简体   繁体   中英

libgdx and Box2d collision optimisation

I am new to Libgdx and I am a little confused on the best way to do collision/movement. And it is bothering me a lot and I cant seem to move on from there unless I know I am not doing it the wrong way.

This is my current classes that I am using.

public class Play extends GameState{
    public Play(GameStateManager {
        super(gsm);
        world = new World(new Vector2(0, -9.81f), true);
        b2dr = new Box2DDebugRenderer();

        cl = new MyContactListener();
        world.setContactListener(cl);

        createPlayer();

        b2dCam = new OrthographicCamera();
        b2dCam.setToOrtho(false, Game.V_WIDTH / PPM, Game.V_HEIGHT / PPM);
    }

    public void update(float dt) {

        handleInput();

        player.update(Gdx.graphics.getDeltaTime());

        world.step(dt, 6, 2);
    }

     public void render() {
        Gdx.gl20.glClear(GL20.GL_COLOR_BUFFER_BIT);

        cam.update();

        tmr.setView(cam);
        tmr.render();

        sb.setProjectionMatrix(cam.combined);
        player.render(sb);

        b2dr.render(world, b2dCam.combined);
    }



    public void handleInput() {
        if(MyInput.isPressed(MyInput.BUTTON1)){
            if(cl.isPlayerOnGround()){
                player.getBody().applyForceToCenter(0, 150, true);
            }
        }



        if(MyInput.isDown(MyInput.BUTTON2)){
                if(cl.isPlayerOnGround())
                 player.setVelocity(new Vector2(1, player.getVelocity().y));
                else if(Math.abs(player.getVelocity().y) < .3)
                    player.getBody().applyLinearImpulse(.15f, 0, player.getPosition().x, player.getPosition().y, true);
        }else{
            if(MyInput.isDown(MyInput.BUTTON3)){
                    if(cl.isPlayerOnGround()) {
                        player.setVelocity(new Vector2(-1, player.getVelocity().y));
                    }else if(Math.abs(player.getVelocity().y) < .3){
                            player.getBody().applyLinearImpulse(-.15f, 0, player.getPosition().x, player.getPosition().y, true);
                    }
            }else{
                if(cl.isPlayerOnGround())
                    player.setVelocity(new Vector2(0, player.getVelocity().y));
            }
        }
    }
}

My Player class extends this

public class AnimationHandler {
protected Body body;
protected Animation animation;
protected float width;
protected float height;

private float time;



public AnimationHandler(Body body){
    this.body = body;
    animation = new Animation(1/12f);
}

public void setAnimation(TextureRegion[] region, float delay){
    animation = new Animation(delay, region);
    width = region[0].getRegionWidth();
    height = region[0].getRegionHeight();
}

public void render(SpriteBatch sb){
    time += Gdx.graphics.getDeltaTime();

    sb.begin();
    sb.draw(
            animation.getKeyFrame(time, true),
            body.getPosition().x * B2DVars.PPM - width / 2,
            body.getPosition().y * B2DVars.PPM - width / 2
    );
    sb.end();
}

public Body getBody() {
    return body;
}

So the main thing I wanted to take a look at is in The first class (Play) method handleInput(). I am currently using player.setVelocity() as movement. What this does for me is it automatically does collision handling for walking left and right. And it works pretty well I admit. But I want someones opinion on this, I keep having a feeling there are flaws in the way I am doing it. One flaw I was thinking about is if I have a platformer type game and want to jump up through a platform but land on it when I come back down I am not sure that is possible.. Because it is doing the collision itself instead of manually doing it. Any thoughts? Any input would be really appreciated, I am new to game programming and I want to be doing things the best way possible.

I'd say Box2D is very well suited for making a platformer (I know from my own experience). A great starting point is described here: http://www.badlogicgames.com/wordpress/?p=2017

Also, try to prevent creating unnecessary new objects to reduce gc pressure: player.setVelocity(new Vector2(1, player.getVelocity().y));

This creates a new Vector2 every time and should be avoided because it generates garbage. In this case body.setLinearVelocity(vx, vy); would be preferable

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM