问题描述
我想在不重叠的随机位置创建一些精灵,这是我的代码:
I want to create some sprites at random positions without getting overlapped, here is my code :
var sprites = [SKSpriteNode]()
for index in 0...spriteArray {
let sprite = SKSpriteNode(imageNamed: named)
sprites.append(sprite)
checkInterception(sprite, sprite2: sprites)// positioning using a function
addChild(sprite)
}
我在这里检查重叠:
func checkInterception(sprite1: SKSpriteNode, sprite2: [SKSpriteNode]) {
let xPos = CGFloat( Float(arc4random()) / Float(UINT32_MAX)) * maxX
let yPos = CGFloat( Float(arc4random()) / Float(UINT32_MAX)) * maxY
sprite1.position = CGPoint(x: xPos, y: yPos )
for index in 0...sprite2.count-1 {
if sprite1.intersectsNode(sprite2[index]) {
let yPos = sprite1.position.y + sprite1.size.height
sprite1.position = CGPoint(x: xPos, y: yPos )
}
}
}
但有些精灵仍然会重叠.我知道 for 循环有些不对劲,但就是想不通.
But some sprites still get overlapped. I know there is something not right with the for loop, but just can't figure it out.
推荐答案
我相信有几种不同的方法可以解决这个问题,这将是最接近你已经写过的.
I am sure there are a few different ways to attack the problem and this would be the closest to what you already wrote.
let sprites = [SKSpriteNode]() //loaded with your sprites to spawn
let maxX = size.width //whatever your max is
let maxY = size.height //whatever your max is
var spritesAdded = [SKSpriteNode]()
for currentSprite in sprites{
addChild(currentSprite)
var intersects = true
while (intersects){
let xPos = CGFloat( Float(arc4random()) / Float(UINT32_MAX)) * maxX
let yPos = CGFloat( Float(arc4random()) / Float(UINT32_MAX)) * maxY
currentSprite.position = CGPoint(x: xPos, y: yPos )
intersects = false
for sprite in spritesAdded{
if (currentSprite.intersectsNode(sprite)){
intersects = true
break
}
}
}
spritesAdded.append(currentSprite)
}
要考虑的事情是,如果您还不知道在哪里可以安全地添加 sprite,那么您将面临性能风险.例如,添加最后一个精灵可能需要 1,000,000 次尝试,然后才会随机选择一个不与其他精灵相交的点.
Things to consider is if you don't already know where it is safe to add a sprite you run the risk of performance. For instance adding your last sprite may take 1,000,000 attempts before it randomly picks a point that doesn't intersect with others.
如果您不必一次将它们全部添加,我会在更新循环上解决问题并执行类似的操作...
If you don't have to have them all added at once I would attack the problem on the update loop and do something like this...
var sprites = [SKSpriteNode]() //loaded with your sprites to spawn
var maxX : CGFloat = 0.0 //whatever your max is
var maxY : CGFloat = 0.0 //whatever your max is
var spritesAdded = [SKSpriteNode]()
override func didMoveToView(view: SKView) {
maxX = size.width //whatever your max is
maxY = size.height //whatever your max is
}
func addSprite(){
if let currentSprite = sprites.first {
let xPos = CGFloat( Float(arc4random()) / Float(UINT32_MAX)) * maxX
let yPos = CGFloat( Float(arc4random()) / Float(UINT32_MAX)) * maxY
currentSprite.position = CGPoint(x: xPos, y: yPos )
for sprite in spritesAdded{
if (currentSprite.intersectsNode(sprite)){
return
}
}
addChild(currentSprite)
spritesAdded.append(currentSprite)
sprites.removeFirst()
}
}
override func update(currentTime: NSTimeInterval) {
addSprite()
}
有点粗略,但想法是每次更新都会尝试添加一个精灵.这样,如果您用完房间,它就不会锁定.希望这会有所帮助.
Kind of rough but the idea is every update it will try to add a sprite. This way if you run out of room it won't lock up. Hopefully that helps.
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