We're going to set up a C++ coding environment to build our UE4 applications. We'll download Visual Studio 2017, install it, and set it up for UE4 C++ coding.

You can Sign inwith your Microsoft account (the one you use to sign into Windows 10) orSign upfor a new account. After you've signed in or signed up, you will be able to sign into Visual Studio itself. It may seem odd to sign into a desktop code editing program, but your sign-in will be used for source control commits to your repositories. On first signing into Visual Studio, you can select (one time only) a unique URL for yoursourcecode repositories, as hosted on Visualstudio.com (https://visualstudio.microsoft.com/).

Visual Studio is an excellent editor, and you will have a fantastic time coding within it. In the next recipe, we'll discuss how to create and compile our own code.

In this recipe, we will identify how to create an actual executable running program from Visual Studio. We will do so by creating a project in Visual Studio to host, organize, and compile the code.

In Visual Studio, each group of code is contained within something called a Project. A project is a buildable conglomerate of code and assets that produce either an executable (.exe runnable) or a library (.lib or .dll). A group of projects can be collected into something called a Solution. Let's start by constructing a Visual Studio solution and a project for a console application, followed by constructing a UE4 sample project and solution:

Once the application wizard completes, you will have created your first project. Both a solution and a project will be created.

Solution Explorer location

The Solution Explorer also displays all the files that are part of the project. This default solution already contains a few files, and we can add and remove new files in this section from here. As your project grows, more and more files are going to be added to your project. In the Source Files folder, you'll also notice a file created called FirstProject.cpp, which will look as follows:

// FirstProject.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include "pch.h"
#include <iostream>

int main()
{
    std::cout << "Hello World!\n"; 
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

// Tips for Getting Started: 
// 1. Use the Solution Explorer window to add/manage files
// 2. Use the Team Explorer window to connect to source control
// 3. Use the Output window to see build output and other messages
// 4. Use the Error List window to view errors
// 5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
// 6. In the future, to open this project again, go to File > Open > Project and select the .sln file

Building an executable involves translating your C++ code from text language into a binary file. Running the file runs your game program, which is just the code text that occurs in the main() function between { and }.

Build configurations are styles of build that we will discuss here. There are at least two important build configurations you should know about: Debug and Release. The Build configuration that's currently selected is at the top of the editor, just below the toolbar in the default position:

Location of the currently selected Build Configuration

Depending on which configuration you select, different compiler options are used. A Debug configuration typically includes extensive debug information in the build, as well as the ability to turn off optimizations to speed up compilation. Release builds are often optimized (either for size or for speed) and take a bit longer to build; they result in smaller or faster executables. Stepping through a file's behavior by moving through with the debugger line by line is often better in the Debug mode than the Release mode.

Visual Studio is a highly customizable code editing tool. You might find the default fonts too small for your screen. This is easily adjustable by holding down the Ctrl key and using the mouse wheel to increase or decrease the size, but you may want to change the default value. Or, perhaps you may want to have more control, as you may want to change your code's font size and color. You may also want to completely customize the coloration of keywords and the text background colors. The Fonts and Colors dialog box, which we'll show you how to use in this section, allows you to completely customize every aspect of the code editor's font and color:

Modified font and colors

Text Editor/Plain Text describes the font and size that's used for all code text within the regular code editor. If you change the size of the font, the size changes for any text that's entered into the coding window (for all languages, including C, C++, C#, and others).

The color (foreground and background) is completely customizable for each item. Try this for the Text Editor/Keyword setting (affects all languages), or for items specific to C++, such as Text Editor/C++ Functions. Click OK, and you will see the changed color of the item reflected in the code editor.

You may also want to configure the font size of the Output Window, under the Show settings for: option, so click on the drop-down and select Output Window, as shown in the following screenshot:

The Output Window is the little window at the bottom of the editor that displays build results and compiler errors.

The Fonts and Colors dialog simply changes the appearance of code in the text editor as well as for other windows, such as the output window. It is very useful for making your coding environment more comfortable.

Once you have customized your settings, you'll find that you may want to save your customized Fonts and Colors settings for others to use, or to put into another installation of Visual Studio, which you have on another machine. Unfortunately, by default, you won't be able to save-out your customized Fonts and Colors settings. You will need something called the Visual Studio Theme Editor extension to do so. We will explore this in the next recipe.

