how to add button to an ApplicationAdapter in libgdx?

Question

I am using libgdx.

So far I have two cylinders and am able to rotate them

My goal is to add a button to this view, so I am able to go to other view.

Currently I have camera, cameracontroller, environment, and two models.

example:

code I wrote so far:

public class FirstOfTheAndroid extends ApplicationAdapter {
@Override
public void create() {

    // adding a new Renderer
    modelBatch = new ModelBatch();

    // adding a new environment
    environment = new Environment();
    environment.set(new ColorAttribute(ColorAttribute.AmbientLight, 0.4f, 0.4f, 0.4f, 1f));
    environment.add(new DirectionalLight().set(0.8f, 0.8f, 0.8f, -1f, -0.8f, -0.2f));

    // adding a camera
    cam = new PerspectiveCamera(67, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
    cam.position.set(10f, 10f, 10f);
    cam.lookAt(0, 0, 0);
    cam.near = 1f;
    cam.far = 300f;
    cam.update();

    // adding a new model
    ModelBuilder modelBuilder = new ModelBuilder();
    model = modelBuilder.createCylinder(4f, 6f, 4f, 16,
            new Material(
                    ColorAttribute.createDiffuse(Color.GOLD),
                    ColorAttribute.createSpecular(1, 1, 1, 1),
                    FloatAttribute.createShininess(8f)),
            VertexAttributes.Usage.Position
                    | VertexAttributes.Usage.Normal
                    | VertexAttributes.Usage.TextureCoordinates);
    model2 = modelBuilder.createCylinder(5f, 5f, 5f, 16,
            new Material(
                    ColorAttribute.createDiffuse(Color.GOLD),
                    ColorAttribute.createSpecular(1, 1, 1, 1),
                    FloatAttribute.createShininess(8f)),
            VertexAttributes.Usage.Position
                    | VertexAttributes.Usage.Normal
                    | VertexAttributes.Usage.TextureCoordinates);

    instance = new ModelInstance(model);
    instance2 = new ModelInstance(model2);

    // adding a camera control
    camController = new CameraInputController(cam);
    Gdx.input.setInputProcessor(camController);
}

@Override
public void render() {
    Gdx.gl.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
    Gdx.gl.glClearColor(84/255f, 84/255f, 84/255f, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);

    modelBatch.begin(cam);
    modelBatch.render(instance, environment);
    modelBatch.render(instance2, environment);
    modelBatch.end();

    camController.update();
}

}

Answer 1

As a commenter mentioned, Scene2D is LibGDX's library for this.

I am rolling my own button system and just figured out how to do it well, here's the link: https://stackoverflow.com/a/43792814/1159741

Finally, here's a simple method - brute force, only effective if you have just a few buttons in the whole game.

Create a handleInput() method in your game class. In render():

if(Gdx.input.justTouched()) handleInput();

and handleInput():

    Vector3 touchCoords = new Vector3(Gdx.input.getX(), Gdx.input.getY(), 0); // use a Vector2 if you switch from Camera to Viewport
    camera.unproject(touchCoords); // converts screen coordinates to game coordinates
    if(touchCoords.x > [button left side x] &&
       touchCoords.x < [button right side x] &&
       touchCoords.y > [button bottom y] &&
       touchCoords.y < [button top y])
        // do something here
    else if(... check coordinates for the other button)
         // then do this
    // and so on for additional buttons