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.
- Lua (5.1+) or LuaJIT (2.0+)
- GLFW (3.2+)
- OpenGL (3.3, ES3, or WebGL 2)
- OpenVR (1.0.9, for
lovr.headset
) - Oculus SDK (optional, 1.26+)
- PhysicsFS (3+)
- OpenAL (1.17+ recommended for HRTF support)
- msdfgen
- ODE (for
lovr.physics
) - Emscripten (optional, for compiling for web)
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:
- Version 26: Oculus Quest.
- Version 21: Oculus Quest and Oculus Go.
- Version 27: Pico Neo 2.
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:
- Set
CONFIG_PLATFORM
toandroid
. - Set
CONFIG_ANDROID_SDK
to the path to the Android SDK. - Set
CONFIG_ANDROID_VERSION
to the version of Android to use. Check thesdk/platforms
folder to see which Android versions are installed. - Set
CONFIG_ANDROID_BUILD_TOOLS_VERSION
to the build tools version. Check thesdk/build-tools
folder to see which versions are installed. - Set
CONFIG_HOST_TAG
to the type of computer you're using. Examples:windows-x86_64
for 64 bit Windows.darwin-x86_64
for 64 bit macOS.- Other: Check
ndk-bundle/prebuilt
folder to see a list of them.
- Set
CONFIG_ANDROID_KEYSTORE
to the path to the keystore file. See "Creating a Keystore" below for instructions on how to create a keystore. - Set
CONFIG_ANDROID_KEYSTORE_PASS
to the password to the keystore file. This can be used in multiple ways, described in "Creating a Keystore" below. - Optional: To use a custom Android manifest XML, set
CONFIG_ANDROID_MANIFEST
. - Optional: To embed assets in the APK (e.g. a project folder), set
CONFIG_ANDROID_ASSETS
.
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:
- Set
CMAKE_TOOLCHAIN_FILE
to the path toandroid.toolchain.cmake
. This is usually atndk-bundle/build/cmake/android.toolchain.cmake
inside the Android SDK. - Set
ANDROID_SDK
to the path to the Android SDK. - Set
ANDROID_ABI
toarm64-v8a
. - Set
ANDROID_NATIVE_API_LEVEL
to the Android version to use (e.g.26
). - Set
ANDROID_BUILD_TOOLS_VERSION
to one of the versions listed in thebuild-tools
folder. - Set
ANDROID_KEYSTORE
to the path to they keystore file. See "Creating a Keystore" below. - Set
ANDROID_KEYSTORE_PASS
to the keystore password. This can be used in multiple ways, described in "Creating a Keystore" below. - Optional: Set
ANDROID_MANIFEST
to use a custom Android manifest XML file. - Optional: Set
ANDROID_ASSETS
to include extra assets (e.g. a project folder) in the APK. - Windows: Make sure you add
-G "Unix Makefiles"
so it doesn't try to use Visual Studio.
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:
pass:<string>
will use<string>
as the password.env:<var>
will use the value of the<var>
environment variable.file:<file>
will use the contents of<file>
as the password.
Troubleshooting
- If you get "CMake no CMAKE_CXX_COMPILER found" on Windows, then install Visual Studio and create a blank C++ project, which will prompt you to install the compilers and tools necessary to compile LÖVR.
- On macOS, if you run into an error message about not being able to find OpenAL, make sure you've
added the proper OpenAL directory (usually something like
/usr/local/opt/openal-soft/lib/pkgconfig
) to yourPKG_CONFIG_PATH
environment variable. Installing openal-soft with brew will print out a message telling you how to do this.