The Color Themes editor page

Once we load the plugin, it integrates into Visual Studio quite nicely. Exporting and uploading your themes to share with others is quite easy too.

Adding a theme to your Visual Studio installs it as an extension in Tools | Extensions and Updates.... To remove a theme, simply Uninstall its extension:

Code has to be formatted correctly. You and your co-programmers will be able to better understand, grok, and keep your code bug-free if it is consistently formatted. This is why Visual Studio includes a number of auto-formatting tools inside the editor.

Automatic brace completion is a feature where, when you type {, a corresponding } is automatically typed for you. This feature may irk you if you don't like the text editor inserting characters for you unexpectedly.

You generally want Auto list members on, as that displays a nice dialog with the complete names of data members listed for you as soon as you start typing. This makes it easy to remember variable names, so you don't have to memorize them:

I recommend using all of the options at first and then disabling them only if they interrupt your workflow.

The default autocomplete and autoformat behaviors may irk you. You need to converse with your team on how you want your code to be formatted (spaces or tab indents, size of indent, and so on), and then configure your Visual Studio settings accordingly.

To get started, you will need to have Visual Studio installed and a project opened to look at the features.

The following are some very useful keyboard shortcuts for you to try:

Note that the being mentioned is the one near the 0 key on your keyboard and will not work with the on the numpad.

Say, for example, you're editing code in one place, and you want to go back to the place you've just been (or go back to the section in the code you came from). Simply press Ctrl + -, and that will warp you back to the location in the code you were at last. To warp forward to the location you were at before, press Ctrl + -, press Ctrl + Shift + -. To warp back, the previous location should be more than 10 lines away, or in a different file. These correspond to the forward and back menu buttons in the toolbar:

As you know, pressing Ctrl + V pastes the top item in the stack. Pressing Ctrl + Shift + Insert accesses a very long history of all the items ever copied in that session, that is, items underneath the top item in the stack. After you exhaust the list of items, the list wraps back to the top item in the stack. This is an odd feature, but you may find it useful occasionally.

Keyboard shortcuts allow you to speed up work in the code editor by reducing the number of mouse- reaches that you have to perform in a coding session.

You can then either cut, copy, or overwrite the box-shaped text area; in the latter case, the characters you type will be repeated in all selected rows.

Mouse-clicking alone can be tedious, but with the help of Ctrl + Alt, it becomes quite cool.

UE4 takes up quite a few GB of space, so you should have at least 20 GB or so free for the installation on the target drive. Note that every project is also at least 1 GB as well, so you will need more space on your computer (or an additional hard drive) for more projects you wish to create.

The launcher will start downloading the engine. It is about 7 GB, so it may take a while. Once finished, your screen should look something like this:

After the engine has installed, the Install Engine button will change to a Launch Engine button.

The Epic Games Launcher is the program that you need to start up the engine itself. It keeps a copy of all your projects and libraries in the Library tab.

As you learn more about working in UE4, you should check out some of the free library packages in the Library | Vault section. For that, click the Library item on the left-hand side and scroll down until you see Vault, underneath My Projects.

For the purpose of this book, we will always be using a C++ project:

 

Complete the previous recipe, Creating your first project in UE4. Once you have a project constructed, we can proceed with creating a level.

The MinimalDefault level and interface of Unreal Engine 4

You don't need to start with this starter stuff, however. If you don't want to build from it, you can delete it, or create a new level.

From here, you can select to create a level with a background sky (Default), or without a background sky (Empty Level).

By default, the Basic option is selected, which contains general geometry and other common features that are needed in Unreal. You can also add lights via the Modes tab by clicking on the Lights subtab on the left-hand side of the Modes tab. These can be added to a level by dragging and dropping as well.

To see the effects of changing one of the classes, we have to actually be using the class. Unreal automatically creates one of these classes for us by default (AChapter01_GameModeBase), so for this simple example, we will make use of it.

A game mode is a class that will contain the rules of your game type. 

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/GameModeBase.h"
#include "Chapter_01GameModeBase.generated.h"

/**
 * 
 */
UCLASS()
class CHAPTER_01_API AChapter_01GameModeBase : public AGameModeBase
{
 GENERATED_BODY()
public:
  void BeginPlay();

};

// Fill out your copyright notice in the Description page of Project Settings.

