Drawing pause Screen as a layer over the play screen-LibGdx

问题

In my LibGdx Game I created pause functionality.While playing game,If I press pause button,a separate screen with resume button displays.

What actually I want to do is that the pause screen should appear above the game play screen like a layer.

Like the screen shot of a game below:

I could only make a new pause screen in my game with separate bg and all. I want to display the paused game as it is.Above that I can draw graphics for resume button,box etc exactly like the screen shot.

How can I acheive this layer like display of pause screen?

回答1:

Inside Gamescreen, you're using stage for UI(buttons to navigate). I am pretty sure you're doing like this.

private uiStage;
private boolean isPause;
private Group pauseGroup; 

public void render(){

    if(!isPause) UpdateGame();    
    DrawGame();         

    uiStage.act();
    uiStage.draw();
}

Create a Group whenever you want to pause your game and remove that group when you want to resume your game. You can also crate your Group once and add all pause UI in show() method. Add that group to stage when you want to show pause and remove when you resume your game.

public void pauseGame(){

   isPause = true;
   pauseGroup = new Group;
   Image semiTransparentBG= ......
   // setSize(Size of screen) and make it semi transparent.
   pauseGroup.addActor(semiTransparentBG);

   //crate all other pause UI buttons with listener and add to pauseGroup

   stage.addActor(pauseGroup);

}

public void resumeGame(){

    if(isPause){
      isPause=false;
      pauseGroup.remove();
    }  
}

回答2:

Short answer: yes, you can. First let your pause screen extend the Stage class instead of the Screen class. Then try calling the draw of the pause screen after the draw of the game. Something like this:

public void render(){
    UpdateGame();
    pause_screen.act();

    DrawGame();
    pause_screen.draw();
}

Stop the game updates when the pause screen is open. Off course this is over simplified, but you can look in to it.

来源：https://stackoverflow.com/questions/42578795/drawing-pause-screen-as-a-layer-over-the-play-screen-libgdx

标签

user-interface

libgdx