ios 实现简单的弹幕功能-百家乐凯发k8

let danmaku_speed: cgfloat = 150 // 弹幕每秒移动速度
 let danmaku_space_time: nstimeinterval = 1 // 弹幕之间的时间间隔
 let danmaku_max_row = 3 // 最多同时弹幕行数
 let danmakufont = uifont.systemfontofsize(18) // 弹幕字体大小
 var rowarray = array>(count: 3, repeatedvalue: array()) 
 var danmakuqueue = nsoperationqueue() // 队列
 class danmaku : nsobject{
  var msg: msg
  var view: uilabel?
  var size = cgsize(width: 0, height: 0)
  var row = 0
  var starttime: nsdate?
  var duration: nstimeinterval = 0
  var delay: nstimeinterval = 0
  
  init(_ msg: msg, _ row: int, _ delay: nstimeinterval = 0) {
   self.msg = msg
   self.row = row
   self.delay = delay
  }
 }
 
 func queuedanmaku(msg: msg) {
  danmakuqueue.addoperation(nsblockoperation(block: { [weak self] in
   if let weakself = self {
    repeat {
     //检测放第几行
     for var row = 0; row < weakself.danmaku_max_row;   row {
      let rowdanmaku = weakself.rowarray[row]
      if rowdanmaku.count == 0 {
       let danmaku = danmaku(msg, weakself.danmakufont, row)
       weakself.rowarray[row].append(danmaku)
       self?.performselectoronmainthread("senddanmaku:", withobject: danmaku, waituntildone: true)
       return
      } else {
       if let lastdanmaku = rowdanmaku.last {
        if let starttime = lastdanmaku.starttime {
         let now = nsdate()
         let seconds = now.timeintervalsincedate(starttime)
         let widthduration = double(lastdanmaku.size.width / weakself.danmaku_speed)
         
         var delay = seconds - weakself.danmaku_space_time - widthduration
         if delay >= 0 {
          delay = 0
         } else {
          if lastdanmaku.delay > lastdanmaku.duration {
           continue
          }
         }
    
         let danmaku = danmaku(msg, weakself.danmakufont, row, abs(delay)   lastdanmaku.delay)
         weakself.rowarray[row].append(danmaku)
         
         self?.performselectoronmainthread("senddanmaku:", withobject: danmaku, waituntildone: true)
         return
        }
       }
      }
     }
     
     sleep(1000)
    } while self != nil
   }
   
   }))
 }
 
 func senddanmaku(danmaku: danmaku) {
  let text = "\(danmaku.msg.user_name) : \(danmaku.msg.text)"
  let size = nsstring(string: text).sizewithattributes([nsfontattributename : danmakufont])
  let width = uiscreen.mainscreen().bounds.size.width
  let top = 54   danmaku.row * (int(size.height)   10)
  let label = uilabel(frame: cgrectmake(width, cgfloat(top), size.width, size.height))
  let duration = (width   size.width) / danmaku_speed
  danmaku.view = label
  danmaku.size = size
  danmaku.starttime = nsdate()
  danmaku.duration = nstimeinterval(duration)
  
  label.text = text
  label.font = danmakufont
  label.textcolor = uicolor.whitecolor()
  label.shadowcolor = uicolor.blackcolor()
  label.shadowoffset = cgsizemake(0, -1.0)
  
  self.view.addsubview(label)
  uiview.animatewithduration(double(duration), delay: danmaku.delay, options: uiviewanimationoptions.curvelinear, animations: { () -> void in
    label.left = -label.width
   }) { [weak self] (bool) -> void in
    if !(self?.rowarray[danmaku.row].isempty ?? true) {
     self?.rowarray[danmaku.row].removefirst()
    }
    label.removefromsuperview()
  }
 }