View source for SDK Overview

__NOTOC__
[[Category:SDK_Documentation]]
<div style="max-width:75%;min-width:80ch;margin:0 auto;font-size:1.1em;line-height:1.65em">
= What is the SDK =
The {{User:SomeoneTookSeven/TemplateSDK}} is a development kit for creating and modifying games built on the {{source|4|nt=1}}. It includes the relevant source code files that enable developers to modify and create internal games systems. While the {{User:SomeoneTookSeven/TemplateSDK}} does not provide access to the engine, it does provide header files. These header files can be used in conjunction with other SDK code to interface with the engine allowing communication between the public SDK code and {{Valve|4|nt=3|addtext=s}} Closed-source engine code.

== What The SDK '''Isnt''' ==
It’s important to understand that the {{User:SomeoneTookSeven/TemplateSDK}} '''''DOES NOT''''' include {{source|4|nt=1}} code. This means that while you can interface with low level systems, you '''cannot change them'''. However anything above those systems, you can! While its obvious that the game code is available. {{Valve|4|nt=3}} also included other {{Visual Studio|4|nt=4}} projects along with the SDK ''(like compiler tools)''

== How the SDK Operates  ==
As we described earlier The {{User:SomeoneTookSeven/TemplateSDK}} '''IS NOT''' The {{source|4|nt=1}}. This means we are still going to need the engine to run our game. To get this engine, {{Valve|4|nt=3}} published {{Source SDK Base 2013 Multiplayer|4|nt=4}} on steam. Downloading this software off steam, grants us a relatively barebones version of the engine that we will use to launch our SDK mod.


Valve designed the engine from the ground up to be highly modular. As you start reviewing SDK Code you should see this pattern emerge. At the lowest level the engine will dynamically load and unload <code>.dll</code> files depending on what logic is needed and when. This means that we can launch our SDK using the original {{Half-Life 2|4|nt=0|addtext=.exe}} without needing to recompile the entire engine. Instead all that is required from us is tell the <code>.exe</code> file that we want to use our SDK code instead of the original.


This happens by using launch parameters. The SDK should setup this up for you automatically without you realizing it. If you inspect the properties of the <code>Client (HL2MP)</code> project in {{Visual Studio|4}} under <code>Configuration Properties -> Debugging -> Command</code> you should find it set to: <code><drive>\STEAM\steamapps\common\Source SDK Base 2013 Multiplayer\hl2_win64.exe</code> This is telling you that whenever you build your SDK project and launch it to use this <code>.exe</code> program to try and do it. Just under it you'll notice <code>Command Arguments</code> ''(what it will pass the the <code>.exe</code> program as it trys to launch it)'' is set to: <code>-game "C:\Users\User\Desktop\SDK\source-sdk-2013\game\mod_hl2mp" -dev -w 1920 -h 1080 -windowed</code>. These arguments is what tells the source engine to launch our mod.

== Getting Started ==
Now that you know the fundamentals of what the {{User:SomeoneTookSeven/TemplateSDK}} is and what it actually does. You start exploring the codebase. With this being said, {{source|4}} is '''''LARGE''''' and really old ''(potentially older than some of its developers)'' meaning its recommended you take some more time to learn about some generic SDK concepts as well as some generic {{Cpp|4}} concepts that are used heavily throughout the engine. 


The next article that is recommended is [[VPC_Scripts]]. These "Valve Project Creator" scripts is how {{Valve|4|nt=3}} ensures everyone on their team is working in a relatively consistent development environment. They do this by controlling project settings and some pre-processor functionalities with these scripts allowing everyone on the team to have a uniform baseline project.