Sprite kit - naming repeated objects - ios

Using apple spritekit, how can I uniquely identify nodes if, say 20 nodes, they have same art work and are to be placed randomly on the screen? Is there a faster way like in cocos2d there is a"tag" function to identify?

I'm not the most proficient with sprites, but is this something you're looking for?
Save:
NSArray * nodesArray; // some array of nodes.
for (int x = 0; x < nodesArray.count; x++) {
SKNode * node = nodesArray[x];
node.name = [NSString stringWithFormat:#"%i", x];
}
Retrieve:
int nodeToRetrieveTag = 2; // or whatever
SKNode* nodeToRetrieve = [self.scene childNodeWithName:[NSString stringWithFormat:#"%i", nodeToRetrieveTag]];

I'm usually using the property name:
SKNode *myNode = [[SKNode alloc]init];
myNode.name = #"uniqueName";
[self addChild:myNode];
In the SKScene, to recovery the node you can do:
[self childNodeWithName:#"uniqueName"]; // self is SKScene
If for some reason you don't want to use name, you can always subclass one SKNode and add your personal unique identifier:
MySpriteNode.h
#interface MySpriteNode : SKSpriteNode
#property (nonatomic, strong) NSString *personalIdentifier;
#end
and
MySpriteNode.m
#import "MySpriteNode.h"
#implementation MySpriteNode
#end
with this second option you can:
for (MySpriteNode *sprite in [self children]) personalIdentifier
{
if ([sprite.personalIdentifier isEqualToString:#"something"])
{
//do something
}
}
EDIT 1:
Try to follow these tutorials, I really think they are great. I learned a lot with them:
An iOS 7 Sprite Kit Game Tutorial
Sprite Kit Programming Guide
Sprite Kit Tutorial for Beginners

Are you looking for enumerateChildNodesWithName:usingBlock: method?

Related

Trying to access the Class from GameLayer

I have a custom class "LinkWithNumber" with three sprites
and on the GameLayer in update I am trying to test
CGRectContainsRect for collisions but I am having trouble trying to access the sprite in the class file (I don't have much experience so most likely I am messing up :P)
I have tried the following:
LinkWithNumber.h
#interface LinkWithNumber : SKSpriteNode <SKPhysicsContactDelegate>
{
SKSpriteNode *collide;
}
LinkWithNumber.m
#synthesize collide;
//add collision object to the class
collide = [[SKSpriteNode alloc]initWithColor:[SKColor blueColor]
...blah blah as normal
[self addChild:collide];
collide.name = #"collide";
GameLayer.h
#class LinkWithNumber;
#interface GameScene : SKScene <SKPhysicsContactDelegate>
{
LinkWithNumber* twoSpritesWithParticlesBridge;
}
#property (nonatomic, strong)LinkWithNumber* twoSpritesWithParticlesBridge;
GameLayer.m
#synthesize twoSpritesWithParticlesBridge;
-(void)addStaticLinkedSpriteWithParticles
{
twoSpritesWithParticlesBridge =
[[LinkWithNumber alloc]initWithlinkSpriteA:#"RoseMine06"
spriteB:#"RoseMine06"
andPlistAnimation:#"need to create animations"
distbetween:300
hasParticles:YES
ParticlesNamed:#"Fire"];
[self addChild:self->twoSpritesWithParticlesBridge];
twoSpritesWithParticlesBridge.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize: twoSpritesWithParticlesBridge.frame.size];
}
-(void)update:(CFTimeInterval)currentTime {
LinkWithNumber *currentSprite =
(LinkWithNumber*)[self childNodeWithName:#"collide"];
//NSLog(#"currentSprite Name #%#", currentSprite); //gets nil
if (CGRectContainsRect(myShip02.frame,currentSprite.frame)) {
NSLog(#"Hit barrier can pass");
}
}
Any help would be appreciated :)
How to locate your class object... The Solution, with thanks to 0x141E!
//name it on setup inside your customCLass
//eg yourObject.name = #"collide";
//Now in Gamelayer locate your object by recursive search
//it will look for any object named #"//collide"
//without the slashes it will only look on the game layer
//but since we need to dig a bit further we need them!
LinkWithNumber *currentSprite =
(LinkWithNumber*)[self childNodeWithName:#"//collide"];
NSLog(#"LinkWithNumber is %#",NSStringFromClass([currentSprite class]));
//do something with your object
if (currentSprite.position.y >0 ) {
NSLog(#"currentSprite Position %f",currentSprite.position.y);
}
extras
Sknode Class ref for other search functions
How to enumerate all nodes
I see two issues...
You are searching only the root node (in this case the scene) for the node named "collide", but that node is a child of LinkWithNumber node not the scene. To recursively search the entire node tree, use #"//collide"
You are casting the result of the search to a LinkWithNumber pointer, but collide is an SKSpriteNode not a LinkWithNumber.

