如何使字体文本可点击？

Question

我的游戏在屏幕上有 3 个BitmapFont（稍后会更多）。我希望能够触摸字体并在控制台中输出它的字符串，这样我就知道按下了哪个。我试图创建一个矩形，但我无法获得被触摸的BitmapFont 的字符串。

这是我创建BitmapFont的代码：

public class simple  implements ApplicationListener {
    private OrthographicCamera camera;
    private SpriteBatch batch;
    BitmapFont font;
    GlyphLayout layout;
    String a1 = "aa";
    String a2 = "bb";
    String a3 = "cc";
    int a = 0;
    @Override
    public void create() {
      camera = new OrthographicCamera();
      camera.setToOrtho(false, 800, 480);
      batch = new SpriteBatch();
      layout = new GlyphLayout();
      font = new BitmapFont(Gdx.files.internal("arial-15.fnt"));
   }
   @Override
   public void render() {
      Gdx.gl.glClearColor(0, 0, 0.2f, 1);
      Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);    
      camera.update();
      batch.setProjectionMatrix(camera.combined);
      batch.begin();
      for (int i =1; i< 4;i++){ 
          layout.setText(font, "a"+i);
          font.draw(batch, layout,200+(15*i),200 );
      }
      batch.end();  
  }

Answer 1

您希望拥有 String、BitmapFont、Layout 和定位的组合功能。最好的方法是为这个包含我们需要的所有内容的可点击字体创建一个class。我为你做了一些工作，因为我是个好人，实际上我还有很多其他事情要做：D。

public class ClickableFont {

//Declare the fields
private GlyphLayout layout;
private BitmapFont font;

private String text;

private int posX;
private int posY;

/**
 * Constructs clickable text from a font
 * @param text Text to display
 * @param posX X position of the text
 * @param posY Y position of the text
 */
public ClickableFont(String text, int posX, int posY) {
    this.text = text;
    this.posX = posX;
    this.posY = posY;

    font = new BitmapFont(Gdx.files.internal("arial-15.fnt"));
    layout = new GlyphLayout(font, text);

}

/**
 * @param batch Draws the text using the given SpriteBatch.
 * @param camera Requires a camera to calculate touches between screen and world.
 */
public void update(SpriteBatch batch, OrthographicCamera camera)
{
    checkClicked(camera);

    font.draw(batch, layout, posX, posY);
}

/**
 * Checks if this object is clicked and outputs to console
 * @param camera the camera
 */
private void checkClicked(OrthographicCamera camera)
{
    if (Gdx.input.justTouched())
    {
        //Get screen coordinates
        Vector3 touch = new Vector3(Gdx.input.getX(), Gdx.input.getY(), 0);
        //Transform screen touch to world coordinates using the camera you are drawing with
        camera.unproject(touch);

        //System.out.println(getRectangle());
        //System.out.println(touch);

        if (getRectangle().contains(touch.x, touch.y))
        {
            System.out.println(text + " has been clicked.");
        }
    }
}

/**
 * Creates a rectangle for the sprite to perform collision calculations.
 * Since it seems font.draw draws from top to bottom (coordinate system of LibGDX is not consistent)
 * We have to adept the rectangle position Y position
 * @return rectangle of font bounds
 */
private Rectangle getRectangle()
{
    return new Rectangle(posX, posY - (int)layout.height, (int)layout.width, (int)layout.height);
}
}

如您所见，它分步解决您的问题。解决问题就是你在编程中所做的一切。一个经验法则是永远不要让一个方法超过 10 行，不包括 cmets。可以例外，但任何大方法都可以分解成更易读的小方法。

现在如何使用这个 ClickableFont 类？

    public class simple  implements ApplicationListener {
    private OrthographicCamera camera;
    private SpriteBatch batch;
    //folowing are not nececary anymore since it's handled by the new class
    //BitmapFont font; 
    //GlyphLayout layout; 
    //String a1 = "aa";
    //String a2 = "bb";
    //String a3 = "cc";

    int a = 0;

    //Declare a list to hold your clickable fonts
    List<ClickableFont> clickableFonts = new ArrayList<ClickableFont>();

    @Override
    public void create() {
      camera = new OrthographicCamera();
      camera.setToOrtho(false, 800, 480);
      batch = new SpriteBatch();

    //Add clickable fonts to the list
      clickableFonts.add(new ClickableFont("aa", 200, 200));
      clickableFonts.add(new ClickableFont("bb", 200 + 150, 200));
      clickableFonts.add(new ClickableFont("cc", 200 + 150 * 2, 200));
   }

   @Override
   public void render() {
      Gdx.gl.glClearColor(0, 0, 0.2f, 1);
      Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);    
      camera.update();
      batch.setProjectionMatrix(camera.combined);
      batch.begin();
      /* replace your loop
      for (int i =1; i< 4;i++){ 
          layout.setText(font, "a"+i);
          font.draw(batch, layout,200+(15*i),200 );
      }*/
      for (ClickableFont font : clickableFonts)
      {
          font.update(batch, camera);
      }
      batch.end();  
  }