Development: Difference between revisions

Either use "..." or "etc.", but not both
mNo edit summary
 
(17 intermediate revisions by 4 users not shown)
Line 1: Line 1:
{{LangNavBox}}
{{MigrateTranslation}}
<languages/>
<translate>
<!--T:1-->
This article aims to introduce you into DDNet '''''development''''', since it's an open-source game, it relies on random people kind enough to contribute to it on their free time.
This article aims to introduce you into DDNet '''''development''''', since it's an open-source game, it relies on random people kind enough to contribute to it on their free time.


== Your development environment ==


== Your development environment == <!--T:2-->
<!--T:3-->
It is extremely recommended to set up a Linux environment to begin programming in DDNet for the following reasons (as of now):
It is extremely recommended to set up a Linux environment to begin programming in DDNet for the following reasons (as of now):
* Most DDNet contributors actually use Linux to contribute.
* Most DDNet contributors actually use Linux to contribute.
Line 9: Line 14:
* This article doesn't have yet a Windows version and is focused on Linux.
* This article doesn't have yet a Windows version and is focused on Linux.


<!--T:4-->
First an foremost, DDNet is coded using the C++ programming language, you will need to be fairly familiar with it, but you can also know the basics and learn more with it.
First an foremost, DDNet is coded using the C++ programming language, you will need to be fairly familiar with it, but you can also know the basics and learn more with it.


<!--T:5-->
Some useful resources to learn C++:
Some useful resources to learn C++:
* [https://www.cplusplus.com/doc/tutorial/ cplusplus tutorial]
* [https://www.learncpp.com/ learncpp.com]
* [https://en.cppreference.com/w/ cppreference.com]
* [https://en.cppreference.com/w/ cppreference.com]
* Your search engine of preference
* Your search engine of preference


<!--T:6-->
The source code of DDNet is managed using [https://git-scm.com/ Git], a version control system, an essential tool to collaborate with multiple developers.
The source code of DDNet is managed using [https://git-scm.com/ Git], a version control system, an essential tool to collaborate with multiple developers.


<!--T:7-->
If you don't have git yet in your Linux distribution, make sure to install it, for example in most debian/ubuntu based distributions: <code>sudo apt install git</code>.
If you don't have git yet in your Linux distribution, make sure to install it, for example in most debian/ubuntu based distributions: <code>sudo apt install git</code>.


== Getting the source code ==
 
== Getting the source code == <!--T:8-->
 
<!--T:9-->
The source code is located on [https://github.com/ddnet/ddnet Github], you can get the source code by cloning without the need of an account, but if you want to ever put your changes to the official source code you will need one.
The source code is located on [https://github.com/ddnet/ddnet Github], you can get the source code by cloning without the need of an account, but if you want to ever put your changes to the official source code you will need one.


<!--T:10-->
If you are not familiar with git/github you can learn the basics here: [https://docs.github.com/en/get-started/quickstart/hello-world Hello World - Github]
If you are not familiar with git/github you can learn the basics here: [https://docs.github.com/en/get-started/quickstart/hello-world Hello World - Github]


== Installing the dependencies ==


== Installing the dependencies == <!--T:11-->
<!--T:12-->
If you are on Linux, you can install all the needed dependencies by reading the README on the DDNet github page: https://github.com/ddnet/ddnet#dependencies-on-linux--macos
If you are on Linux, you can install all the needed dependencies by reading the README on the DDNet github page: https://github.com/ddnet/ddnet#dependencies-on-linux--macos


<!--T:13-->
For Arch Linux:
For Arch Linux:


<code>sudo pacman -S --needed base-devel cmake curl freetype2 git glew gmock libnotify opusfile python sdl2 sqlite wavpack</code>
<!--T:14-->
<syntaxhighlight lang="bash">
sudo pacman -S --needed base-devel cmake curl ffmpeg freetype2 git glew glslang gmock libnotify libpng opusfile python rust sdl2 spirv-tools sqlite vulkan-headers vulkan-icd-loader wavpack x264
</syntaxhighlight>
 
