如何在 libgdx 中创建非常简单的暂停/恢复游戏

Question

i am newbie for libgdx, How to create very simple pause/resume game in libgdx??

I'm trying to implement simple game using libgdx. I have want to create pause the game but don't know how to pause and resume game based on user input.Kindly suggest idea as well as some practical code to implement the same.I am using simple game code demonstrated in libgdx library. Thank you.

public class MyGdxGame extends ApplicationAdapter {
    SpriteBatch batch;
    Texture img;
    float x;
    float y;

@Override
public void create () {
    batch = new SpriteBatch();
    img = new Texture("badlogic.jpg");
}

@Override
public void render () {
    Gdx.gl.glClearColor(1, 0, 0, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

    x= x+4;

    if(Gdx.input.isKeyPressed(Input.Keys.P)){
      // pause
        
    }

    batch.begin();
    batch.draw(img, x, y);
    batch.end();
}

@Override
public void dispose () {
    batch.dispose();
    img.dispose();
}

}

Press P key to press the game

if(Gdx.input.isKeyPressed(Input.Keys.P)){
      // if(game.pause()){
             game.resume();
          }else{
           game.pause();
             }

    }

any idea??? thanks

Answer 1

Your render method is called repeatable and what "paused" means is up to you. You have to implement your logic that handles "paused" state because that doesn't mean anything to libGDX.

If you want everything to freeze when game is paused but still to be drawn best way is (IMHO) to fully separate drawing from calculating (movements and stuff). So ie when your render method is called you will call your drawing method once (to draw the graphics) but you will also calculate how many times your calculation method should be call (to have same game speed independently on frame rate) and call it that many times.

Then when your game is paused you will just skip calling your calculation method and call only drawing method. So nothing will move and until you end your pause the same graphics will be drawn.

And to keep paused state you can have some boolean variable. Every time p key is pressed you should invert it, like:

if(Gdx.input.isKeyPressed(Input.Keys.P)){
    paused = !paused;
}

or something (as @Tenfour04 suggested).