Question

我想使用libgdx作为基于屏幕宽高比缩放应用程序的解决方案。我找到了这个链接，我觉得它非常有用： http://blog.acamara.es/2012/02/05/keep-screen-aspect-ratio-with-different-resolutions-using-libgdx/

我对opengl非常生疏（多年来没有为它写过）我希望在这个链接上使用这个例子，这样就可以很容易地放置图像和形状。遗憾的是，起点在中间。我想在许多其他平台上使用它 - 左上角应为（0,0），右下角应为（targetWidth-1，targetHeight-1），从我记得的，我需要移动（翻译）和旋转相机，以实现它，但我不确定。

这是我修改的onCreate方法链接示例的代码：

    @Override
public void create()
  {
  camera=new OrthographicCamera(VIRTUAL_WIDTH,VIRTUAL_HEIGHT);
  // camera.translate(VIRTUAL_WIDTH/2,VIRTUAL_HEIGHT/2,0);
  // camera.rotate(90,0,0,1);
  camera.update();
  //
  font=new BitmapFont(Gdx.files.internal("data/fonts.fnt"),false);
  font.setColor(Color.RED);
  //
  screenQuad=new Mesh(true,4,4,new VertexAttribute(Usage.Position,3,"attr_position"),new VertexAttribute(Usage.ColorPacked,4,"attr_color"));
  Point bottomLeft=new Point(0,0);
  Point topRight=new Point(VIRTUAL_WIDTH,VIRTUAL_HEIGHT);
  screenQuad.setVertices(new float[] {//
      bottomLeft.x,bottomLeft.y,0f,Color.toFloatBits(255,0,0,255),//
          topRight.x,bottomLeft.y,0f,Color.toFloatBits(255,255,0,255),//
          bottomLeft.x,topRight.y,0f,Color.toFloatBits(0,255,0,255),//
          topRight.x,topRight.y,0f,Color.toFloatBits(0,0,255,255)});
  screenQuad.setIndices(new short[] {0,1,2,3});
  //
  bottomLeft=new Point(VIRTUAL_WIDTH/2-50,VIRTUAL_HEIGHT/2-50);
  topRight=new Point(VIRTUAL_WIDTH/2+50,VIRTUAL_HEIGHT/2+50);
  quad=new Mesh(true,4,4,new VertexAttribute(Usage.Position,3,"attr_position"),new VertexAttribute(Usage.ColorPacked,4,"attr_color"));
  quad.setVertices(new float[] {//
  bottomLeft.x,bottomLeft.y,0f,Color.toFloatBits(255,0,0,255),//
      topRight.x,bottomLeft.y,0f,Color.toFloatBits(255,255,0,255),//
      bottomLeft.x,topRight.y,0f,Color.toFloatBits(0,255,0,255),//
      topRight.x,topRight.y,0f,Color.toFloatBits(0,0,255,255)});
  quad.setIndices(new short[] {0,1,2,3});
  //
  texture=new Texture(Gdx.files.internal(IMAGE_FILE));
  spriteBatch=new SpriteBatch();
  spriteBatch.getProjectionMatrix().setToOrtho2D(0,0,VIRTUAL_WIDTH,VIRTUAL_HEIGHT);
  }

到目前为止，我已成功使用此代码以使用缩放坐标，并仍然保持纵横比（这很棒），但我没有成功将起点（0,0）移动到左上角。

请帮帮我。

编辑：好的，经过一些测试，我发现它不起作用的原因是我使用了spriteBatch。我认为它忽略了相机。此代码出现在渲染部分中。无论我对相机做什么，它仍然会显示相同的结果。

@Override
public void render()
  {
  if(Gdx.input.isKeyPressed(Keys.ESCAPE)||Gdx.input.justTouched())
    Gdx.app.exit();
  // update camera
  // camera.update();
  // camera.apply(Gdx.gl10);
  // set viewport
  Gdx.gl.glViewport((int)viewport.x,(int)viewport.y,(int)viewport.width,(int)viewport.height);
  // clear previous frame
  Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
  //
  final String msg="test";
  final TextBounds textBounds=font.getBounds(msg);
  spriteBatch.begin();
  screenQuad.render(GL10.GL_TRIANGLE_STRIP,0,4);
  quad.render(GL10.GL_TRIANGLE_STRIP,0,4);
  Gdx.graphics.getGL10().glEnable(GL10.GL_TEXTURE_2D);
  spriteBatch.draw(texture,0,0,texture.getWidth(),texture.getHeight(),0,0,texture.getWidth(),texture.getHeight(),false,false);
  spriteBatch.draw(texture,0,VIRTUAL_HEIGHT-texture.getHeight(),texture.getWidth(),texture.getHeight(),0,0,texture.getWidth(),texture.getHeight(),false,false);
  font.draw(spriteBatch,msg,VIRTUAL_WIDTH-textBounds.width,VIRTUAL_HEIGHT);
  spriteBatch.end();
  }

Answer 1

这些行：

camera.translate(VIRTUAL_WIDTH/2,VIRTUAL_HEIGHT/2,0);
camera.rotate(90,0,0,1);

应移动相机，使其达到您想要的效果。但是，我的代码还有一个：

camera.update()

调用translate后调用，看起来你错过了。 doc for Camera.update说：

update
public abstract void update()

Recalculates the projection and view matrix of this camera and the Frustum planes. Use this after you've manipulated any of the attributes of the camera.

android - 在libgdx上设置左上角的起点

1 个答案: