CODEWITHSUNDEEP
javalibgdx
User765876
User765876

Reputation: 135

Making sprites move in oppsite direction of vector

I have a sprite that moves from the bottom left of the screen to the top right. What I want to know is how would i make it turn around and go in the opposite direction, and continue this loop.

I tried negating the direction of the vector but that doesnt work.

This what i have right now:

public void create() {
    // Game Initialization  
    v = new Vector2(Gdx.graphics.getWidth() - 0, Gdx.graphics.getHeight() - 0); 
    v.nor();
    v.scl(100);

    spriteBatch = new SpriteBatch(); 
    bug = new Sprite(new Texture("EnemyBug.png"));
    bug.setSize(50, 85);
    bug.setOrigin(0,0);//Gdx.graphics.getHeight() / 5, Gdx.graphics.getHeight() / 5);
    bug.setPosition(1,1);//Gdx.graphics.getWidth() - 50, Gdx.graphics.getHeight() - 50);
    bug.rotate(v.angle());

    rotDeg = 5;
}

@Override
public void render() {
    // Game Loop

    Gdx.gl.glClearColor(0.7f, 0.7f, 0.2f, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
    spriteBatch.begin();        

    if(bug.getX() >= (int)(Gdx.graphics.getWidth() - 100) && bug.getY() >= (int)(Gdx.graphics.getHeight() - 100)){
        turn = !turn;
    }
    else if(bug.getX() <= 50 && bug.getY() <= 50){
        turn = !turn;
    }


    if(!turn){          
        bug.translate(v.x * Gdx.graphics.getDeltaTime(), v.y * Gdx.graphics.getDeltaTime());
    }
    else{
        bug.translate(-(v.x * Gdx.graphics.getDeltaTime()), -(v.y * Gdx.graphics.getDeltaTime()));
    }

    bug.translate(v.x * Gdx.graphics.getDeltaTime(), v.y * Gdx.graphics.getDeltaTime());
    bug.draw(spriteBatch);
    spriteBatch.end();
}

Upvotes: 0

Views: 292

Answers (1)

MadEqua
MadEqua

Reputation: 1142

You are translating the sprite twice per frame:

if(!turn){          
        bug.translate(v.x * Gdx.graphics.getDeltaTime(), v.y * Gdx.graphics.getDeltaTime());
    }
    else{
        bug.translate(-(v.x * Gdx.graphics.getDeltaTime()), -(v.y * Gdx.graphics.getDeltaTime()));
    }

    //REMOVE THIS LINE
    bug.translate(v.x * Gdx.graphics.getDeltaTime(), v.y * Gdx.graphics.getDeltaTime());

That extra line may be causing your problem, nullifying your negative translation and doubling the positive one.

Upvotes: 2

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