How to Get the Original Filename of a Sprite/Texture in Swift

Getting the filename of an SKSpriteNode in Swift 3

It is stored in the description, so here is a nice little extension I made to rip it out.

extension SKTexture
{
    var name : String
    {
        return self.description.slice(start: "'",to: "'")!
    }
}

extension String {
    func slice(start: String, to: String) -> String? 
    {

        return (range(of: start)?.upperBound).flatMap 
        { 
          sInd in
            (range(of: to, range: sInd..<endIndex)?.lowerBound).map 
            {
                eInd in
                substring(with:sInd..<eInd)

            }
        }
    }
}
usage:

print(sprite.texture!.name)

SKTexture get image name

Hmm my strategy would be this:

On your ninja class have a property for your textures. Keep them around

@property (nonatomic, strong) NSArray * hitTextures;

Then store the hit textures (note this is a lazy loading getter method)

-(NSArray *)hitTextures{
    if (_hitTextures == nil){
        SKTexture *hit1 = [SKTexture textureWithImageNamed:@"Ninja_hit_1"];
        SKTexture *hit2 = [SKTexture textureWithImageNamed:@"Ninja_hit_2"];
        SKTexture *hit3 = [SKTexture textureWithImageNamed:@"Ninja_hit_3"];
        SKTexture *hit4 = [SKTexture textureWithImageNamed:@"Ninja_hit_4"];

        _hitTextures = @[hit1, hit2, hit3, hit4];
    }
    return _hitTextures;
}

Note that we don't need to make the SKTextureAtlas object explicitly:

When loading the texture data, Sprite Kit searches the app bundle for an image file with the specified filename. If a matching image file cannot be found, Sprite Kit searches for the texture in any texture atlases stored in the app bundle. If the specified image does not exist anywhere in the bundle, Sprite Kit creates a placeholder texture image.

Use this texture array to fill in your SKAction

    SKAction *hitAnimation = [SKAction animateWithTextures:self.hitTextures
                                              timePerFrame:0.1];

This allows you do change your -isHit method like so:

- (BOOL)isHit:(SKTexture *)texture
{
    NSUInteger index = [self.hitTextures indexOfObject:texture];

    if (index == 1 ||
        index == 2)
    {
        return YES;
    }

    return NO;
}

This way you don't rely on an implementation detail of the -description method that is subject to change.

Folder of images: create and fill SKShapeNodes, 1 of each

Too many requests , so I try to help you with some code:

Create a folder:

func createDir(folderName:String) {
        let fileManager = FileManager.default
        if let directory = fileManager.containerURL(forSecurityApplicationGroupIdentifier: "APP_GROUP_IDENTIFIER") {
            let newDirectory = directory.appendingPathComponent(folderName)
            try! fileManager.createDirectory(at: newDirectory, withIntermediateDirectories: false, attributes: nil)
        }
}

---

Now you have your folder so you can decide to save a file or to copy one file from documents to this new directory. I make an example for the last one.

Copy a file:

let fileManager = FileManager.default
do {
   try fileManager.copyItem(atPath: "hero.png", toPath: "subfolder/hero.swift")
}
catch let error as NSError {
   print("Something went wrong: \(error)")
}

---

Now you want to know how to extract all files from a directory.

Extract all files from a directory:

func extractAllFile(atPath path: String, withExtension fileExtension:String) -> [String] {
        let pathURL = NSURL(fileURLWithPath: path, isDirectory: true)
        var allFiles: [String] = []
        let fileManager = FileManager.default
        if let enumerator = fileManager.enumerator(atPath: path) {
            for file in enumerator {
                if #available(iOS 9.0, *) {
                    if let path = NSURL(fileURLWithPath: file as! String, relativeTo: pathURL as URL).path
                        , path.hasSuffix(".\(fileExtension)"){
                        allFiles.append(path)
                    }
                } else {
                    // Fallback on earlier versions
                }
            }
        }
        return allFiles
    }

Usage:

let folderPath = Bundle.main.path(forResource: "Images", ofType: nil)
let allPngFiles = extractAllFile(atPath: folderPath!, withExtension: "png") // returns file path of all the png files inside the folder

---

After that, you can create an array of SKShapeNode based from allPngFiles using fillTexture with a SKTexture created from each image and give to each node the name of the file used (so you know at the end also how many nodes you have created from array.count).

Setting a name to an SKSpriteNode?

There may be a better way to do this, but this is the first thing I thought of - make the playerTexture variable an array of tuples containing the texture and the name you want to give it:

 var playerTexture = [(SKTexture, String)]()

  playerTexture.append((SKTexture(imageNamed: “red”), "red"))
  playerTexture.append((SKTexture(imageNamed: “blue”), "blue"))
  playerTexture.append((SKTexture(imageNamed: “green”), "green"))

  let rand = Int(arc4random_uniform(UInt32(playerTexture.count)))
  let chosenColor = playerTexture[rand].0 as SKTexture
  let colorName = playerTexture[rand].1
  let playerSkin = chosenColor

  player = SKSpriteNode(texture: playerSkin)
  player.size = CGSize(width: 50, height: 50)
  player.position = location
  self.addChild(player)
  player.name = colorName

Animation atlas and dynamic physicsBody in Swift 3

Solution for isDynamic = false.

*Update to 2017 below

After days of test maded with my answer, Knight0fDragon answer's and some other ideas came from other SO answers (Confused and Whirlwind suggestions..) I've seen that there is a new problem : physicsBody can't propagate their properties to other bodies
adequately and correctly. In other words copy all properties from a body to another body it's not enough. That's because Apple restrict the access to some methods and properties of the physicsBody original class.
It may happen that when you launch a physicsBody.applyImpulse propagating adequately the velocity, the gravity isn't yet respected correctly. That's really orrible to see..and obviusly that's wrong.

So the main goal is: do not change the physicBody recreating it.In other words DON'T RECREATE IT!

I thought that, instead of creating sprite children, you could create a ghost sprites that do the work instead of the main sprite, and the main sprite takes advantage of the ghost changes but ONLY the main sprite have a physicsBody.

This seems to work!

import SpriteKit
class GameScene: SKScene {
    var knight: SKSpriteNode!
    private var ghostKnight:SKSpriteNode!
    var textures : [SKTexture] = [SKTexture]()
    var lastKnightTexture : SKTexture!
    override func didMove(to view: SKView) {
        self.physicsWorld.gravity = CGVector.zero
        let plist = "knight.plist"
        let genericAtlas = SKTextureAtlas(named:plist)
        let filename : String! = NSURL(fileURLWithPath: plist).deletingPathExtension!.lastPathComponent
        for i in 0 ..< genericAtlas.textureNames.count
        {
            let textureName = (String(format:"%@%02d",filename,i))
            textures.append(genericAtlas.textureNamed(textureName))
        }
        if textures.count>0 {
            // Prepare the ghost
            ghostKnight = SKSpriteNode(texture:textures.first)
            addChild(ghostKnight)
            ghostKnight.alpha = 0.2
            ghostKnight.position = CGPoint(x:self.frame.midX,y:100)
            lastKnightTexture = ghostKnight.texture
            // Prepare my sprite
            knight =  SKSpriteNode(texture:textures.first,size:CGSize(width:1,height:1))
            knight.zPosition = 2
            addChild(knight)
            knight.position = CGPoint(x:self.frame.midX,y:self.frame.midY)
        }
        let ghostAnimation = SKAction.repeatForever(SKAction.animate(with: textures, timePerFrame: 0.15, resize: true, restore: false))
        ghostKnight.run(ghostAnimation,withKey:"ghostAnimation")
        let animation = SKAction.repeatForever(SKAction.animate(with: textures, timePerFrame: 0.15, resize: false, restore: false))
        knight.run(animation,withKey:"knight")