For Debian:
 
<syntaxhighlight lang="bash">
sudo apt install build-essential cargo cmake git glslang-tools google-mock libavcodec-extra libavdevice-dev libavfilter-dev libavformat-dev libavutil-dev libcurl4-openssl-dev libfreetype6-dev libglew-dev libnotify-dev libogg-dev libopus-dev libopusfile-dev libpng-dev libsdl2-dev libsqlite3-dev libssl-dev libvulkan-dev libwavpack-dev libx264-dev python rustc spirv-tools4
</syntaxhighlight>


== Compiling DDNet ==
== Compiling DDNet == <!--T:15-->


<!--T:16-->
We use CMake to control the compilation process, if you have all the dependencies installed, it's as easy as following these commands (make sure you are on the DDNet folder):
We use CMake to control the compilation process, if you have all the dependencies installed, it's as easy as following these commands (make sure you are on the DDNet folder):


<!--T:17-->
<syntaxhighlight lang="bash">
<syntaxhighlight lang="bash">
mkdir build
mkdir build
Line 44: Line 71:
</syntaxhighlight>
</syntaxhighlight>


== General information ==


== General information == <!--T:18-->
<!--T:19-->
Here are some general bits of information:
Here are some general bits of information:
* Currently, the source code is compiled with the C++17 standard, but you will see that many parts of the code are more C-like since only mostly new code uses C++17 stuff.
* Currently, the source code is compiled with the C++17 standard, but you will see that many parts of the code are more C-like since only mostly new code uses C++17 stuff.
Line 51: Line 80:
* Most I/O code, formatting and printing is done using <code>system.h</code> provided methods.
* Most I/O code, formatting and printing is done using <code>system.h</code> provided methods.


== The source code layout ==
 
== The source code layout == <!--T:20-->
 
<!--T:21-->
Now that you can build DDNet you can begin editing it.
Now that you can build DDNet you can begin editing it.


=== The src/base directory ===
 
=== The src/base directory === <!--T:22-->
 
<!--T:23-->
Since DDNet is a cross-platform game, an abstraction layer over that is needed to make development easier, this directory contains many useful functions to handle that.
Since DDNet is a cross-platform game, an abstraction layer over that is needed to make development easier, this directory contains many useful functions to handle that.


=== The src/engine directory ===
 
=== The src/engine directory === <!--T:24-->
 
<!--T:25-->
Here lies the game engine, it handles most stuff that is not gameplay related, such as graphics, sound, network, etc.
Here lies the game engine, it handles most stuff that is not gameplay related, such as graphics, sound, network, etc.


=== The src/game directory ===
 
=== The src/game directory === <!--T:26-->
 
<!--T:27-->
All gameplay related code is here, separated into client and server.
All gameplay related code is here, separated into client and server.


==== Server side ====
This game uses its own [https://en.wikipedia.org/wiki/Entity_component_system Entity Component System], the main class to which all other entities derive from is <code>CEntity</code> located in <code>src/game/server/entity.h</code>.


==== Server side ==== <!--T:28-->
<!--T:29-->
This game uses its own hierarchical object-oriented entity system, the main class to which all other entities derive from is <code>CEntity</code> located in <code>src/game/server/entity.h</code>.
<!--T:30-->
These entities are managed by the game world located here <code>src/game/server/gameworld.h</code>
These entities are managed by the game world located here <code>src/game/server/gameworld.h</code>


<!--T:31-->
Some important entities are:
Some important entities are:


* [https://github.com/ddnet/ddnet/blob/master/src/game/server/entities/character.h CCharacter]: Represents a [[Common_Terminology#Tee|tee]] that is alive, it is instantiated when a tee spawns and deleted when it dies. For information about the player kept between deaths, see [https://github.com/ddnet/ddnet/blob/master/src/game/server/player.h CPlayer].
<!--T:32-->
* [https://github.com/ddnet/ddnet/blob/master/src/game/server/entities/character.h CCharacter]: Represents a [[Special:MyLanguage/Common_Terminology#Tee|tee]] that is alive, it is instantiated when a tee spawns and deleted when it dies. For information about the player kept between deaths, see [https://github.com/ddnet/ddnet/blob/master/src/game/server/player.h CPlayer].
 


==== Client side ====
==== Client side ==== <!--T:33-->
 
<!--T:34-->
The client side is made up of components, these are classes that inherit <code>CComponent</code>: These components can implement the virtual methods such as <code>OnInit</code>, <code>OnMessage</code>, etc. to provide their functionality.
The client side is made up of components, these are classes that inherit <code>CComponent</code>: These components can implement the virtual methods such as <code>OnInit</code>, <code>OnMessage</code>, etc. to provide their functionality.


==== Networking ====
 
==== Networking ==== <!--T:35-->
 
<!--T:36-->
The network protocol is mostly generated by python scripts that output C++ code, for example, <code>datasrc/network.py</code> defines all network packets.
The network protocol is mostly generated by python scripts that output C++ code, for example, <code>datasrc/network.py</code> defines all network packets.


== Code conventions ==
 
== Code conventions == <!--T:37-->
 
<!--T:38-->
The ongoing discussion on code conventions is located here: [https://github.com/ddnet/ddnet/issues/2945 ddnet#2945]
The ongoing discussion on code conventions is located here: [https://github.com/ddnet/ddnet/issues/2945 ddnet#2945]


<!--T:39-->
Currently, the following applies:
Currently, the following applies:


=== Indentation style ===
 
=== Indentation style === <!--T:40-->
 
<!--T:41-->
[https://en.wikipedia.org/wiki/Indentation_style#Allman_style Allman style] is used.
[https://en.wikipedia.org/wiki/Indentation_style#Allman_style Allman style] is used.


<!--T:42-->
<blockquote>
<blockquote>
This style puts the brace associated with a control statement on the next line, indented to the same level as the control statement. Statements within the braces are indented to the next level.
This style puts the brace associated with a control statement on the next line, indented to the same level as the control statement. Statements within the braces are indented to the next level.
</blockquote>
</blockquote>


<!--T:43-->
<syntaxhighlight lang="cpp">
<syntaxhighlight lang="cpp">
while (x == y)
while(x == y)
{
{
     Something();
     Something();
Line 97: Line 159:
}
}


Finalthing();
<!--T:44-->
FinalThing();
</syntaxhighlight>
</syntaxhighlight>


=== Classes and Structs ===
=== Classes and Structs === <!--T:45-->
Must be prefixed by <code>C</code> (for legacy reasons this is ignored for structs in some places, such as in graphics code) or <code>I</code> for interfaces.
 
<!--T:46-->
Must be prefixed by <code>C</code> (for legacy reasons this is ignored for structs in some places, such as in graphics code) or <code>I</code> for interfaces. New <code>struct</code>s should be prefixed by <code>S</code>.


<!--T:47-->
Example:
Example:


<!--T:48-->
<syntaxhighlight lang="cpp">
<syntaxhighlight lang="cpp">
class CCharacter : public CEntity
class CCharacter : public CEntity
Line 112: Line 179:
</syntaxhighlight>
</syntaxhighlight>


=== Enums and constants ===
 
=== Enums and constants === <!--T:49-->
 
<!--T:50-->
Should be screaming snake case, for example: <code>MAX_PLAYERS</code>
Should be screaming snake case, for example: <code>MAX_PLAYERS</code>


<!--T:51-->
<syntaxhighlight lang="cpp">
<syntaxhighlight lang="cpp">
enum
enum
Line 128: Line 199:
</syntaxhighlight>
</syntaxhighlight>


