Chase Player With Camera In Andengine And Limit World's Bounds

Using AndEngine for Android, I would like to have my scene look like this: The red box is the world which must be limited to a given size, say 2000px*450px. The blue box is the Ca

Solution 1:

i think your question about the world boundaries is self answered, isn't it?

PhysicsWorld Boundaries

for further research you can download nicolas' AndEngine Examples App from the Play Store and look up the different examples here (GLES_2, didn't look for AnchorCenter yet): https://github.com/nicolasgramlich/AndEngineExamples/tree/GLES2/src/org/andengine/examples

Taken from the PhysicsExample, the code for the rectangles should look like this, if the bounds are set to the camera bounds. in your case, you can extend width like you want (3 times CAMERA_WIDTH?)

finalRectangleground=newRectangle(0, CAMERA_HEIGHT - 2, WORLD_WIDTH, 2, vertexBufferObjectManager);
    finalRectangleroof=newRectangle(0, 0, WORLD_WIDTH, 2, vertexBufferObjectManager);
    finalRectangleleft=newRectangle(0, 0, 2, CAMERA_HEIGHT, vertexBufferObjectManager);
    finalRectangleright=newRectangle(WORLD_WIDTH - 2, 0, 2, CAMERA_HEIGHT, vertexBufferObjectManager);

Camera following player for the Camera to follow your player, you can lookup the code of the BoundCameraExample https://github.com/nicolasgramlich/AndEngineExamples/blob/GLES2/src/org/andengine/examples/BoundCameraExample.java

the interesting part for you should be the addFace method at the bottom

privatevoidaddFace(finalfloat pX, finalfloat pY) {
    finalFixtureDefobjectFixtureDef= PhysicsFactory.createFixtureDef(1, 0.5f, 0.5f);
finalAnimatedSpriteface=newAnimatedSprite(pX, pY, this.mBoxFaceTextureRegion, this.getVertexBufferObjectManager()).animate(100);
finalBodybody= PhysicsFactory.createBoxBody(this.mPhysicsWorld, face, BodyType.DynamicBody, objectFixtureDef);
this.mScene.attachChild(face);
this.mPhysicsWorld.registerPhysicsConnector(newPhysicsConnector(face, body, true, true));

this.mBoundChaseCamera.setChaseEntity(face);
}

this method creates a physics body + sprite for "your player" (in this case, a boxed face) and sets the sprite as a chaseEntity for the camera to follow. Since the camera has bounds, that it can't exceed and your camera will have the height of your PhysicWorld boundaries, you can use this to let your camera follow the player in x, but not in y direction.

if you (i don't know why) don't want to use these boundaries, you can overwrite the onUpdate method of your Sprite and re-locate your camera only in x-direction, instead of xy coords

face.registerUpdateHandler(newIUpdateHandler() {
   @OverridepublicvoidonUpdate(finalfloat pSecondsElapsed) {
      float[] coord = face.getSceneCenterCoordinates();
      this.mBoundChaseCamera.setCenter(sceneCenterCoordinates[0], CAMERA_Y_POSITION);
   }
}

where the CAMERA_Y_POSITION is a static final field with the y-position.

I hope this answers your question(s). :-)

edit: oops, i forgot to mention, how to achieve the camera to be bound and i will edit the world width above:

this.mBoundChaseCamera.setBounds(0, 0,
            WORLD_WIDTH, CAMERA_HEIGHT);

all settings are like your image given (except the exact position of the face, that has to be given to the addFace(px, py))

Edit: Difference between scene boundaries in Andengine GLES2 vs GLES2-AnchorCenter

As far as i understood the question, i thought you would use GLES2, i thought of the (older) default GLES2 branch of AndEngine and posted the boundaries. As you found out yourself before and stated in the comments, you use another approach to set the rectangles - where you need to set the rectangles center as pX and pY. The reason for this is in fact, that with the AnchorCenter branch, you won't set the upper left position of an entity anymore and instead use it's center position.