How to update the score without generating countless nodes?

I have this game when a sprite touches the sides, you get a point. I figured out the code to increment the score each time the sprite touches the side. I get the correct output through the NSLog message.
But, When I try the same code by changing the code from NSLog to SKLabelNode, I get a more than a thousand nodes (which I think will affect the performance and slow the game).Also, when the score gets incremented, it overlaps the old score rather than just increasing the score. I have added the code in the update with frame.
Heres the code:
- (void)printScore {
NSString *text = [NSString stringWithFormat:#"%ld",(long)userScore];
SKLabelNode *score = [SKLabelNode labelNodeWithText:text];
score.fontName = #"chalkduster";
score.fontSize = 45;
score.fontColor = [SKColor whiteColor];
score.position = CGPointMake(CGRectGetMidX(self.frame) + 175 ,CGRectGetMidY(self.frame) + 350);
[self addChild:score];
}
-(void)update:(CFTimeInterval)currentTime {
[self printScore];
}
How do I fix this so that the score gets updated without so many sprites being added?
Sorry if this is a really dumb question, I am noob.
Add just a single property:
#property (nonatomic, strong) SKLabelNode *scoreLabel;
And create it just one time in viewDidLoad o an init method:
_scoreLabel = [SKLabelNode initWithFontNamed:#"chalkduster"];
_scoreLabel.fontSize = 45;
_scoreLabel.fontColor = [SKColor whiteColor];
_scoreLabel.position = CGPointMake(CGRectGetMidX(self.frame) + 175 ,CGRectGetMidY(self.frame) + 350);
[self addChild:_scoreLabel];
Then call the printScore method only when the sprite touches de sides, not on each frame like you are doing in the update method:
- (void)printScore
{
NSString *text = [NSString stringWithFormat:#"%ld",(long)userScore];
self.scoreLabel.text = text;
}
I hope this helps.
The reason you get so many nodes is that you are constantly adding new labels to the scene. Notice that in your printScore method you are create new SKLabelNode instances and then adding that to the scene.
In order to correct that, you will want to maintain a reference to a single SKLabelNode and then update the text of that.
Also, you may want to move the call to printScore to only be called when the actual scoring event happens, as opposed to update which is called for every frame. I'm of course assuming you do not have a scoring event happen every frame.
Your printScore method creates a new SKLabelNode every time it is called and you are calling it 60 times a second via your update method. You should set a BOOL to notify you of the need to call your printScoreMethod only when there is a need to do so (as in the score has changed).
create a global boolean and only add the label the first time:
BOOL firsttime = YES;
- (void)printScore {
NSString *text = [NSString stringWithFormat:#"%ld",(long)userScore];
SKLabelNode *score = [SKLabelNode labelNodeWithText:text];
if( firsttime )
{
score.fontName = #"chalkduster";
score.fontSize = 45;
score.fontColor = [SKColor whiteColor];
score.position = CGPointMake(CGRectGetMidX(self.frame) + 175, CGRectGetMidY(self.frame) + 350);
[self addChild:score];
firsttime = NO;
}
}
-(void)update:(CFTimeInterval)currentTime {
[self printScore];
}
There are a few ways to approach this. I prefer an approach which hides as much of the underlying implementation. Ideally, I would actually create a class which represents the score HUD. From a "rest of the app code" perspective, the other game code's contract with the HUD is through a score property which reflects the score.
Some will argue it is one label and it seems like a hassle. But if you change how it is implemented (for example, say it becomes a score with a fill bar or perhaps you have special effects which accompany a change in score), you will find it makes it super easy to deal with. Or what if you suddenly have a 2 player game and both players track score? You can easily add a new score by adding a new instance of your the score class.
Here is a simple example of what I mean.
ScoreHUD.h
#interface ScoreHUD : NSObject
#property (nonatomic, assign) NSInteger score;
- (instancetype)initWithScene:(SKScene *)scene x:(CGFloat)x y:(CGFloat)y;
#end
ScoreHUD.m
#interface ScoreHUD()
#property (nonatomic, strong) SKLabelNode *scoreLabel;
#end
#implementation ScoreHUD
- (instancetype)initWithScene:(SKScene *)scene x:(CGFloat)x y:(CGFloat)y
{
self = [super init];
if (self) {
_scoreLabel = [SKLabelNode initWithFontNamed:#"chalkduster"];
_scoreLabel.fontSize = 45;
_scoreLabel.fontColor = [SKColor whiteColor];
_scoreLabel.position = CGPointMake(x, y);
[scene addChild:_scoreLabel];
// Setting initial label value to the default value of the score
_scoreLabel.text = [#(_score) stringValue];
}
return self;
}
- (void)setScore:(NSInteger)score
{
if (_score != score) {
_score = score;
self.scoreLabel.text = [#(score) stringValue];
}
}
#end
Note that I haven't tested the code or checked to see if it would compile.
So to use this, you would create an instance of this in your scene like:
// Property in the scene
#property (nonatomic, strong) ScoreHUD *score;
// Initialize where you need to
self.score = [[ScoreHUD alloc] initWithScene:self x:CGRectGetMidX(self.frame) + 175 y:CGRectGetMidY(self.frame) + 350];
You could do this in your scene's initWithSize.
When the score changes, you simply do something like:
self.score.score += 1;
You can always wrap that in another method if it looks nasty to you.
There is a drawback to this method. Say your score get's updated a lot during a frame. This means your text would be set multiple times per frame. Depending on the type of game you have, this may or may not be a concern. There are ways to still have this basic setup and work around it. But for the vast majority of games, it will not be an issue.

