SpriteKit - Edge doesn't behave as expected

Question

In order to define an rectangular edge, this is the code I wrote:

-(void)didMoveToView:(SKView *)view {
/* Setup your scene here */

SKNode *edge = [SKNode node];

edge.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];

[self addChild:edge];

}

I want this edge to wrap the whole screen, i.e bottom, top, left and right borders.

I wish that the objects that I add to my scene bounce on all borders. But, those objects only bounce on bottom and top part of the edge.

P.S: The same code, worked about a year ago when SpriteKit GameScene.mclass had -(id)initWithSize:(CGSize)size instead of -(void)didMoveToView:(SKView *)view.

Answer 1

Currently SpriteKit by default loads a scene from .sks file and by default, the scene size is set to 1024x768. That is probably why you are getting unexpected results (self.frame has different size in compare to a view).

There are few things you should keep in mind these days:

• When scene is loaded from .sks file, initWithSize: is never called. initWithCoder: is called instead. If you want to use initWithSize: you should create a scene in "old" way - using sceneWithSize:

• In initWithSize: the view is always nil, so all the code which requires a view, should be moved to didMoveToView.

• In viewDidLoad a final size of a view may not be known yet. A proper implementation of viewWillLayoutSubviews can be used to get around this. Read more here.

What I would suggest you, is to create a scene inside viewWillLayoutSubviews using sceneWithSize: method and initialize it with view.bounds.size. After that, you can create borders like this:

self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];

Hint: It can be useful to enable visual physics representation. You can do this from view controller:

skView.showsPhysics = YES;

If all this doesn't help, check if your view has correct size. View can be wrongly sized if wrong launch images are supplied.

Hope this helps and make sense.