art, life and software development

My adventures with the marvelous AndEngine library continue. I had just completed my live wallpaper BizarreMachine III. I could not be happier after all my travails setting up AndEngine for my Android project the thing was finally finished. I set about trying to export a release build when I hit  a huge snag. I got a Conversion to Dalvic failed with error 1. I started to Google frantically and for 4 days I got different solutions non of which worked.

The first was advice asking you to search for duplicated *.jars. I had none. Then there was advice to clean the project and restart Eclipse. I did that a number of times with no success.
Next was to download the latest version of Proguard and change the default Proguard settings in my project from this

call %java_exe% -jar "%PROGUARD_HOME%"\lib\proguard.jar %*
to
call %java_exe% -jar "%PROGUARD_HOME%"\lib\proguard.jar %1 %2 %3 %4 %5 %6 %7 %8 %9
There was also the advice to remove the android-support-v4.jar from the libs folder sans success.
In all this what was clear was the fact that it was a library issue.

The solution was this:

1. Go to the bin folders for AndEngine and AndEngineLiveWallpaperExtension.
2. Take the *.jars and save them in a folder in your project.
3. Unlink the AndEngine aand AndEngineLiveWallpaper libraries from your Project>Properties>Android Libraries tab.
4. Clean your project and Export. 

It should work, it worked for me

Caveat: I had to make these changes when the above method resulted in a java.lang.RuntimeException: Unable to instantiate service [name of package].[name of activity] on the exported apk.
Remove existing referencing libraries (Right click project > properties, remove the libraries under "Android" tab and those in buildpath except for your Android.X.X/
Go to your project, create a folder "libs"
Then place the jars into the folder (andengine.jar and andengineextension.jar etc)
Make them into buildpath by right click on the jars u just placed.

Backgrounds in AndEngine are created by adding Entities to the display stack. As far as I know (no doubt my views will change with new knowledge) there are 2 basic ways to do so. The first is using the SpriteBackground entity and the next using a Sprite. Any of these will create for you a simple flat background with your image of choice. Both are useful, however with the Sprite background I have found no way to control the scaling which seems to be automatic so except you are freezing your application in one orientation mode - Landscape or Portrait there will be squashing or stretching depending on your graphics. Sprites on the other hand by their nature do not change aspect ratio with an orientation change EXCEPT you have added some scaling instructions to the parent in which case the child (the sprite) will inherit its parents behaviour.
The caveat though is to only use the SpriteBackground if you are certain you are going to use a fixed oreintation otherwise all your Sprites will be distorted depending on the orientation of the user

Creating a SpriteBackground/ Sprite as a background
@Override
    public void onCreateResources(
            OnCreateResourcesCallback pOnCreateResourcesCallback)
            throws Exception {
        // TODO Auto-generated method stub
        BitmapTextureAtlasTextureRegionFactory.setAssetBasePath("gfx/");
        final BuildableBitmapTextureAtlas bitmapTextureAtlas = new BuildableBitmapTextureAtlas(
                mEngine.getTextureManager(), 1024, 1024,
                TextureOptions.BILINEAR);

        // Create the texture region
        mTextureRegion = BitmapTextureAtlasTextureRegionFactory
                .createFromAsset(bitmapTextureAtlas, this,
                        "myBackground.png");
        try {
            // Build/load the bitmap texture atlas
            bitmapTextureAtlas
                    .build(new BlackPawnTextureAtlasBuilder(
                            0, 0, 0));
            bitmapTextureAtlas.load();
        } catch (TextureAtlasBuilderException e) {
            e.printStackTrace();
        }

        pOnCreateResourcesCallback.onCreateResourcesFinished();
    }

    @Override
    public void onCreateScene(OnCreateSceneCallback pOnCreateSceneCallback)
            throws Exception {
        // TODO Auto-generated method stub
        mScene = new Scene();
       
        /*
         * Calculate the coordinates for the face, so its centered on the
         * camera.
         */
        final float centerX = (WIDTH - this.mTextureRegion.getWidth()) / 2;
        final float centerY = (HEIGHT - this.mTextureRegion.getHeight()) / 2;
       

        final Sprite spriteBG = new Sprite(centerX, centerY, this.mTextureRegion,
                this.getVertexBufferObjectManager());
//      Uncomment these 2 lines if you wish to use a SpriteBackground
//        SpriteBackground bg = new SpriteBackground(spriteBG);
//        mScene.setBackground(bg);


//      Comment this line if you have chosen to use a SpriteBackground
        mScene.attachChild(spriteBG);
       
       
        pOnCreateSceneCallback.onCreateSceneFinished(mScene);
    }

I recently began to work with a wonderful Android OpenGL ES framework called AndEngine. It comes in 2 versions, one for each of the OpenGL ES standards supported in Android, viz 1 and 2. From what I have been able to gather from a decent amount of Googling, most of the efforts are now being channeled to the OpenGL 2 version. This is the version I use and I will briefly discuss how to set it up.

To check if you have been successful do Properties>Android and your should see the Is Library radio button selected.