SpriteKit: Making a character move in a world

i am trying to understand how you can make a huge world, and have a character move inside the world, and then it moves the visible part of the world with the moving character. Like the Mario game.
I read apples guide here: https://developer.apple.com/library/IOs/documentation/GraphicsAnimation/Conceptual/SpriteKit_PG/Actions/Actions.html#//apple_ref/doc/uid/TP40013043-CH4-SW32
on "centering the scene on a node" but i really couldn't understand it at all. I tried implementing it, but it did not work at all.
So, anyone able to help me here? A full example with some good comments on would be great.
Hope my question makes sense, thanks on advance everyone!
They try to talk with you "Your game world is a node and what you need to do only move the world node with your character".
Game "Adventure" - the example game for Sprite Kit will help you a lot to create a huge world like that.
https://developer.apple.com/LIBRARY/IOS/documentation/GraphicsAnimation/Conceptual/CodeExplainedAdventure/AdventureArchitecture/AdventureArchitecture.html
=> There are example Code of this game in documentary.
Besides, you can create "Tile map" to do the same.
I use a simple class AGMovingNode, inherited from SKNode as a background layer.
It's not perfect, but at least you can start from where.
Here is a code of the class:
AGMovingNode.h:
#import <SpriteKit/SpriteKit.h>
#interface AGMovingNode : SKNode
#property float pointsPerSecondSpeed;
- (instancetype)initWithPointsPerSecondSpeed:(float)pointsPerSecondSpeed;
- (void)update:(NSTimeInterval)currentTime paused:(BOOL)paused;
#end
AGMovingNode.m:
#import "AGMovingNode.h"
#implementation AGMovingNode
{
NSTimeInterval _lastUpdateTime;
NSTimeInterval _deltaTime;
}
- (instancetype)initWithPointsPerSecondSpeed:(float)pointsPerSecondSpeed {
if (self = [super init]) {
self.pointsPerSecondSpeed = pointsPerSecondSpeed;
}
return self;
}
- (void)update:(NSTimeInterval)currentTime paused:(BOOL)paused {
if (paused) {
_lastUpdateTime = 0;
return;
}
//To compute velocity we need delta time to multiply by points per second
if (_lastUpdateTime) {
_deltaTime = currentTime - _lastUpdateTime;
} else {
_deltaTime = 0;
}
_lastUpdateTime = currentTime;
CGPoint bgVelocity = CGPointMake(-self.pointsPerSecondSpeed, 0.0);
CGPoint amtToMove = CGPointMake(bgVelocity.x * _deltaTime, bgVelocity.y * _deltaTime);
self.position = CGPointMake(self.position.x+amtToMove.x, self.position.y+amtToMove.y);
}
#end
I found it in one of tutorials (can't remember which one right now) and slightly modified it.
I found it best if you use SKActions to move objects around.
What i do is have a method to reposition my character also with sprite animations (when he is standing and when he is walking):
- (void)moveUser:(CGPoint)position {
SKSpriteNode *user = (SKSpriteNode*)[self childNodeWithName:#"userSprite"];
// ... some logic to load correct atlas
NSArray *animationFrames = ...
SKAction *animation = [SKAction animateWithTextures:animationFrames timePerFrame:0.05f numberOfFrames:animationFrames.size];
SKAction *moveToPositionAction = [SKAction moveTo:position duration:0.4f];
[userNode runAction:[SKAction group:#[animation,moveToPositionAction]]];
}