#include "Chapter_01GameModeBase.h"

void AChapter_01GameModeBase::BeginPlay()
{
  Super::BeginPlay();
}

This code currently doesn't do anything, but it gives us the ability to add changes to it later on in the future recipes of this chapter.

If all goes well, you should see a menu appear on the bottom-right of the screen, and after a period of time, you should see it say Compile Complete!:

It is also possible to compile your code in Visual Studio by right-clicking on the project from the Solution Explorer and selecting Build. Upon completion, when we go back to the Unreal editor, it should automatically load the changes that were made.

It is important for us to remember to compile our code any time we make changes to our code files. Otherwise, we will not be able to see those changes reflected in our project.

When coding, we may sometimes want to send some debug information out to the UE log window. This is possible using the UE_LOG macro. A macro is a fragment of code that has been given a name. Whenever the name is used in code, it is replaced by the contents of the macro at compile time. Log messages are an extremely important and convenient way to keep track of information in your program as you are developing it.

You should have a code file to complete this recipe. If this is your first time coding in Unreal, you should complete the previous recipe before continuing with this one.

UE_LOG(LogTemp, Warning, TEXT("Some warning message") );

For instance, if you wanted to add this to the script in the previous recipe, it may look like this:

#include "Chapter_01GameModeBase.h"

void AChapter_01GameModeBase::BeginPlay()
{
  Super::BeginPlay();

  // Basic UE_LOG message
  UE_LOG(LogTemp, Warning, TEXT("Some warning message") );
}

The UE_LOG macro accepts a minimum of three parameters:

Do not forget the TEXT() macro around your log message text, as it will convert the text into a format that is usable by UE_LOG. For those more familiar with coding, the TEXT() macro promotes the enclosed text to Unicode (it prepends an L) when the compiler is set to run with Unicode on. 

UE_LOG also accepts a variable number of arguments, just like printf() from the C programming language:

#include "Chapter_01GameModeBase.h"

void AChapter_01GameModeBase::BeginPlay()
{
  Super::BeginPlay();

  // Basic UE_LOG message

  UE_LOG(LogTemp, Warning, TEXT("Some warning message") );

// UE_LOG message with arguments
  int intVar = 5;
  float floatVar = 3.7f;
  FString fstringVar = "an fstring variable";
  UE_LOG(LogTemp, Warning, TEXT("Text, %d %f %s"), intVar, floatVar, *fstringVar );
}

There will be an asterisk * just before the FString variable when using UE_LOG to dereference the FString to a regular C-style TCHAR pointer. This means that it is converting the pointer into the actual value it is pointing at.

Don't forget to clear your log messages after you no longer need them from the source! Otherwise, your console may become bloated with messages and make it difficult to find things you are looking for.

For this, you should have an existing project into which you can enter some UE4 C++ code. Putting variables into a string is possible via printing. It may be counter intuitive to print into a string, but you can't just concatenate variables together and hope that they will automatically convert into strings, as in some languages, such as JavaScript.

In this recipe, we will see how to print in two different ways. First, we will be using FString::Printf():

FString name = "Tim"; 
int32 mana = 450; 
FString string = FString::Printf( TEXT( "Name = %s Mana = 
 %d" ), *name, mana );

Notice how the preceding code block uses the format specifiers precisely like the traditional printf function does. In the preceding example, we used %s to place a string in the formatted string, and %d to place an integer in the formatted string. Different format specifiers exist for different types of variables, and you should look them up on a site such as cppreference.com.

It is also possible to print a string using FString::Format().

FString name = "Tim"; 
int32 mana = 450; 
TArray< FStringFormatArg > args; 
args.Add( FStringFormatArg( name ) ); 
args.Add( FStringFormatArg( mana ) ); 
FString string = FString::Format( TEXT( "Name = {0} Mana = 
 {1}" ), args );

UE_LOG( LogTemp, Warning, TEXT( "Your string: %s" ), 
        *string );

With FString::Format(), instead of using correct format specifiers, we use simple integers and a TArray of FStringFormatArg instead. FstringFormatArg helps FString::Format() deduce the type of variable to put in the string. Refer to the following screenshot:

No matter which method you use, upon calling UE_LOG and you will get the same output.