bar", including the quotes
which show it is a string.
This is sloppy coding, and Minetest will in fact warn you about this:
This is sloppy coding, and Minetest will in fact warn about this:
[WARNING] Assigment to undeclared global 'foo' inside function at init.lua:2
@ -276,12 +279,12 @@ one()
two()
{% endhighlight %}
Nil means **not initialised**. The variable hasn't been assigned a value yet,
doesn't exist, or has been uninitialised. (ie: set to nil)
Remember that nil means **not initialised**.
The variable hasn't been assigned a value yet,
doesn't exist, or has been uninitialised (ie: set to nil).
The same goes for functions. Functions are variables of a special type.
You should make functions as local as much as possible,
as other mods could have functions of the same name.
The same goes for functions. Functions are variables of a special type, and
should be made local, as other mods could have functions of the same name.
{% highlight lua %}
local function foo(bar)
@ -289,8 +292,7 @@ local function foo(bar)
end
{% endhighlight %}
If you want your functions to be accessible from other scripts or mods, it is recommended that
you add them all into a table with the same name as the mod:
API tables should be used to allow other mods to call the functions, like so:
{% highlight lua %}
mymod = {}
@ -305,15 +307,24 @@ mymod.foo("foobar")
## Including other Lua Scripts
You can include Lua scripts from your mod or another mod like this:
The recommended way to include other Lua scripts in a mod is to use *dofile*.
{% highlight lua %}
dofile(minetest.get_modpath("modname") .. "/script.lua")
{% endhighlight %}
"local" variables declared outside of any functions in a script file will be local to that script.
You won't be able to access them from any other scripts.
A script can return a value, which is useful for sharing private locals:
As for how you divide code up into files, it doesn't matter that much.
The most important thing is that your code is easy to read and edit.
You won't need to use it for smaller projects.
{% highlight lua %}
-- script.lua
return "Hello world!"
-- init.lua
local ret = dofile(minetest.get_modpath("modname") .. "/script.lua")
print(ret) -- Hello world!
{% endhighlight %}
Later chapters will discuss how to split up the code of a mod in a lot of detail.
However, the simplistic approach for now is to have different files for different
types of things - nodes.lua, crafts.lua, craftitems.lua, etc.

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