ZoomExample.java

package org.andengine.examples;

import org.andengine.engine.camera.SmoothCamera;
import org.andengine.engine.options.EngineOptions;
import org.andengine.engine.options.ScreenOrientation;
import org.andengine.engine.options.resolutionpolicy.RatioResolutionPolicy;
import org.andengine.entity.scene.IOnSceneTouchListener;
import org.andengine.entity.scene.Scene;
import org.andengine.entity.scene.background.Background;
import org.andengine.entity.sprite.Sprite;
import org.andengine.entity.util.FPSLogger;
import org.andengine.input.touch.TouchEvent;
import org.andengine.opengl.texture.TextureOptions;
import org.andengine.opengl.texture.atlas.bitmap.BitmapTextureAtlas;
import org.andengine.opengl.texture.atlas.bitmap.BitmapTextureAtlasTextureRegionFactory;
import org.andengine.opengl.texture.region.ITextureRegion;
import org.andengine.opengl.vbo.VertexBufferObjectManager;
import org.andengine.ui.activity.SimpleBaseGameActivity;

import android.widget.Toast;

/**
 * (c) 2010 Nicolas Gramlich
 * (c) 2011 Zynga
 *
 * @author Nicolas Gramlich
 * @since 11:54:51 - 03.04.2010
 */
public class ZoomExample extends SimpleBaseGameActivity {
	// ===========================================================
	// Constants
	// ===========================================================

	private static final int CAMERA_WIDTH = 720;
	private static final int CAMERA_HEIGHT = 480;

	// ===========================================================
	// Fields
	// ===========================================================

	private SmoothCamera mSmoothCamera;
	private BitmapTextureAtlas mBitmapTextureAtlas;
	private ITextureRegion mFaceTextureRegion;

	// ===========================================================
	// Constructors
	// ===========================================================

	// ===========================================================
	// Getter & Setter
	// ===========================================================

	// ===========================================================
	// Methods for/from SuperClass/Interfaces
	// ===========================================================

	@Override
	public EngineOptions onCreateEngineOptions() {
		Toast.makeText(this, "Touch and hold the scene and the camera will smoothly zoom in.\nRelease the scene it to zoom out again.", Toast.LENGTH_LONG).show();

		this.mSmoothCamera = new SmoothCamera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT, 10, 10, 1.0f);

		return new EngineOptions(true, ScreenOrientation.LANDSCAPE_FIXED, new RatioResolutionPolicy(CAMERA_WIDTH, CAMERA_HEIGHT), this.mSmoothCamera);
	}

	@Override
	public void onCreateResources() {
		BitmapTextureAtlasTextureRegionFactory.setAssetBasePath("gfx/");

		this.mBitmapTextureAtlas = new BitmapTextureAtlas(this.getTextureManager(), 32, 32, TextureOptions.BILINEAR);
		this.mFaceTextureRegion = BitmapTextureAtlasTextureRegionFactory.createFromAsset(this.mBitmapTextureAtlas, this, "face_box.png", 0, 0);
		this.mBitmapTextureAtlas.load();
	}

	@Override
	public Scene onCreateScene() {
		this.mEngine.registerUpdateHandler(new FPSLogger());

		final Scene scene = new Scene();
		scene.setBackground(new Background(0.09804f, 0.6274f, 0.8784f));

		/* Calculate the coordinates for the screen-center. */
		final float centerX = (CAMERA_WIDTH - this.mFaceTextureRegion.getWidth()) / 2;
		final float centerY = (CAMERA_HEIGHT - this.mFaceTextureRegion.getHeight()) / 2;

		/* Create some faces and add them to the scene. */
		final VertexBufferObjectManager vertexBufferObjectManager = this.getVertexBufferObjectManager();
		scene.attachChild(new Sprite(centerX - 25, centerY - 25, this.mFaceTextureRegion, vertexBufferObjectManager));
		scene.attachChild(new Sprite(centerX  + 25, centerY - 25, this.mFaceTextureRegion, vertexBufferObjectManager));
		scene.attachChild(new Sprite(centerX, centerY + 25, this.mFaceTextureRegion, vertexBufferObjectManager));

		scene.setOnSceneTouchListener(new IOnSceneTouchListener() {
			@Override
			public boolean onSceneTouchEvent(final Scene pScene, final TouchEvent pSceneTouchEvent) {
				switch(pSceneTouchEvent.getAction()) {
					case TouchEvent.ACTION_DOWN:
						ZoomExample.this.mSmoothCamera.setZoomFactor(5.0f);
						break;
					case TouchEvent.ACTION_UP:
						ZoomExample.this.mSmoothCamera.setZoomFactor(1.0f);
						break;
				}
				return true;
			}
		});

		return scene;
	}

	// ===========================================================
	// Methods
	// ===========================================================

	// ===========================================================
	// Inner and Anonymous Classes
	// ===========================================================
}