SKPhysicsJointFixed在SpriteKit和Swift中

时间:2015-08-19 15:02:19

标签: swift sprite-kit skphysicsbody skphysicsjoint skphysicscontact

我正在使用Sprite Kit和Swift制作一个游戏,我在屏幕底部有一个Sprite,从顶部掉下来的Sprite,我想抓住它并坚持底部的Sprite,所以我正在尝试使用SKPhysicsJointFixed,但是当物体碰撞而不是落在底部的物体碰撞并且附着它的物体时,似乎底部的Sprite适应掉落的精灵的物理特性然后从屏幕上掉下来用它。这是我在didBeginContact方法中的代码。 and skewer是底部Sprite的名称,它应始终位于底部而不会消失。

    if contact.bodyA.node!.name == "Skewer"
    {
        let boundX = skewer.physicsBody?.node?.position.x
        let fixedJoint = SKPhysicsJointFixed.jointWithBodyA(contact.bodyA.node!.physicsBody, bodyB: contact.bodyB.node!.physicsBody, anchor: CGPoint(x: boundX!, y: boundY))
        physicsWorld.addJoint(fixedJoint)

        //            contact.bodyB.node!.removeFromParent()
    }
    else
    {
        contact.bodyA!.node!.removeFromParent()
    }

和底部屏幕Sprite的物理在这里

func makeSkewer()

{
    skewer.name = "Skewer"

    skewer.position = CGPoint(x: size.width * 0.5, y: size.height * 0.244)

    skewer.physicsBody = SKPhysicsBody(rectangleOfSize: skewer.size)
    skewer.physicsBody?.affectedByGravity = false
    skewer.physicsBody?.categoryBitMask = kSkewerCategory
    skewer.physicsBody?.contactTestBitMask = kFoodCategory
    skewer.physicsBody?.collisionBitMask = kSceneEdgeCategory

    addChild(skewer)
}

和下降精灵的物理学在这里

func random() ->CGFloat
{
    return CGFloat(Float(arc4random()) / 0xFFFFFFFF)
}

func random(#min: CGFloat,max: CGFloat) -> CGFloat
{
    return random() * (max - min) + min
}

func addFood()
{
    let randomCatchIndex = Int(arc4random_uniform(UInt32(foods.count)))
    let food = SKSpriteNode(imageNamed: foods[randomCatchIndex])
    let actualX = random(min: food.size.width/2, max: size.width - food.size.width/2)
    let actualDuration = random(min: CGFloat(1.5), max: CGFloat(8.0))
    let actionMove = SKAction.moveTo(CGPoint(x: actualX, y: -food.size.height/2), duration: NSTimeInterval(actualDuration))
    let actionMoveDone = SKAction.removeFromParent()


    food.physicsBody = SKPhysicsBody(rectangleOfSize: food.size)
    food.position = CGPoint(x: actualX, y: size.height + food.size.height/2)

    food.physicsBody?.categoryBitMask = kFoodCategory
    food.physicsBody?.contactTestBitMask = kSkewerCategory
    food.physicsBody?.collisionBitMask = 0x0
    food.physicsBody?.dynamic = true
    food.runAction(SKAction.sequence([actionMove, actionMoveDone]))

    addChild(food)

}

1 个答案:

答案 0 :(得分:0)

将串肉设置为没有动态物理。你现在所拥有的是它不会受到重力的影响,一旦它锁定在食物上(向下移动并具有动量),扦子就随之移动。

在创建串时,运行以下行:

skewer.physicsBody?.dynamic = false

您现在也可以忽略affectedByGravity,因为这只会影响动态对象。