    }
    override func didEvaluateActions() {
        if ghostKnight.action(forKey: "ghostAnimation") != nil {
            if ghostKnight.texture != lastKnightTexture {
                setPhysics()
                lastKnightTexture = ghostKnight.texture
            }
        }
    }
    func setPhysics() {
        if let _ = knight.physicsBody{
            knight.xScale = ghostKnight.frame.size.width
            knight.yScale = ghostKnight.frame.size.height
        } else {
            knight.physicsBody = SKPhysicsBody.init(rectangleOf: knight.frame.size)
            knight.physicsBody?.isDynamic = true
            knight.physicsBody?.allowsRotation = false
            knight.physicsBody?.affectedByGravity = true
        }
    }
}

Output:

Obviusly you can hide with alpha set to 0.0 and re-positioning the ghost as you wish to make it disappear.

---

Update 2017:

After hours of testing I've try to improve the code, finally I managed to remove the ghost sprite but, to work well, one condition is very important: you should not use SKAction.animate with resize in true. This because this method resize the sprites and don't respect the scale (I really don't understand why, hope to some future Apple improvements..). This is the best I've obtain for now:

• NO CHILDS
• NO OTHER GHOST SPRITES
• NO EXTENSION
• NO ANIMATE METHOD RECREATED

Code:

import SpriteKit
class GameScene: SKScene {
    var knight: SKSpriteNode!
    var textures : [SKTexture] = [SKTexture]()
    var lastKnightSize: CGSize!
    override func didMove(to view: SKView) {
        self.physicsWorld.gravity = CGVector.zero
        let plist = "knight.plist"
        let genericAtlas = SKTextureAtlas(named:plist)
        let filename : String! = NSURL(fileURLWithPath: plist).deletingPathExtension!.lastPathComponent
        for i in 0 ..< genericAtlas.textureNames.count
        {
            let textureName = (String(format:"%@%02d",filename,i))
            textures.append(genericAtlas.textureNamed(textureName))
        }
        if textures.count>0 {
            // Prepare my sprite
            knight =  SKSpriteNode(texture:textures.first,size:CGSize(width:1,height:1))
            knight.zPosition = 2
            addChild(knight)
            knight.position = CGPoint(x:self.frame.midX,y:self.frame.midY)
            lastKnightSize = knight.texture?.size()
            setPhysics()
        }
        let animation = SKAction.repeatForever(SKAction.animate(with: textures, timePerFrame: 0.15, resize: false, restore: false))
        knight.run(animation,withKey:"knight")
    }
    override func didEvaluateActions() {
        lastKnightSize = knight.texture?.size()
        knight.xScale = lastKnightSize.width
        knight.yScale = lastKnightSize.height
    }
    func setPhysics() {
        knight.physicsBody = SKPhysicsBody.init(rectangleOf: knight.frame.size)
        knight.physicsBody?.isDynamic = true
        knight.physicsBody?.allowsRotation = false
        knight.physicsBody?.affectedByGravity = true
    }
}

Important detail:

About isDynamic = true that's not possible simply because , during the frequently changes of size, Apple reset also frequently the knight physicsBody but don't apply the inherit of the latest physicsBody properties to the new resetted physicsBody, this is a real shame, you can test it in update printing the knight.physicsBody?.velocity (is always zero but should change due to gravity...). This is probably the reason why Apple recommended to don't scale sprites during physics. To my point of view is a Sprite-kit limitation.

Horizontally mirror a SKSpriteNode texture

You can use this code to flip among x-axis:

spriteNode.xScale = spriteNode.xScale * -1;

but be careful you can lose some of physicsbody's property, I highly suggest u to use xScale in this way:

spriteNodeBody = [SKNode node];
spriteNodeBody.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:spriteNode.size];
spriteNodeBody.physicsBody.categoryBitMask = CNPhysicsCategoryPlayer;
spriteNodeBody.physicsBody.collisionBitMask = CNPhysicsCategoryBall;

[spriteNodeBody addChild:spriteNode];
[self addChild:spriteNodeBody];

And now you can safely use:

    spriteNode.xScale = spriteNode.xScale * -1;

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