Question

在我试图制作的游戏中，用户可以使用虚拟操纵杆移动玩家，就像许多手机游戏一样。当手指放在屏幕上然后沿一个方向移动时（手指移动的距离不能产生差异），这会使玩家朝那个方向移动。

我在执行此操作时遇到了问题。当手指被拖动到屏幕的另一侧时，播放器仅朝向正确的方向。我认为问题在于屏幕上的touchDown和touchDragged发生了。如何使touchPosition独立于屏幕上的位置？

这是我的代码，prevTouchPoint是为了解决当手指不再移动但仍然在屏幕上时，播放器仍然朝着正确的方向移动。 position是玩家的位置。

    public void update(float delta) {
        if(moving) {
            Vector2 dif = touchPoint.sub(startPoint);
            touchPoint.set(prevTouchPoint);

            dif.nor();

            position.add(dif);
        }
    }

    @Override
    public boolean touchDown(int screenX, int screenY, int pointer, int button) {
        startPoint = viewport.unproject(new Vector2(screenX, screenY));
        moving = true;

        Gdx.app.log("Player", "TouchDown");

        return true;
    }

    @Override
    public boolean touchUp(int screenX, int screenY, int pointer, int button) {
        moving = false;

        startPoint.set(0, 0);
        touchPoint.set(0, 0);
        prevTouchPoint.set(0, 0);

        Gdx.app.log("Player", "TouchUp");

        return true;
    }

    @Override
    public boolean touchDragged(int screenX, int screenY, int pointer) {
        if(moving) {
            touchPoint = viewport.unproject(new Vector2(screenX, screenY));
            prevTouchPoint.set(touchPoint);

            Gdx.app.log("Player", "TouchDragged");

            return true;
        }
        else {
            return super.touchDragged(screenX, screenY, pointer);
        }
    }

谢谢

Answer 1

尝试这种方式：

public class GdxTest extends ApplicationAdapter implements InputProcessor{

    ExtendViewport viewport;
    SpriteBatch batch;
    Sprite sprite;
    Texture texture;
    Vector2 touchDown,drag,spritePos;

    @Override
    public void create() {

        viewport=new ExtendViewport(400,640);

        touchDown =new Vector2();
        drag =new Vector2();
        spritePos=new Vector2();

        batch=new SpriteBatch();
        sprite=new Sprite(texture=new Texture("badlogic.jpg"));
        sprite.setSize(100,100);

        Gdx.input.setInputProcessor(this);
    }

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

        batch.begin();
        sprite.draw(batch);
        batch.end();

        if(Gdx.input.isTouched()){

            Vector2 diff= drag.cpy().sub(touchDown);
            diff.nor();
            touchDown.set(drag);
            spritePos.add(diff.scl(3));
        }

        sprite.setPosition(spritePos.x-sprite.getWidth()/2,spritePos.y-sprite.getHeight()/2);
    }

    @Override
    public void resize(int width, int height) {
        viewport.update(width,height);
    }

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

    @Override
    public boolean keyDown(int keycode) {
        return false;
    }

    @Override
    public boolean keyUp(int keycode) {
        return false;
    }

    @Override
    public boolean keyTyped(char character) {
        return false;
    }

    @Override
    public boolean touchDown(int screenX, int screenY, int pointer, int button) {

        touchDown.set(screenX,screenY);
        viewport.unproject(touchDown);

        return false;
    }

    @Override
    public boolean touchUp(int screenX, int screenY, int pointer, int button) {

        touchDown.set(0,0);
        drag.set(0,0);

        return false;
    }

    @Override
    public boolean touchDragged(int screenX, int screenY, int pointer) {

        drag.set(screenX,screenY);
        viewport.unproject(drag);

        return false;
    }

    @Override
    public boolean mouseMoved(int screenX, int screenY) {
        return false;
    }

    @Override
    public boolean scrolled(int amount) {
        return false;
    }
}

减去2个向量的方向

1 个答案: