didBeginContact works absolutely incorrect swift - macos

Question

I have a very simple app on sprite kit for mac os. (BTW, this code for iOS is working correctly).
AppDelegate code:
import Cocoa
import SpriteKit
extension SKNode {
class func unarchiveFromFile(file : String) -> SKNode? {
if let path = NSBundle.mainBundle().pathForResource(file, ofType: "sks") {
var sceneData = NSData(contentsOfFile: path, options: .DataReadingMappedIfSafe, error: nil)!
var archiver = NSKeyedUnarchiver(forReadingWithData: sceneData)
archiver.setClass(self.classForKeyedUnarchiver(), forClassName: "SKScene")
let scene = archiver.decodeObjectForKey(NSKeyedArchiveRootObjectKey) as! GameScene
archiver.finishDecoding()
return scene
} else {
return nil
}
}
}
#NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {
#IBOutlet weak var window: NSWindow!
#IBOutlet weak var skView: SKView!
func applicationDidFinishLaunching(aNotification: NSNotification) {
/* Pick a size for the scene */
if let scene = GameScene.unarchiveFromFile("GameScene") as? GameScene {
/* Set the scale mode to scale to fit the window */
scene.scaleMode = .AspectFill
self.skView!.presentScene(scene)
/* Sprite Kit applies additional optimizations to improve rendering performance */
self.skView!.ignoresSiblingOrder = true
self.skView!.showsFPS = true
self.skView!.showsNodeCount = true
}
}
func applicationShouldTerminateAfterLastWindowClosed(sender: NSApplication) -> Bool {
return true
}
}
And the scene code:
import Foundation
import SpriteKit
struct Detection {
static var no : UInt32 = 0
static var all : UInt32 = UInt32.max
static var monster : UInt32 = 0b1
static var suric : UInt32 = 0b10
static var ninja : UInt32 = 0b100
}
func random() -> CGFloat {
return CGFloat(Float(arc4random()) / 0xFFFFFFFF)
}
func random(#min: CGFloat, max: CGFloat) -> CGFloat {
return random() * (max - min) + min
}
func + (left: CGPoint, right: CGPoint) -> CGPoint {
return CGPoint(x: left.x + right.x, y: left.y + right.y)
}
func - (left: CGPoint, right: CGPoint) -> CGPoint {
return CGPoint(x: left.x - right.x, y: left.y - right.y)
}
func * (point: CGPoint, scalar: CGFloat) -> CGPoint {
return CGPoint(x: point.x * scalar, y: point.y * scalar)
}
func / (point: CGPoint, scalar: CGFloat) -> CGPoint {
return CGPoint(x: point.x / scalar, y: point.y / scalar)
}
#if !(arch(x86_64) || arch(arm64))
func sqrt(a: CGFloat) -> CGFloat {
return CGFloat(sqrtf(Float(a)))
}
#endif
extension CGPoint {
func length() -> CGFloat {
return sqrt(x*x + y*y)
}
func normalized() -> CGPoint {
return self / length()
}
}
class GameScene: SKScene, SKPhysicsContactDelegate {
let player = SKSpriteNode(imageNamed: "player.png")
override func didMoveToView(view: SKView) {
backgroundColor = SKColor.whiteColor()
physicsWorld.gravity = CGVectorMake(0.0, 0.0)
physicsWorld.contactDelegate = self
player.position = CGPoint(x: self.size.width * 0.1, y: self.size.height / 2)
addChild(player)
runAction(SKAction.repeatActionForever(SKAction.sequence([SKAction.runBlock(createMonster), SKAction.waitForDuration(1)])))
}
override func mouseDown(theEvent: NSEvent) {
let location = theEvent.locationInNode(self)
let suric = SKSpriteNode(imageNamed: "projectile.png")
suric.position = player.position
suric.physicsBody = SKPhysicsBody(circleOfRadius: self.size.width / 2)
suric.physicsBody?.categoryBitMask = Detection.suric
suric.physicsBody?.collisionBitMask = Detection.no
suric.physicsBody?.contactTestBitMask = Detection.monster
suric.physicsBody?.usesPreciseCollisionDetection = true
suric.physicsBody?.dynamic = true
suric.physicsBody?.angularVelocity = -10.0
let offset = location - suric.position
if offset.x < 0 {
return
}
addChild(suric)
let direc = offset.normalized()
let shoot = direc * 1000
let dest = shoot + suric.position
let move = SKAction.moveTo(dest, duration: 2.0)
let stop = SKAction.removeFromParent()
suric.runAction(SKAction.sequence([move, stop]))
}
func suricHit(suric : SKSpriteNode?, monster : SKSpriteNode?) {
if suric != nil && monster != nil {
suric!.removeFromParent()
monster!.removeFromParent()
}
}
func didBeginContact(contact: SKPhysicsContact) {
var first : SKPhysicsBody
var second : SKPhysicsBody
if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
first = contact.bodyA
second = contact.bodyB
}
else {
first = contact.bodyB
second = contact.bodyA
}
if (first.categoryBitMask & Detection.monster != 0) && (second.categoryBitMask & Detection.suric != 0) {
suricHit(first.node as? SKSpriteNode, monster: second.node as? SKSpriteNode)
}
}
func createMonster() {
let monster = SKSpriteNode(imageNamed: "monster.png")
let y = random(min: monster.size.height / 2, size.height - monster.size.height)
monster.position = CGPoint(x: self.size.width + monster.size.width / 2, y: y)
monster.physicsBody = SKPhysicsBody(rectangleOfSize: monster.size, center: CGPoint(x: monster.position.x / 2, y: monster.position.y))
monster.physicsBody?.usesPreciseCollisionDetection = true
monster.physicsBody?.categoryBitMask = Detection.monster
monster.physicsBody?.contactTestBitMask = Detection.suric
monster.physicsBody?.collisionBitMask = Detection.no
monster.physicsBody?.dynamic = true
addChild(monster)
let duration = random(min: 2.0, 4.0)
let move = SKAction.moveTo(CGPoint(x: -monster.size.width / 2, y: y), duration: NSTimeInterval(duration))
let done = SKAction.removeFromParent()
monster.runAction(SKAction.sequence([move, done]))
}
}
And the contact function works really strange. It runs even without actual contact between suric and monster. I have no idea why this happens. Is it just my fault or just a Xcode bug?

Answer 1

Your physics body of projectile is too big. Nodes contacts through physics bodies not their actual sizes.
suric.physicsBody = SKPhysicsBody(circleOfRadius: self.size.width / 2)
change size of physics body to something smaller
self.size.width / 2
something like this
suric.physicsBody = SKPhysicsBody(circleOfRadius: suric.size);