January 2020
Intermediate to advanced
356 pages
6h 4m
Chinese
Content preview from Swift游戏开发经典实例
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
230
｜
第
7
章
为
2.0
表示物体运动速度将加快至原来的
2
倍（不过，调快物理模拟时钟速度会增
加物理模拟的不稳定性）。
同理，我们也可以用这个属性创建一种“慢镜头”效果：将
speed
属性设置为大于
0
但小于
1
的数，将使时钟变慢，这在凸显某种动人心扉的画面或者爆炸场景时比
较有用。
7.11
碰撞检测
问题
我们想判断碰撞什么时候发生。
解决方案
首先，让你的
SKScene
子类实现
SKPhysicsContactDelegate
协议。
然后，实现
didBeginContact
和
didEndContact
方法：
func didBegin(_ contact: SKPhysicsContact) {
print("Contact started between \(contact.bodyA) and \(contact.bodyB)")
}
func didEnd(_ contact: SKPhysicsContact) {
print("Contact ended between \(contact.bodyA) and \(contact.bodyB)")
}
在创建完我们的场景内容之后，将物理世界的
contactDelegate
属性为设置为这个
场景：
self.physicsWorld.contactDelegate = self
随后，将所有需要接收碰撞检测通知的物体的
contactTestBitMask
设置为非零的
值，如
0x01
。例如我们先将这个值存到一个常量：
let myObjectBitMask ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.