Next up, you need to import your project into your IDE.
Importing the Project
If you have just generated the project in gdx-liftoff, you may click the option “Open in IntelliJ Idea” to get started right away. Otherwise, continue with the following steps:
-
In IntelliJ IDEA or Android Studio, you can choose to open the
build.gradlefile and select “Open as Project” to get started.In Eclipse, choose
File -> Import... -> Gradle -> Existing Gradle Project(make sure that your freshly generated project is not located inside of your workspace).In NetBeans it is
File -> Open Project. -
You may need to refresh the Gradle project after the initial import if some dependencies weren’t downloaded yet.
In IntelliJ IDEA/Android Studio, the
Reimport all Gradle projectsbutton is a pair of circling arrows at the top left in the Gradle tool window, which can be opened withView -> Tool Windows -> Gradle.In Eclipse right-click on your project
Gradle -> Refresh Gradle Project.
Getting it Running
If you want to execute your freshly imported project, you have to follow different steps, depending on your IDE and the platform you are targeting.
Desktop
In IDEA/Android Studio:
- Extend the Gradle tab on the right sight of your window:
-
Expand the tasks of your project and then select: lwjgl3 -> other -> run.
In Android Studio 4.2, tasks are no longer shown by default. Go to
Settings -> Experimentaland uncheckDo not build Gradle task list during Gradle sync. Then sync the project viaFile -> Sync Project with Gradle Files
Alternatively, you can create a run configuration:
- Right-click your Lwjgl3Launcher class
- Select ‘Run Lwjgl3Launcher.main()’. This should fail with missing assets, because we need to hook up the assets folder first.
- Open up Run Configurations
-
Edit the Run Configuration that was just created by running the lwjgl3 project and set the working directory to point to your
assetsfolder
On macOS, LWJGL3 projects require one extra step: Either add the (experimental)
com.badlogicgames.gdx:gdx-lwjgl3-glfw-awt-macosdependency to your lwjgl3 project, or, in your Run Configuration, set the VM Options to-XstartOnFirstThread. Additional information can be found here. - Run your application using the run button
In Eclipse:
- Right-click your lwjgl3 project -> Run as -> Run Configurations…
- On the right side, select Java Application:
- At the top left, click the icon to create a new run configuration:
- As Main class select your
Lwjgl3Launcherclass - After that, click on the Arguments tab
-
At the bottom, under ‘Working directory’ select ‘Other’ -> Workspace…
On macOS, LWJGL3 projects require one extra step: Either add the (experimental)
com.badlogicgames.gdx:gdx-lwjgl3-glfw-awt-macosdependency to your lwjgl3 project, or, in your Run Configuration, set the VM Options to-XstartOnFirstThread. Additional information can be found here. - Then select your asset folder located in
assets
In NetBeans:
Right-click the lwjgl3 project -> Run
Android
- IDEA/Android Studio: Right-click AndroidLauncher -> Run AndroidLauncher
- Eclipse: Right-click Android project -> Run As -> AndroidApplication
- NetBeans: Right-click Android project -> Run As -> AndroidApplication
iOS
In IDEA/Android Studio
- Open Run/Debug Configurations
-
Create a new run configuration for a RoboVM iOS application
-
Select the provisioning profile and simulator/device target
Note: arm64 simulators are not working by default. Either use x86_64 or use the MetalANGLE RoboVM backend instead (“com.badlogicgames.gdx:gdx-backend-robovm-metalangle:$gdxVersion”)
- Run the created run configuration
For more information on using and configuring the RoboVM IntelliJ IDEA plugin please see the documentation.
In Eclipse
- Right-click the iOS RoboVM project > Run As > RoboVM runner of your choice
For more information on using and configuring the RoboVM IntelliJ IDEA plugin please see the documentation.
HTML
HTML is best suited to be run on command line. You are welcome to manually setup GWT in the IDE of your choice if you are familiar with it, but the recommended way is to drop down to terminal or command prompt.
The HTML target can be run in Super Dev mode, which allows you to recompile on the fly, and debug your application in browser.
To do so, open up your favourite shell or terminal, change directory to the project directory and invoke the respective gradle task:
./gradlew html:superDev
On Unix: If you get a permission denied error, set the execution flag on the gradlew file: chmod +x gradlew
You should see lots of text wizzing by, and if all goes well you should see the following line at the end:
You can then go to http://localhost:8080/index.html, to see your application running, with a recompile button.
For further info on configuring and debugging with SuperDev check the GWT documentation.
Command Line
All the targets can be run and deployed to via the command line interface.
Desktop:
./gradlew lwjgl3:run
Android:
./gradlew android:installDebug android:run
The ANDROID_HOME environment variable needs to be pointing to a valid android SDK before you can do any command line wizardry for Android. On Windows, use: set ANDROID_HOME=C:/Path/To/Your/Android/Sdk; on Linux and macOS: export ANDROID_HOME=/Path/To/Your/Android/Sdk. Alternatively you can create a file called “local.properties” with the following content: sdk.dir /Path/To/Your/Android/Sdk.
iOS:
./gradlew ios:launchIPhoneSimulator
HTML:
./gradlew html:superDev
Then go to http://localhost:8080/index.html.
Gradle tasks are failing?
If whenever you invoke Gradle, the build or refresh fails to get more information, run the same command again and add the --debug parameter to the command, e.g.:
./gradlew lwjgl3:run --debug
This will provide you with a stacktrace and give you a better idea of why gradle is failing.
What to do next?
Now that you’re done with the set-up, you can get to do some real coding. Take a look at our post A Simple Game for a step-by-step guide.