Question

我正在尝试检测contactPoint与用户existing line之间的冲突currently drawing using finger。

这是我的代码：

let padding: CGFloat = 100
override func didMove(to view: SKView) {

    physicsWorld.contactDelegate = self

    let startPoint1 = CGPoint(x: self.frame.minX + padding , y: self.frame.minY + padding)
    let leftHorizontalPoint = CGPoint(x: self.frame.minX + padding, y: self.frame.maxY - padding)

    let line1 = SKShapeNode()
    let line_path:CGMutablePath = CGMutablePath()
    line_path.move(to: startPoint1)
    line_path.addLine(to: leftHorizontalPoint)
    line1.path = line_path
    line1.lineWidth = 3
    line1.strokeColor = UIColor.white
    addChild(line1)

    line1.physicsBody = SKPhysicsBody(edgeLoopFrom: line1.frame)
    line1.physicsBody?.isDynamic = true
    line1.physicsBody?.categoryBitMask = PhysicsCategory.solidLine
    line1.physicsBody?.collisionBitMask = PhysicsCategory.currentLine
    line1.physicsBody?.contactTestBitMask = PhysicsCategory.currentLine
}

然后在touchBegin上，touchMove＆amp; touchEnd我有以下代码：

var currentLineNode: SKShapeNode!
var startPoint: CGPoint = CGPoint.zero
func touchDown(atPoint pos : CGPoint) {
    startPoint = pos
}

func touchMoved(toPoint pos : CGPoint) {
    if currentLineNode != nil {
        currentLineNode.removeFromParent()
    }
    currentLineNode = SKShapeNode()
    currentLineNode.zPosition = 1
    let line_path:CGMutablePath = CGMutablePath()
    line_path.move(to: startPoint)
    line_path.addLine(to: pos)
    currentLineNode.path = line_path
    currentLineNode.lineWidth = 3
    currentLineNode.strokeColor = UIColor.red
    addChild(currentLineNode)

    currentLineNode.physicsBody = SKPhysicsBody(edgeLoopFrom: currentLineNode.frame)
    currentLineNode.physicsBody?.isDynamic = true
    currentLineNode.physicsBody?.categoryBitMask = PhysicsCategory.currentLine
    currentLineNode.physicsBody?.collisionBitMask = PhysicsCategory.solidLine
    currentLineNode.physicsBody?.contactTestBitMask = PhysicsCategory.solidLine
}

func touchUp(atPoint pos : CGPoint) {
    if currentLineNode != nil {
        currentLineNode.removeFromParent()
    }
    currentLineNode = SKShapeNode()
    let line_path:CGMutablePath = CGMutablePath()
    line_path.move(to: startPoint)
    line_path.addLine(to: pos)
    currentLineNode.path = line_path
    currentLineNode.lineWidth = 3
    currentLineNode.strokeColor = UIColor.red
    addChild(currentLineNode)

    currentLineNode.physicsBody = SKPhysicsBody(edgeLoopFrom: currentLineNode.frame)
    currentLineNode.physicsBody?.isDynamic = true
    currentLineNode.physicsBody?.categoryBitMask = PhysicsCategory.currentLine
    currentLineNode.physicsBody?.collisionBitMask = PhysicsCategory.solidLine
    currentLineNode.physicsBody?.contactTestBitMask = PhysicsCategory.solidLine
}

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

    for t in touches { self.touchDown(atPoint: t.location(in: self)) }
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    for t in touches { self.touchMoved(toPoint: t.location(in: self)) }
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    for t in touches { self.touchUp(atPoint: t.location(in: self)) }
}

override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
    for t in touches { self.touchUp(atPoint: t.location(in: self)) }
}

physicsWorld's contactDelegate如下:(代表甚至没有执行）

extension GameScene : SKPhysicsContactDelegate {
    func didBegin(_ contact: SKPhysicsContact) {
       // This never get detected :(
       print(contact.contactPoint)
       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
       }
    }
}

这是我的输出，即使从白色线传递它没有检测到碰撞。

可能有什么不对？对此有任何建议都会有所帮助。

Answer 1

您正在使用2个基于边缘的实体。无论您是否设置，基于边缘的实体始终为isDynamic = false。您需要至少1个基于体积的身体才能进行联系。

另外，除此之外，您不断删除并添加节点，这是一个糟糕的主意。

我建议只在touchesBegan上添加你的节点，然后只更新touchesMoved上的路径

Answer 2

您正在使用边循环创建物理实体。 Apple将边循环定义为......

边缘没有体积或质量，并且始终被视为isDynamic属性等于false。边缘可能只与基于体积的物理体碰撞。

将您的物理身体改为此作品

Add

还应该注意的是，在touchesEnded中改变你的物理身体是多余的，不会增加任何东西。我从touchesEnded中删除它并且工作正常

Spritkit：使用手指绘制线条时检测碰撞

2 个答案: