LibGDX-我的图像没有填满屏幕的宽度和高度

Question

I'm having a problem getting my image to fill the whole screen without stretching itself. Currently I have an orthographic Camera set up, but the issue is the origin (0,0) of the image displays in the middle of the screen. How can I make this work? Here is the code that I have.

public class GameScreen implements Screen {
   SlingshotSteve game; 

   public void Menu(SlingshotSteve game){
       this.game = game;
   }

   OrthographicCamera camera;

   SpriteBatch batch;
   TextureRegion backgroundTexture;
   Texture texture;

   GameScreen(final SlingshotSteve gam) {
        this.game = gam; 

    camera = new OrthographicCamera(800, 480);

    batch = new SpriteBatch();

    Texture texture = new Texture(Gdx.files.internal("background.jpg"));
    backgroundTexture = new TextureRegion(texture, 0, 0, 500, 500);

}

public void render(float delta) {   
      Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

      camera.update();
      batch.setProjectionMatrix(camera.combined);

      batch.begin();
      batch.draw(backgroundTexture, 0, 0, SlingshotSteve.WIDTH, SlingshotSteve.HEIGHT); 
      batch.end();

}

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

}

Answer 1

How is your Orthographic camera implemented? It sounds like you might be interested in the "pixel-perfect" transform, which allows screen co-ordinates to correlate directly to world co-ordinates. You can use the parameters below to implement this transformation.

final float lOrthoLeft   = 0;
final float lOrthoRight  = pScreenHeight;
final float lOrthoTop    = 0;
final float lOrthoBottom = pScreenWidth;
final float lOrthoNear   = Float.MIN_VALUE;
final float lOrthoFar    = Float.MAX_VALUE;

In this regard, it is possible that your values of lOrthoLeft , lOrthoRight , lOrthoTop and lOrthoBottom of your Orthographic projection are (-Width/2) , (+Width/2) , (-Height/2) , (+Height/2) (or some variation) in order to position the world's origin in the centre of the screen.

However, this does also have to do with how libgdx renders to the screen. OpenGL ES, the hardware-accelerated graphical API under the hood of libgdx uses a special co-ordinate system where the centre of the screen is used as the origin. You'll find these resources useful in understanding how to work within these domains.

libgdx co-ordinate system

Displaying Graphics with OpenGL ES