CODEWITHSUNDEEP
androidandengine
dnivra
dnivra

Reputation: 769

PhysicsHandler not working as expected - AndEngine

Guys am a complete newbie to AndEngine. I wanted to use the physics handler and went through the examples of andengine. So in my case i have a "ball" sprite which i can move by touching and a second "square" animated sprite which i expect to bounce of the walls. But it is just leaving the screen. Help me out...

    package com.Escapo;

    import org.anddev.andengine.engine.Engine;
    import org.anddev.andengine.engine.camera.Camera;
    import org.anddev.andengine.engine.handler.physics.PhysicsHandler;
    import org.anddev.andengine.engine.options.EngineOptions;
    import org.anddev.andengine.engine.options.EngineOptions.ScreenOrientation;
    import org.anddev.andengine.engine.options.resolutionpolicy.RatioResolutionPolicy;
    import org.anddev.andengine.entity.scene.Scene;
    import org.anddev.andengine.entity.scene.Scene.IOnSceneTouchListener;
    import org.anddev.andengine.entity.scene.background.ColorBackground;
    import org.anddev.andengine.entity.sprite.AnimatedSprite;
    import org.anddev.andengine.entity.sprite.Sprite;
    import org.anddev.andengine.entity.util.FPSLogger;
    import org.anddev.andengine.input.touch.TouchEvent;
    import org.anddev.andengine.opengl.texture.TextureOptions;
    import org.anddev.andengine.opengl.texture.atlas.bitmap.BitmapTextureAtlas;
    import    org.anddev.andengine.opengl.texture.atlas.bitmap.BitmapTextureAtlasTextureRegionFactory;
    import org.anddev.andengine.opengl.texture.region.TextureRegion;
    import org.anddev.andengine.opengl.texture.region.TiledTextureRegion;
    import org.anddev.andengine.ui.activity.BaseGameActivity;

    import android.view.Display;



    public class EscapoActivity extends BaseGameActivity {

private Camera mCamera;
private Scene mMainScene;

//main ball variables
private BitmapTextureAtlas mBitmapTextureAtlas;
private TextureRegion mPlayerTextureRegion;
private Sprite player;
//square
private BitmapTextureAtlas mBitmapTextureAtlas2;
private static final float DEMO_VELOCITY = 100.0f;
private TiledTextureRegion mFaceTextureRegion;
private static int cameraWidth;
private static int cameraHeight;
private Sprite square;
@Override
public void onLoadComplete() {


}

@Override
public Engine onLoadEngine() {

    final Display display = getWindowManager().getDefaultDisplay();

        cameraWidth = display.getWidth();

        cameraHeight = display.getHeight();



        mCamera = new Camera(0, 0, cameraWidth, cameraHeight);



        return new Engine(new EngineOptions(true, ScreenOrientation.LANDSCAPE,

            new RatioResolutionPolicy(cameraWidth, cameraHeight), mCamera));

}

@Override
public void onLoadResources() {



            mBitmapTextureAtlas = new BitmapTextureAtlas(512, 512,

                TextureOptions.BILINEAR_PREMULTIPLYALPHA);

            //square
            mBitmapTextureAtlas2 = new BitmapTextureAtlas(512, 512,

                    TextureOptions.BILINEAR_PREMULTIPLYALPHA);


            BitmapTextureAtlasTextureRegionFactory.setAssetBasePath("gfx/");



            mPlayerTextureRegion = BitmapTextureAtlasTextureRegionFactory

                .createFromAsset(this.mBitmapTextureAtlas, this, "ball.png",

                0, 0);

            //square
            this.mFaceTextureRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(this.mBitmapTextureAtlas2, this, "square.png", 0, 0, 1, 1);

            mEngine.getTextureManager().loadTextures(mBitmapTextureAtlas,mBitmapTextureAtlas2);




}

@Override
public Scene onLoadScene() {

     mEngine.registerUpdateHandler(new FPSLogger());



         mMainScene = new Scene();

         mMainScene

             .setBackground(new ColorBackground(0.09804f, 0.6274f, 0.8784f));


         final int PlayerX =(int) ((mCamera.getWidth() - mPlayerTextureRegion

                 .getWidth()) / 2);
         final int PlayerY = (int) ((mCamera.getHeight() - mPlayerTextureRegion

             .getHeight()) / 2);



         player = new Sprite(PlayerX, PlayerY, mPlayerTextureRegion) {

                 public boolean onAreaTouched(TouchEvent pSceneTouchEvent,float pTouchAreaLocalX, float pTouchAreaLocalY) {

                    this.setPosition(pSceneTouchEvent.getX()- this.getWidth() / 2, pSceneTouchEvent.getY()- this.getHeight() / 2);




                     return true;

                 }

             };
             mMainScene.registerTouchArea(player);

                mMainScene.setTouchAreaBindingEnabled(true);

         mMainScene.attachChild(player);
         //square
         final Ball ball = new Ball(2, 2, this.mFaceTextureRegion);
         final PhysicsHandler physicsHandler = new PhysicsHandler(ball);
         ball.registerUpdateHandler(physicsHandler);
         physicsHandler.setVelocity(DEMO_VELOCITY, DEMO_VELOCITY);

         mMainScene.getLastChild().attachChild(ball);

         return mMainScene;

}


private static class Ball extends AnimatedSprite {
    private final PhysicsHandler mPhysicsHandler;

    public Ball(final float pX, final float pY, final TiledTextureRegion pTextureRegion) {
            super(pX, pY, pTextureRegion);
            this.mPhysicsHandler = new PhysicsHandler(this);
            this.registerUpdateHandler(this.mPhysicsHandler);
    }

    @Override
    protected void onManagedUpdate(final float pSecondsElapsed) {
            if(this.mX < 0) {
                    this.mPhysicsHandler.setVelocityX(DEMO_VELOCITY);
            } else if(this.mX + this.getWidth() > cameraWidth) {
                    this.mPhysicsHandler.setVelocityX(-DEMO_VELOCITY);
            }

            if(this.mY < 0) {
                    this.mPhysicsHandler.setVelocityY(DEMO_VELOCITY);
            } else if(this.mY + this.getHeight() > cameraHeight) {
                    this.mPhysicsHandler.setVelocityY(-DEMO_VELOCITY);
            }

            super.onManagedUpdate(pSecondsElapsed);
    }
 }




 }

I have just tried to integrate the moving ball example http://code.google.com/p/andengineexamples/source/browse/src/org/anddev/andengine/examples/MovingBallExample.java Where am i going wrong?

Upvotes: 1

Views: 1267

Answers (1)

lemuel
lemuel

Reputation: 11

I'm not sure PhysicsHandler will solve your problems, because I think it's just supposed to help you move your Entity.

Try the Box2d extension to AndEngine.

From the AndEngine Examples, there's PhysicsJumpExample.java (called "Combining Physics and Touch" in the launcher) which basically makes an object jump if you touch it, so I guess it's near to what you want.

Here's some code from that file, to make walls:

//onCreateScene
    final VertexBufferObjectManager vertexBufferObjectManager = this.getVertexBufferObjectManager();
    final Rectangle ground = new Rectangle(0, CAMERA_HEIGHT - 2, CAMERA_WIDTH, 2, vertexBufferObjectManager);
    final Rectangle roof = new Rectangle(0, 0, CAMERA_WIDTH, 2, vertexBufferObjectManager);
    final Rectangle left = new Rectangle(0, 0, 2, CAMERA_HEIGHT, vertexBufferObjectManager);
    final Rectangle right = new Rectangle(CAMERA_WIDTH - 2, 0, 2, CAMERA_HEIGHT, vertexBufferObjectManager);

    final FixtureDef wallFixtureDef = PhysicsFactory.createFixtureDef(0, 0.5f, 0.5f);
    PhysicsFactory.createBoxBody(this.mPhysicsWorld, ground, BodyType.StaticBody, wallFixtureDef);
    PhysicsFactory.createBoxBody(this.mPhysicsWorld, roof, BodyType.StaticBody, wallFixtureDef);
    PhysicsFactory.createBoxBody(this.mPhysicsWorld, left, BodyType.StaticBody, wallFixtureDef);
    PhysicsFactory.createBoxBody(this.mPhysicsWorld, right, BodyType.StaticBody, wallFixtureDef);

    this.mScene.attachChild(ground);
    this.mScene.attachChild(roof);
    this.mScene.attachChild(left);
    this.mScene.attachChild(right);

To make the object jump, just set a set the velocity to negative gravity. Gravity pulls it back after it eventually reaches 0:

final Vector2 velocity = Vector2Pool.obtain(this.mGravityX * -50, this.mGravityY * -50);
    faceBody.setLinearVelocity(velocity);
    Vector2Pool.recycle(velocity);

Upvotes: 1

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