Introduction

This is the first tutorial in a two (or maybe three) part series that will explain how to integrate libraries not built by UBT into your UE4 games or plugins. This tutorial will cover building of static libraries in VS2013, but most of this will also apply when building dynamic libraries.

We’re going to build the pugixml library, a small and lightweight XML processing library written in C++. I’ve chosen this library because it doesn’t have any dependencies, only consists of three source files, and is easy to configure, so we can focus on the details that are specifically relevant to Unreal Engine 4. The final VS2013 project is available on GitHub.

Configure pugixml

The library can be configured by editing pugiconfig.hpp.

Unreal Engine 4 uses the Unicode character set by default (characters are represented by wchar_t instead of char), so lets enable Unicode support in pugixml:

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#ifdef UNICODE
// Uncomment this to enable wchar_t mode
#define PUGIXML_WCHAR_MODE
#endif // UNICODE

Usage of the STL is frowned upon in Unreal Engine 4 code because it comes with its own set of standard-for-ue4 classes you should use instead. Third party libraries can still use the STL if needed. pugixml has the ability to use the STL for strings and streams, but it can also work quite happily without it, so lets remove the STL dependency:

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// Uncomment this to disable STL
#define PUGIXML_NO_STL

By default UBT will build projects with C++ exceptions disabled, it’s best to keep this setting consistent across all the libraries that are linked into a game project. We can prevent pugixml from throwing C++ exceptions like so:

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// Uncomment this to disable exceptions
#define PUGIXML_NO_EXCEPTIONS

Project Properties

Platforms

We’ll need to create 32-bit and 64-bit versions of the library. The 32-bit version will be used in shipping builds (by default), and the 64-bit version will be used in development editor builds. VS2013 sets up a 32-bit platform by default, so we just need to add the 64-bit platform to the project. To do so:

  1. Right-click on the project in the VS2013 Solution Explorer, select Properties from the context menu, and open the Configuration Manager dialog: Press on the Configuration Manager button on the Property Pages window.
  2. Add a new platform: Select New from the Active solution platform drop-down.
  3. Select x64 from the drop-down, and press OK: Select x64 from the first drop-down.

General Properties

The naming convention and directory structure you use for the library binaries is entirely up to you, however, future tutorials may assume you’ve set things up as described here.

  1. Select All Configurations from the Configuration drop-down.
  2. Select Win32 from the Platform drop-down.
  3. Set the following properties on the Configuration Properties/General page as indicated:
    • Output Directory: $(SolutionDir)Build\\
    • Intermediate Directory: $(SolutionDir)Obj\\Win32\\$(Configuration)\\
    • Target Name: $(ProjectName)-Win32-$(Configuration)
  4. Press the Apply button.
  5. Select x64 from the Platform drop-down.
  6. Set the following properties under the Configuration Properties/General section as indicated:
    • Output Directory: $(SolutionDir)Build\\
    • Intermediate Directory: $(SolutionDir)Obj\\Win64\\$(Configuration)\\
    • Target Name: $(ProjectName)-Win64-$(Configuration)
  7. Press the Apply button.
  8. Select All Platforms from the Platform drop-down.
  9. Ensure that the Character Set property is set to Use Unicode Character Set.

C/C++ Properties

  1. Ensure that All Configurations and All Platforms are still selected.
  2. On the Configuration Properties/Code Generation page set Enable C++ Exceptions to No, and press the Apply button.
  3. On the Configuration Properties/Language page set Enable Run-Time Type Information to No, and press the Apply button.
  4. Return to the Configuration Properties/Code Generation page.
  5. Select the Debug configuration, and ensure Runtime Library is set to Multi-threaded Debug DLL (/MDd).
  6. Select the Release configuration, and ensure Runtime Library is set to Multi-threaded DLL (/MD)

Build

You can now quickly build all four variants of the library by selecting Build->Batch Build... from the main menu in VS2013.

Tick Build for all Solution Configurations and press the Build button.