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.
LÖVR is currently known to work with (and optimized for)
Other systems and hardware may work, but are not frequently tested.
LÖVR uses 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 --recursive
in an existing repository.
LÖVR requires a C compiler that supports C11. GCC 4.9, clang 3.1, and Windows SDK 2104 support C11.
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
.
Build using CMake, as above:
$ mkdir build
$ cd build
$ cmake ..
$ cmake --build .
The lovr executable should exist in lovr/build/bin
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
:::note
You can set the LOVR_BUILD_BUNDLE
CMake variable to ON
to build a .app instead of a plain
executable.
:::
LÖVR requires MoltenVK 1.3.268 or higher. The easiest way to get MoltenVK is to install the Vulkan SDK from LunarG. Be sure to leave the "global install" checkbox enabled while installing so LÖVR is able to find the Vulkan library.
Prebuilt binaries include MoltenVK in the .app bundle, so installing the Vulkan SDK is optional when using one of those builds.
First, install a C compiler, CMake, and other dependencies:
$ sudo apt install make cmake xorg-dev libcurl4-openssl-dev libxcb-glx0-dev libx11-xcb-dev python3-minimal
$ sudo dnf install cmake clang libX11-devel libXrandr-devel libXinerama-devel libXcursor-devel libXi-devel libcurl-devel
Then, compile using CMake:
$ mkdir build
$ cd build
$ cmake ..
$ cmake --build .
LÖVR can use either SteamVR or monado as the VR runtime on Linux.
To use LÖVR with SteamVR 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:
$ ~/.local/share/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
To compile an Android APK with CMake, follow the steps below.
You will need to compile on a macOS or Linux system. Compiling LÖVR APKs on Windows does not currently work (unless all steps are performed in Windows Subsystem for Linux).
First, make sure the Java JDK is installed (version 17 is known to work).
Then, install the Android SDK (29) and NDK (21.4.7075529).
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:
$ cmdline-tools/bin/sdkmanager --sdk_root=/path/to/android/sdk "build-tools;34.0.0" "cmake;3.22.1" "ndk;21.4.7075529" "platform-tools" "platforms;android-29"
The SDK will be installed to the chosen sdk_root
path. To reduce the SDK size, the emulator
package can be safely uninstalled:
$ cmdline-tools/bin/sdkmanager --sdk_root=/path/to/android/sdk --uninstall emulator
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.
Finally, compiling a LÖVR APK requires a copy of the glslangValidator
tool installed on the
system. Most package managers will offer this as part of a "glslang" or "glslang-tools" package.
The following CMake variables need to be set, either using the CMake GUI or by using -D
flags on
the command line:
CMAKE_TOOLCHAIN_FILE
to the path to android.toolchain.cmake
. This is usually at
ndk-bundle/build/cmake/android.toolchain.cmake
inside the Android SDK.ANDROID_SDK
to the path to the Android SDK.ANDROID_ABI
to arm64-v8a
.ANDROID_NATIVE_API_LEVEL
to the Android version to use (e.g. 29
).ANDROID_BUILD_TOOLS_VERSION
to one of the versions listed in the build-tools
folder.ANDROID_KEYSTORE
to the path to they keystore file. See "Creating a Keystore" below.ANDROID_KEYSTORE_PASS
to the keystore password. This can be used in multiple ways,
described in Creating a Keystore below.ANDROID_MANIFEST
to use a custom Android manifest XML file.ANDROID_ASSETS
to include extra assets (e.g. a project folder) in the APK.-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
:
$ mkdir build
$ cd build
$ cmake \
-D CMAKE_TOOLCHAIN_FILE=/path/to/ndk/build/cmake/android.toolchain.cmake \
-D ANDROID_SDK=/path/to/android \
-D ANDROID_ABI=arm64-v8a \
-D ANDROID_NATIVE_API_LEVEL=29 \
-D ANDROID_BUILD_TOOLS_VERSION=34.0.0 \
-D ANDROID_KEYSTORE=/path/to/test.keystore \
-D ANDROID_KEYSTORE_PASS=pass:hunter2 \
..
$ cmake --build .
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.
To build an APK that runs a LÖVR project instead of the splash screen, add an ANDROID_ASSETS
CMake
variable with the path to the project folder. The project will be included in the assets
folder
of the APK, and LÖVR will run that project when the APK starts.
:::warning By default the Android packager ignores directories that begin with underscores. :::
Although LÖVR provides a default AndroidManifest.xml
, you can also use your own by passing its
path as the ANDROID_MANIFEST
option to CMake. This can be used to request extra permissions,
change the package ID or app name, etc.
LÖVR extracts the package name from the AndroidManifest.xml
file (org.lovr.app
by default). To
use a different package id, edit etc/AndroidManifest.xml
, or set the ANDROID_MANIFEST
CMake
variable to set a custom manifest with a different package id.
APKs must be signed to work properly. First, generate a keystore file using Java's keytool
tool:
$ keytool -genkey -keystore <name>.keystore -alias <name> -keyalg RSA -keysize 2048 -validity 10000
The ANDROID_KEYSTORE
CMake variable should be set to the path to the keystore file, and the
ANDROID_KEYSTORE_PASS
variable contains the password used when creating the keystore. The password
can take the following forms:
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.The lovr-docker-builder project provides an approach based on Docker to build Linux and Android applications, wihout instaling packages locally
To use it, you'll need to install Docker.
Then follow the instruction in the repo. Refer to them for any issues with it, as it's an indipendent project
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.<stdalign.h>
header missing on Windows, then the compiler does
not support C11, and a newer version of the Windows SDK (at least 2104) needs to be installed.