How do I initialize all scenes at the start in Sprite Kit? - ios

Question

Whenever I want to transition to a certain scene, it takes a couple of seconds before the SKTransition even starts. Is it possible to have all scenes initialized before the game starts?
NewScene *newScene = [NewScene sceneWithSize:self.size];
SKTransition *reveal = [SKTransition moveInWithDirection:SKTransitionDirectionUp duration:0.5];
reveal.pausesIncomingScene = NO;
[self.view presentScene:newScene transition:reveal];
I've tried this with didMoveToView as well:
#implementation NewScene
-(id)initWithSize:(CGSize)size {
if(self = [super initWithSize:size]) {
// Load a bunch of stuff like this:
SKSpriteNode *menuButton = [SKSpriteNode spriteNodeWithImageNamed:#"mainMenu"];
menuButton.position = CGPointMake(self.frame.size.width/2,self.frame.size.height/4);
menuButton.name = #"menuButton";
[self addChild:menuButton];
[menuButton setScale:0.8];
}
}
How can I make sure that my Sprite Kit game runs smoothly?
EDIT:
It turns out the problem was that I kept putting the main thread to sleep to fade out music. I've made all my audio methods run in the background and it works fine now.

Answer 1

A good approach is to load all resources asyncronously before SKScene's initialization. Apple uses this approach in Adventure game:
NewScene.h:
typedef void (^AGAssetLoadCompletionHandler)(void);
#interface GameScene : SKScene<SKPhysicsContactDelegate, UIGestureRecognizerDelegate>
+ (void)loadSceneAssetsWithCompletionHandler:(AGAssetLoadCompletionHandler)handler;
#end
NewScene.m:
#implementation NewScene
-(id)initWithSize:(CGSize)size {
if(self = [super initWithSize:size]) {
// Load a bunch of stuff like this:
SKSpriteNode *menuButton = [SKSpriteNode spriteNodeWithTexture:[self menuButtonTexture];
menuButton.position = CGPointMake(self.frame.size.width/2,self.frame.size.height/4);
menuButton.name = #"menuButton";
[self addChild:menuButton];
[menuButton setScale:0.8];
}
}
#pragma mark - Shared Assets
+ (void)loadSceneAssetsWithCompletionHandler:(AGAssetLoadCompletionHandler)handler {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
// Load the shared assets in the background.
[self loadSceneAssets];
if (!handler) {
return;
}
dispatch_async(dispatch_get_main_queue(), ^{
// Call the completion handler back on the main queue.
handler();
});
});
}
+ (void)loadSceneAssets {
sBackgroundTexture = [SKTexture textureWithImageNamed:#"background"];
sMenuButtonTexture = [SKTexture textureWithImageNamed:#"mainMenu"];
// etc.
}
static SKTexture *sBackgroundTexture = nil;
- (SKTexture *)backgroundTexture {
return sBackgroundTexture;
}
static SKTexture *sMenuButtonTexture = nil;
- (SKTexture *)menuButtonTexture {
return sMenuButtonTexture;
}
#end
Then just present NewScene from your UIViewController:
if (!self.skView.scene) {
CGSize viewSize = self.view.bounds.size;
// Here you can present some loading scene or splash screen
[NewScene loadSceneAssetsWithCompletionHandler:^{
NewScene *scene = [[NewScene alloc] initWithSize:viewSize];
[self.skView presentScene:scene transition:[SKTransition crossFadeWithDuration:1.f]];
}];
}