=== Variable naming ===
 
=== Variable naming === <!--T:52-->
 
<!--T:53-->
* The names of variables contain 3 parts: qualifier, prefix and name.
* The names of variables contain 3 parts: qualifier, prefix and name.
* Variable names should start with uppercase unless they are 1 char long without any prefix or qualifier, for example: <code>i</code>, <code>x</code>, <code>y</code>.
* Variable names should start with uppercase unless they are 1 char long without any prefix or qualifier, for example: <code>i</code>, <code>x</code>, <code>y</code>.
* Variables can have more than 1 qualifier (or zero) and more than 1 prefix (or zero).
* Variables can have more than 1 qualifier (or zero) and more than 1 prefix (or zero).


<!--T:54-->
These are laid out like this: <code>[qualifiers]_[prefixes][Name]</code>
These are laid out like this: <code>[qualifiers]_[prefixes][Name]</code>


==== Qualifiers ====
 
==== Qualifiers ==== <!--T:55-->
 
<!--T:56-->
* <code>m</code> for member variables: <code>m_MyVariable</code>.
* <code>m</code> for member variables: <code>m_MyVariable</code>.
* <code>s</code> for static variables: <code>s_MyStaticVariable</code>.
* <code>s</code> for static variables: <code>s_MyStaticVariable</code>, <code>ms_MyStaticMemberVariable</code>.
* <code>g</code> for global variables with external linkage: <code>gs_MyGlobalStaticVar</code>.
* <code>g</code> for global variables with external linkage: <code>gs_MyGlobalStaticVar</code>.


==== Prefixes ====
 
==== Prefixes ==== <!--T:57-->
 
<!--T:58-->
* <code>p</code> for pointers: <code>pMyPointer</code>, <code>m_pCharacter</code>, <code>ppMyPointerToPointer</code>.
* <code>p</code> for pointers: <code>pMyPointer</code>, <code>m_pCharacter</code>, <code>ppMyPointerToPointer</code>.
* <code>a</code> for arrays: <code>aMyArray</code>, <code>aBuf</code>.
* <code>a</code> for arrays: <code>aMyArray</code>, <code>aBuf</code>.
* <code>v</code> for <code>std::vector</code>s: <code>vMyVector</code>, <code>vpvMyVectorOfPointersToVectors</code>.
* <code>fn</code> for functions: <code>pfnMyCallback</code>, <code>m_papfnMyPointerToArrayOfCallbacks</code>.
* <code>fn</code> for functions: <code>pfnMyCallback</code>, <code>m_papfnMyPointerToArrayOfCallbacks</code>.


== Common snippets ==
 
== Common snippets == <!--T:59-->
 
<!--T:60-->
Here is a list of code that you may frequently see across the codebase:
Here is a list of code that you may frequently see across the codebase:


=== Formatting text ===


=== Formatting text === <!--T:61-->
<!--T:62-->
<syntaxhighlight lang="cpp">
<syntaxhighlight lang="cpp">
char aBuf[128];
char aBuf[128];
Line 155: Line 242:
</syntaxhighlight>
</syntaxhighlight>


=== Iterating over all players ===
See [https://cplusplus.com/reference/cstdio/printf/ printf documentation] for a list of all format specifiers.
=== Iterating over all players === <!--T:63-->


<!--T:64-->
<syntaxhighlight lang="cpp">
<syntaxhighlight lang="cpp">
for(int i = 0; i < MAX_CLIENTS; i++)
for(int i = 0; i < MAX_CLIENTS; i++)
Line 165: Line 254:
</syntaxhighlight>
</syntaxhighlight>


=== Printing to the game console ===


=== Printing to the game console === <!--T:65-->
<!--T:66-->
<syntaxhighlight lang="cpp">
<syntaxhighlight lang="cpp">
Console()->Print(IConsole::OUTPUT_LEVEL_STANDARD, "wikiprint", "Hello from the ddnet wiki!");
Console()->Print(IConsole::OUTPUT_LEVEL_STANDARD, "wikiprint", "Hello from the ddnet wiki!");
</syntaxhighlight>
</syntaxhighlight>


