libGDX in sbt (2021)
libGDX is/was the bestest way to do OpenGL in Java/Scala on Desktop/Android.
background
It can do a bunch of platforms but the biggest appeal to me was that it really-really did work on both Windows and Android. Lots of libraries were touted as “JVM and Android” and then … only ran on Android … which isn’t using the JVM.
libGDX is pretty low-level, but, does have conventions to reduce a lot of the tedium. It doesn’t do the same amount of stuff as Unreal or Unity does for you - so you will need to reinvent a lot of wheels.
I wanted to do something (I forget what) with image processing in GLSL and tried using a libGDX window to do it. Getting it up and running was a task/chore in 2021 so I wrote these notes.1
.sbt file
You’ll need a .sbt file … like this?
resolvers += Resolver.jcenterRepo
scalaVersion := "2.12.13"
// add libGDX stuff
val gdxVersion = "1.9.3"
libraryDependencies ++=
Seq(
"com.badlogicgames.gdx" % "gdx" % gdxVersion,
"com.badlogicgames.gdx" % "gdx-backend-lwjgl" % gdxVersion,
"com.badlogicgames.gdx" % "gdx-platform" % gdxVersion classifier "natives-desktop",
)main task
Here is an example class/function. It opens a window, runs your task, then exits.
package peterlavalle.mimic
import com.badlogic.gdx.ApplicationAdapter
object OneRun {
/**
* runs a libGDX app then exits after one frame ... likely for gpGPU reasons
*
* @param action to run on the frame
*/
def apply()(action: => Unit): Unit = {
object lock {
var done = false
}
class Application extends ApplicationAdapter {
import com.badlogic.gdx.Gdx
override def render(): Unit = {
action
Gdx.app.exit()
}
override def dispose(): Unit = {
lock.synchronized {
lock.done = true
lock.notifyAll()
}
}
}
import com.badlogic.gdx.backends.lwjgl.{LwjglApplication, LwjglApplicationConfiguration}
lock.synchronized {
val config = new LwjglApplicationConfiguration()
new LwjglApplication(new Application(), config)
while (!lock.done)
lock.wait()
}
}
}- Which I’m posting today in 2022 [return]