Adding a CCSprite (NSObject) to a MutableArray crash

I have a "bomb" CCSprite in its own class(If people who doesn't use cocos2d reads this, CCSprite is a NSObject pretty much).
The CCSprite file looks like this:
Bomb.h:
#import <Foundation/Foundation.h>
#import "cocos2d.h"
#import <OpenAL/al.h>
#class HelloWorldLayer;
#interface Bomb : CCSprite {
#private
int length;
}
#property (readwrite) int length;
#end
Bomb.m:
#import "Bomb.h"
#implementation Bomb
#synthesize length = _length;
#end
I add it in my game layer (HelloWorldLayerlike a pro) with #class Bomb; in .h, and I import the Bomb.h in my HWLayer.m aswell and where I use it in my code, is here:
Bomb *bombe = [[Bomb alloc] init];
bombe.position = explosionPoint;
bombe.length = player.explosionLength; //player is another CCSprite class. This one is from the method. ....fromPlayer:(PlayerSprite *)player
//Logging here works, tested and the bombe.position is valid and .length is valid
[currentBombs addObject:bombe];
NSLog(#"%#",currentBombs); //Here doesn't, guessing crash is at ^
As said, it crashes on the addObject:line. I can't really see why, as I just replaced a not-classed CCSprite with a Bombclass.
The crash is just a (lldb) and the thing on the left outputs a few thousand of these:
Which says description, so I would assume its in my CCSprite subclass the error is. BUT the bombe.* logging worked fine!
Does anyone understand why it doesn't work?
Edit:
EDIT:
NSLog(#"%#",currentBombs); //Here doesn't, guessing crash is at ^
Your %# implies NSString. currentBombs is likely an int. Try
NSLog(#"%i",currentBombs); //Here doesn't, guessing crash is at ^
CCSprite requires a texture. You can (maybe?) have a CCSprite without one, but that's not what CCSprite is for.
You will want to use CCNode for this purpose:
CCNode* node = [CCNode new];
This is a full-fledged Cocos2d object that you can move, etc. You'd add your Bomb to it, and move the CCNode around, like this:
Bomb *myBomb = [Bomb new]; //or whatever
CCNode* bombNode = [CCNode new];
//add the bomb to the node
[bombNode addChild:myBomb];
//move the node
bombNode.position = CGPointMake(10, 20)
This allows you to remove the myBomb from your node, effectively having something that you can add whatever you want without needing to display anything, but when you want to, it can be done easily.
Good luck
try this method :
Bomb *bombe = [Bomb spriteWithFile:#"yourFile.png"];
bombe.position = explosionPoint;
bombe.length = player.explosionLength;
[currentBombs addObject:bombe];
NSLog(#"%#",currentBombs);

Implementing CCSprite class into my game

In my game, which is using cocos2d, there is going to be many different types of enemies, which all look different, and move all in different ways. Also, there is going to be a couple of different gamemodes, which both use the same enemies. As there will be different gamemodes, I decided to make each of my enemies have their own CCSprite class. In those there will be the way that the sprites move, the animation, etc. When one of these sprite is needed in my game, they will be spawned in to the scene. The only thing is, how do I do this? How do I call for one of the sprites to be create on the screen when they are using a class of their own?
If you want to tell me another way than having these sprites having their own classes, that is fine, but keep in mind that I will be having a couple of different gamemodes. If I do the code for the sprites in the CCLayer class of that gamemode, well I will have to write the code twice, which will take time.
Thanks.
You can just subclass CCSprite and override the default initializer initWithTexture:rect:
example taken from here
#implementation MySprite
-(id) initWithTexture:(CCTexture2D*)texture rect:(CGRect)rect
{
if( (self=[super initWithTexture:texture rect:rect]))
{
// initialize your ivars here
//ivar1 = xxx;
//ivar2 = yyy;
//ivar3 = zzz;
}
return self;
}
#end
// And to create an instance of MySprite you simply do:
MySprite *sprite = [MySprite spriteWithFile...];
// or any of the supported CCSprite methods.
you can have a super class say EnemySprite that looks like this
#interface EnemySprite : CCSprite
- (void)addToLayer:(CCLayer *)layer;
- (void)removeFromLayer:(CCLayer *)layer;
#end
than create a subclass for each type of enemy for example:
#inteface BigEnemySprite : EnemySprite
#end
#implementation BigEnemySprite
- (void)addToLayer:(CCLayer *)layer {
[layer addChild:self];
// animation code for your big enemy
}
- (void)removeFromLayer:(CCLayer *)layer {
[layer removeChild:self];
// animation code
}
#end
than you can use them like
EnemySprite *enemy = [BigEnemySprite spriteFromFile:file];
[enemy addToLayer:self];

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