Question

我正在为Mac OS编写SpriteKit应用程序。我有两个物体（射弹和怪物）：

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

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]))

怪物代码：

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)
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]))

检测结构：

struct Detection {
    static var no : UInt32 = 0
    static var all : UInt32 = UInt32.max
    static var monster : UInt32 = 0b1
    static var suric : UInt32 = 0b10
}

然后我尝试检查这两个对象之间是否存在联系：

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)
    }
}

即使他们实际上没有联系，也能正常工作。例如，抛射物靠近窗户的顶部，怪物在底部，但这个功能有效。

修改

我将此代码添加到didBeginContact：

let nodeA = (first.node as! SKSpriteNode)
let nodeB = (second.node as! SKSpriteNode)  
println("\(nodeA.position)\t\(nodeA.size)")
println("\(nodeB.position)\t\(nodeB.size)")
println((contact.contactPoint))
println()

out的例子：

(510.201293945312, 285.025665283203)    (54.0, 80.0)
(532.54345703125, 378.878845214844) (20.0, 20.0)
(852.469543457031, 530.415222167969)

如您所见，节点的x位置是510和532，但是接触x点是852.我只是不知道如何以及为什么。有人有解决方案吗？

Answer 1

您在if语句中缺少一组额外的括号。

if ((first.categoryBitMask & Detection.monster != 0) && (second.categoryBitMask & Detection.suric != 0)) {
    suricHit(first.node as? SKSpriteNode, monster: second.node as? SKSpriteNode)
}

PS我按照本教程将项目放在GitHub上，检查出来！

didBeginContact无需联系swift即可工作

1 个答案: