collision detection - How to detect contact regarding sprite texture -

i have bullet should fired @ block. bullet has 6 different random textures mimic different bullets. , block has 3 different textures chosen randomly there 3 different blocks. want specify in code if bullet texture red, , block texture red score should increase, if bullet red , block green game over. don't know how tell game in didbegincontact.

by have this: in gamescene & didmovetoview:

struct physicscategory { static let none      : uint32 = 0 static let       : uint32 = uint32.max static let cgyblock  : uint32 = 0b1        static let bullet    : uint32 = 0b10 }  bullet.physicsbody = skphysicsbody(texture: bullet.texture, size: self.bullet.size) bullet.physicsbody?.categorybitmask = physicscategory.bullet bullet.physicsbody?.contacttestbitmask = physicscategory.cgyblock bullet.physicsbody?.collisionbitmask = physicscategory.none bullet.physicsbody?.affectedbygravity = false bullet.physicsbody?.usesprecisecollisiondetection = true 

in didbegincontact:

func didbegincontact(contact: skphysicscontact) {  var firstbody: skphysicsbody var secondbody: skphysicsbody if contact.bodya.categorybitmask < contact.bodyb.categorybitmask { firstbody = contact.bodya secondbody = contact.bodyb } else { firstbody = contact.bodyb secondbody = contact.bodya }       if ((firstbody.categorybitmask & physicscategory.cgyblock != 0) &&         (secondbody.categorybitmask & physicscategory.bullet != 0))    //and here suppose need implement somehow  // && (bullet.texture = "redbullet") && (cgyblock.texture = "greenblock" || "blackblock")  {    gameover()             } 

but know not work. tried make switch statement inside curly brackets , didn't work either. how implement that?

update: how block made:

var cgyblock = skspritenode()  let cgyarray = ["cyanbox", "greenbox", "yellowbox"]  func addcgyline () {     cgyblock = skspritenode(imagenamed: "cyanbox")     var randomcgy = int(arc4random_uniform(3))     cgyblock.texture = sktexture(imagenamed: cgyarray[randomcgy])      cgyblock.physicsbody = skphysicsbody(texture: cgyblock.texture, size: cgyblock.size)     cgyblock.physicsbody?.dynamic = true     cgyblock.physicsbody?.categorybitmask = physicscategory.cgyblock     cgyblock.physicsbody?.contacttestbitmask = physicscategory.bullet     cgyblock.physicsbody?.collisionbitmask = physicscategory.none      cgyblock.position = cgpointmake(size.width + cgyblock.size.width/2, cgrectgetmidy(self.frame) + 60)      addchild(cgyblock)      let actionmove = skaction.moveto(cgpoint(x: -cgyblock.size.width/2, y: cgrectgetmidy(self.frame) + 60), duration: 3)      let actiondone = skaction.removefromparent()     cgyblock.runaction(skaction.sequence([actionmove, actiondone]))     skactiontimingmode.easeout } 

and runaction in didmovetoview.

bullets:

var cannon = skspritenode(imagenamed: "cannon") var bulletincannon = skspritenode() var bullet = skspritenode()  let bulletarray = ["redbullet","magentabullet", "bluebullet", "cyanbullet", "greenbullet", "yellowbullet"]  //didmovetoview:  var randombullet = int(arc4random_uniform(6))  bulletincannon = skspritenode(imagenamed: bulletarray[randombullet])  bulletincannon.position = cgpointmake(cgrectgetmidx(self.frame), cgrectgetmidy(self.frame))  addchild(bulletincannon)   //touchesended: var randombullet = int(arc4random_uniform(6))         bullet = skspritenode(texture: bulletincannon.texture)         bullet.position = cgpointmake(cgrectgetmidx(self.frame), cgrectgetmidy(self.frame))         bullet.name = bulletarray[randombullet]         bullet.physicsbody = skphysicsbody(texture: bullet.texture, size: self.bullet.size)         bullet.physicsbody?.dynamic = true         bullet.physicsbody?.categorybitmask = physicscategory.bullet         bullet.physicsbody?.contacttestbitmask = physicscategory.cgyblock         bullet.physicsbody?.collisionbitmask = physicscategory.none         bullet.physicsbody?.affectedbygravity = false         bullet.physicsbody?.usesprecisecollisiondetection = true          addchild(bullet)  bulletincannon.texture = sktexture(imagenamed: bulletarray[randombullet]) 

few ways go :

1. you can use node's userdata property.

   bullet.userdata = ["type" : "white"] 

   to access it:

   println(bullet.userdata?["type"]) 

2. you can create custom bullet class subclass of skspritenode , create property called "type", , in didbegincontact access property.

   class bullet: skspritenode {      var type:string = ""        init(type:string) {          self.type = type //later accessing bulletnode.type         //this simple example give basic idea  can do.         //in real app should implement kind of security check avoid wrong type         let texture = sktexture(imagenamed: type)          super.init(texture: texture, color: nil, size: texture.size())     }      required init(coder adecoder: nscoder) {         fatalerror("init(coder:) has not been implemented")     } } 

3. you can use bullet.name property well, , on creation set appropriately based on bullet/block colour. later in didbegincontact check bullet.name find out bullet type. same goes blocks.

   func spawnbulletwithtype(type:string) -> skspritenode{       //set texture based on type      //you can pass here white_bullet       let atlas = sktextureatlas(named: "myatlas")        //here, if passed white_bullet string, spritekit search texture called white_bullet.png      let bullet = skspritenode(texture:atlas.texturenamed(type))        bullet.name = type // name white_bullet, , search in didbegincontact       bullet.physicsbody = skphysicsbody(texture: bullet.texture, size: bullet.size)      bullet.physicsbody?.categorybitmask = physicscategory.bullet      bullet.physicsbody?.contacttestbitmask = physicscategory.cgyblock      bullet.physicsbody?.collisionbitmask = physicscategory.none      bullet.physicsbody?.affectedbygravity = false      bullet.physicsbody?.usesprecisecollisiondetection = true       return bullet } 

edit:

based on recent comments go this:

let bulletarray = ["redbullet","magentabullet", "bluebullet", "cyanbullet", "greenbullet", "yellowbullet"]  //didmovetoview:  var randombullet = int(arc4random_uniform(6))  let bullettype = bulletarray[randombullet]  bulletincannon.name = bullettype  bulletincannon = skspritenode(imagenamed: bullettype )  bulletincannon.position = cgpointmake(cgrectgetmidx(self.frame), cgrectgetmidy(self.frame))  addchild(bulletincannon)   //touchesended: var randombullet = int(arc4random_uniform(6))         bullet = skspritenode(texture: bulletincannon.texture)         bullet.name = bulletincannon.name         bullet.position = cgpointmake(cgrectgetmidx(self.frame), cgrectgetmidy(self.frame))          bullet.physicsbody = skphysicsbody(texture: bullet.texture, size: self.bullet.size)         bullet.physicsbody?.dynamic = true         bullet.physicsbody?.categorybitmask = physicscategory.bullet         bullet.physicsbody?.contacttestbitmask = physicscategory.cgyblock         bullet.physicsbody?.collisionbitmask = physicscategory.none         bullet.physicsbody?.affectedbygravity = false         bullet.physicsbody?.usesprecisecollisiondetection = true          addchild(bullet) let bullettype = bulletarray[randombullet]  bulletincannon.texture = sktexture(imagenamed: bullettype)  bulletincannon.name = bullettype