=== Debug printing ===


=== Debug printing === <!--T:67-->
<!--T:68-->
<syntaxhighlight lang="cpp">
<syntaxhighlight lang="cpp">
int i = 2;
int i = 2;
Line 178: Line 272:
</syntaxhighlight>
</syntaxhighlight>


== External resources ==
=== Translating text in the client ===
<code>Localize</code> can be used in the game client to get the translation for a specific string from the language file selected by the user.<syntaxhighlight lang="cpp">
DoButton(..., Localize("Connect"), ...);
</syntaxhighlight>The string can also contain format specifiers. The translated string must contain the same format specifiers.<syntaxhighlight lang="cpp">
char aBuf[128];
str_format(aBuf, sizeof(aBuf), Localize("%d of %d servers"), NumServers, TotalServers);
</syntaxhighlight>A script is used to scan the code for calls to <code>Localize</code> and collect the strings to update the translation files. For this reason, the call to <code>Localize</code> must not contain any other code, or the script cannot determine the text correctly.<syntaxhighlight lang="cpp">
// Do NOT do this:
const char *pStr = Localize(Team == TEAM_RED ? "Red team" : "Blue team");
 
// Do this instead:
const char *pStr = Team == TEAM_RED ? Localize("Red team") : Localize("Blue team");
</syntaxhighlight>
 
== External resources == <!--T:69-->


* [https://edgarluque.com/blog/intro-to-ddnet/ An intro to the DDraceNetwork game source code]  by [[User:Ryozuki|Ryozuki]]
<!--T:70-->
* [https://edgarluque.com/blog/code-conventions-in-ddnet/ Code conventions in DDraceNetwork]  by [[User:Ryozuki|Ryozuki]]
* [https://edgarluque.com/blog/ui-code-ddnet/ UI Code in DDraceNetwork] by [[Special:MyLanguage/User:Ryozuki|Ryozuki]]
* [https://edgarluque.com/blog/chat-command-ddracenetwork/ Implementing a chat command in DDraceNetwork]  by [[User:Ryozuki|Ryozuki]]
* [https://edgarluque.com/blog/intro-to-ddnet/ An intro to the DDraceNetwork game source code]  by [[Special:MyLanguage/User:Ryozuki|Ryozuki]]
* [https://wiki.ddnet.tw/docs/ Auto generated docs]
* [https://edgarluque.com/blog/code-conventions-in-ddnet/ Code conventions in DDraceNetwork]  by [[Special:MyLanguage/User:Ryozuki|Ryozuki]]
* [https://ddnet.tw/libtw2-doc/ Technical documentation of Teeworlds file formats and network protocol]
* [https://edgarluque.com/blog/chat-command-ddracenetwork/ Implementing a chat command in DDraceNetwork]  by [[Special:MyLanguage/User:Ryozuki|Ryozuki]]
* [https://codedoc.ddnet.org/ Auto generated docs]
* [https://ddnet.org/libtw2-doc/ Technical documentation of Teeworlds file formats and network protocol]
* [https://heinrich5991.github.io/blog/blog/one-tick-unfreeze The Anatomy of a One Tick Unfreeze]
* [https://heinrich5991.github.io/blog/blog/one-tick-unfreeze The Anatomy of a One Tick Unfreeze]
* [https://www.youtube.com/playlist?list=PLhJkqAQmOh5LyYOfnMy4PJB6CSZltQyTc Teeworlds programming YouTube tutorial] by ChillerDragon
* [https://www.youtube.com/playlist?list=PLhJkqAQmOh5LyYOfnMy4PJB6CSZltQyTc Teeworlds programming YouTube tutorial] by ChillerDragon
</translate>