Compiling LÖVR

Compiling the LÖVR code yourself lets you create a custom LÖVR build so you can add your own features or run it on other operating systems. Below is a guide for setting up all the dependencies and compiling the code on various types of systems.

Dependencies

LÖVR depends on the following libraries. They are included as submodules in the deps directory of the repository, so make sure you clone with the --recursive flag or run git submodule update --init in an existing repository.

Windows

From the lovr folder, run these commands to create a build folder and compile the project using CMake:

$ mkdir build
$ cd build
$ cmake ..
$ cmake --build .

The executable will then exist at /path/to/lovr/build/Debug/lovr.exe. A LÖVR project (a folder containing a main.lua script) can then be dropped onto lovr.exe to run it, or it can be run via the command line as lovr.exe path/to/project.

macOS

Install the dependencies using your package manager of choice:

$ brew install glfw3 luajit physfs openal-soft ode libccd

Next, build using CMake, as above:

$ mkdir build
$ cd build
$ cmake ..
$ cmake --build .

The lovr executable should exist in lovr/build now. It's recommended to set up an alias or symlink so that this executable can be found in your PATH environment variable. Once that's done, you can run a project like this:

$ lovr /path/to/myGame

You may need to set the PKG_CONFIG_PATH environment variable for OpenAL to be located properly. If you run into this, see Troubleshooting below for more info.

Linux

First, install the dependencies using your package manager of choice.

Arch Linux

$ pacman -S glfw-x11 luajit physfs openal ode

Debian/Ubuntu

$ sudo apt install build-essential cmake xorg-dev libglfw3-dev libluajit-5.1-dev libphysfs-dev libopenal-dev libode-dev libccd-dev libenet-dev

Then, build with CMake:

$ mkdir build
$ cd build
$ cmake ..
$ cmake --build .

On Linux, LÖVR needs to run within the Steam Runtime. To do this, first install Steam. Next, install the Steam udev rules. Then, run LÖVR within the Steam runtime:

$ ~/.steam/steam/ubuntu12_32/steam-runtime/run.sh lovr

If you receive errors related to libstdc++, set the LD_PRELOAD environment variable when running the command:

$ LD_PRELOAD='/usr/$LIB/libstdc++.so.6 /usr/$LIB/libgcc_s.so.1' ~/.steam/steam/ubuntu12_32/steam-runtime/run.sh lovr

WebXR

First, install the Emscripten SDK.

Unix:

$ mkdir build
$ cd build
$ emcmake cmake ..
$ emmake make -j2

Windows (from a Visual Studio Command Prompt, make sure the Emscripten SDK is on PATH):

$ mkdir build
$ cd build
$ emcmake cmake -G "NMake Makefiles" ..
$ emmake nmake

The above commands will output lovr.js, lovr.wasm, and lovr.html. The easiest way to run LÖVR from here is to use emrun:

$ emrun --browser firefox lovr.html

To add a project, create a .zip of its contents and serve it alongside the HTML and JS files. The following JS can be added to the page to download the zip file, add it to the emscripten virtual filesystem, and add it as a command line argument:

var filename = 'game.zip';
var url = '/game.zip';
Module.arguments.push(filename);
Module.preRun.push(function() {
  Module.FS_createPreloadedFile('/', filename, url, true, false);
});

See lovr.html (or src/resources/lovr.html) for a full example page, including a button that can be used to enter/exit immersive mode.

Android

Here be dragons.

First, make sure the Java JDK is installed (version 8 is known to work).

Then, the Android SDK and NDK need to be installed. The SDK version to install depends on the devices being targeted:

The Android command line tools can be found on the Android website or installed using a package manager. The command line tools contain a tool named sdkmanager that can be used to install various versions of Android, the Android build tools, and the NDK.

Android Studio isn't required, but can be used to install the SDK, NDK, and Java as well.

Note where the SDK is installed. Some paths in the SDK will need to be specified.

CMake or tup can be used to build an APK that can be installed on an Android device.

When building for Oculus Android devices, download the latest Oculus Mobile SDK and copy the VrApi folder from there into deps.

tup

When using tup, third-party dependencies need to be built with CMake. Follow the CMake instructions below, but add -DLOVR_BUILD_EXE=OFF to only build the LÖVR dependencies.

Next, make sure you have a tup.config file in the repository root. A sample config file can be found at config/default. Some android-specific configuration needs to be filled in there:

Once all of this is set up, run tup init if tup hasn't been initialized yet. Then run

$ tup

to build the apk.

CMake

The following CMake variables need to be set, either using the CMake GUI or by using -D flags on the command line:

The usual CMake incantation with all of the above variables set up should produce lovr.apk:

$ cmake ..
$ cmake --build .

Installing the APK

To install the APK, an Android device needs to be connected. Run

$ adb devices

to ensure that a device is connected, then run

$ adb install lovr.apk

To install the apk. The -r flag can be used to overwrite an existing apk.

Adding Project Code

To build an apk that runs a LÖVR project, pass the folder path as the ANDROID_ASSETS option to either CMake or tup. This will run the LÖVR project when the apk starts, similar to how things work when fusing a zip to an exe on desktop systems.

Using a Custom Android Manifest

Although LÖVR provides a default AndroidManifest.xml, you can also use your own by passing its path as the ANDROID_MANIFEST option to either CMake or tup. This can be used to request extra permissions, change the package ID or app name, etc.

Any file named AndroidManifest*.xml will be ignored in LÖVR's git repository.

Creating a Keystore

A keystore file needs to be generated, which is used to sign the APK after it's built.

To generate a keystore, use Java's keytool tool:

$ keytool -genkey -keystore <name>.keystore -alias <name> -keyalg RSA -keysize 2048 -validity 10000

When specifying the password for the keystore, it can be done in multiple ways:

Troubleshooting