How to split a screen in half using LibGDX without scaling?

Question

I am currently working on a racing game with libGDX and I need to split the screen in half for a two-players mode. (Player 1 in first half and Player 2 in second half).

I already have Camera1 that will follow Player 1's car, and Camera2 that will follow Player 2's car.

Basically, I want the first half to show Player 1's car and the second half to show Player 2's car.

I have been searching for a while online for a way to split screens with LibGDX and found how to split the screen in two with this code:

/*Left Half*/
Gdx.gl.glViewport( 0,0,Gdx.graphics.getWidth()/2,Gdx.graphics.getHeight() );

/*Right Half*/
Gdx.gl.glViewport(Gdx.graphics.getWidth()/2,0,Gdx.graphics.getWidth()/2,Gdx.graphics.getHeight() );

However, it squeezes the screen into the right half, which is not what I want.

Is there a way to split the screen without squeezing it?

Answer 1

I would suggest having a look at this page and using a viewport to manage both cameras. Since you don't want scaling a ScreenViewport would be the way to go.

https://github.com/libgdx/libgdx/wiki/Viewports

// These would be the cameras you have set up which are following the players
Camera playerOneCamera;
Camera playerTwoCamera;

ScreenViewport playerOneViewport = new ScreenViewport(playerOneCamera);
ScreenViewport playerTwoViewport = new ScreenViewport(playerTwoCamera);

Each time the window is resized you would update both viewports with new dimensions and offsets. To split the screen vertically you would do the following:

public void resize(int width, int height){
    playerOneViewport.update(width / 2, height);
    playerTwoViewport.update(width / 2, height);
    playerTwoViewport.setScreenX(width / 2);
}

Then each draw call you perform two renderings, one using the first cameras projection and another using the second cameras projection.

public void render(){
    // Set batch to use first players camera
    batch.setProjectionMatrix(playerOneCamera.combined);
    batch.begin();
    // Render what is required
    batch.end();

    // Set batch to use second players camera
    batch.setProjectionMatrix(playerTwoCamera.combined);
    batch.begin();
    // Render what is required
    batch.end();
}