android - SplashScene 未居中

Question

我正在试用 AndEngine，但无法弄清楚为什么我的启动画面没有位于设备的中央 - 请参见下图。我为设备 (800, 480) 设置了默认大小，并将启动画面放在 camera.getWidth()/2 处。看起来我的飞溅的一角正好击中了中心，但我希望飞溅的中心居中 - 有意义吗？

主要 Activity :

package com.example.caspe.getmeout;

import org.andengine.engine.Engine;
import org.andengine.engine.LimitedFPSEngine;
import org.andengine.engine.camera.Camera;
import org.andengine.engine.handler.timer.ITimerCallback;
import org.andengine.engine.handler.timer.TimerHandler;
import org.andengine.engine.options.ScreenOrientation;
import org.andengine.engine.options.WakeLockOptions;
import org.andengine.engine.options.resolutionpolicy.RatioResolutionPolicy;    
import org.andengine.engine.options.EngineOptions;
import org.andengine.entity.scene.Scene;
import java.io.IOException;


public class MainActivity extends BaseGameActivity {
    private ResourcesManager resourcesManager;
    private static final int CAMERA_WIDTH = 800;
    private static final int CAMERA_HEIGHT = 480;
    private Camera camera;

    public EngineOptions onCreateEngineOptions() {
        camera = new Camera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT);
        EngineOptions engineOptions = new EngineOptions(true, ScreenOrientation.LANDSCAPE_FIXED, new RatioResolutionPolicy(800, 480), this.camera);
        engineOptions.getAudioOptions().setNeedsMusic(true).setNeedsSound(true);
        engineOptions.setWakeLockOptions(WakeLockOptions.SCREEN_ON);
        return engineOptions;
    }

    @Override
    public Engine onCreateEngine(EngineOptions pEngineOptions) {
        return new LimitedFPSEngine(pEngineOptions, 60);
    }

    @Override
    public void onCreateResources(OnCreateResourcesCallback pOnCreateResourcesCallback) throws Exception {
        ResourcesManager.prepareManager(mEngine, this, camera, getVertexBufferObjectManager());
        resourcesManager = ResourcesManager.getInstance();
        pOnCreateResourcesCallback.onCreateResourcesFinished();
    }

    @Override
    public void onCreateScene(OnCreateSceneCallback pOnCreateSceneCallback) throws IOException {
        SceneManager.getInstance().createSplashScene(pOnCreateSceneCallback);
    }

    @Override
    public void onPopulateScene(Scene pScene, OnPopulateSceneCallback pOnPopulateSceneCallback) throws IOException {
        mEngine.registerUpdateHandler(new TimerHandler(2f, new ITimerCallback() {
            public void onTimePassed(final TimerHandler pTimerHandler) {
                mEngine.unregisterUpdateHandler(pTimerHandler);
                // load menu resources, create menu scene
                // set menu scene using scene manager
                // disposeSplashScene();
            }
        }));
        pOnPopulateSceneCallback.onPopulateSceneFinished();
    }

}

以及 Splash 的代码:

package com.example.caspe.getmeout;

import org.andengine.engine.camera.Camera;
import org.andengine.entity.sprite.Sprite;
import org.andengine.opengl.util.GLState;
import com.example.caspe.getmeout.BaseScene;
import com.example.caspe.getmeout.SceneManager.SceneType

public class SplashScene extends BaseScene {

    private Sprite splash;

    @Override
    public void createScene() {
        splash = new Sprite(0,0, resourcesManager.splash_region, vbom) {
            @Override
            protected void preDraw(GLState pGLState, Camera pCamera) {
                super.preDraw(pGLState, pCamera);
                pGLState.enableDither();
            }
        };

        splash.setScale(1.5f);
        splash.setPosition(camera.getWidth() / 2, camera.getHeight() / 2);
        attachChild(splash);
    }

    @Override
    public void onBackKeyPressed() {
    }

    @Override
    public SceneType getSceneType() {
        return SceneType.SCENE_SPLASH;
    }

    @Override
    public void disposeScene() {
        splash.detachSelf();
        splash.dispose();
        this.detachSelf();
        this.dispose();
    }

}

如果您需要比这更多的代码，请告诉我。我不是直接寻找一段有效的代码，而是更多地寻找我的错误所在，这样我就可以使用我的脑细胞并解决它 - 我只是在这里盯着自己瞎了眼。

Answer 1

splash.setPosition(camera.getWidth() / 2, camera.getHeight() / 2);

这还不够。您的启动画面实际上居中正确:左上角位于中心。

您还需要从位置中减去飞溅的半宽和半高。

// untested code
splash.setPosition(camera.getWidth() / 2 - splash.getWidth() / 2, camera.getHeight() / 2 - splash.getHeight() / 2);