在swift spritkit场景上淡出视频 [英] fading video over swift spritkit scene

问题描述

我正在将一个陈列室应用程序从as3 / starling移植到原生的快速iPad应用程序。

I am porting a showroom application from as3/starling to a native swift iPad app.

我有两个问题：

1. 如何通过我的spritekit内容（从alpha 0到1）淡化视频。

1. How can I fade a video over my spritekit content (from alpha 0 to 1).

如何使用单个UI元素控制iPad音量而不显示iOS屏幕上的音量通知图形。

How to control the iPad volume with an individual UI element without showing the iOS onscreen-volume notification graphic.

推荐答案

我的第一个答案回答了你的初步问题，这个答案是量身定制的到评论中发布的后续问题。我觉得这两个答案对社区都很有用，而不是只结合到一个我认为会让人困惑的答案。

My first answer answers your initial question, and this answer is tailored to the subsequent questions that were posted in the comments. I feel that both answers are useful to the community, instead of combining into just one which I think would be confusing.

这里我实现了一个音量滑块和一个擦洗滑块控制VideoNode的AVPlayer对象..您可以获得AVPlayer的全部功能，但具有SKVideoNode的便利性。此外，无需调整系统音量和随后的灰色音箱弹出即可控制播放视频的音量：

Here I implement a volume slider and a scrubbing slider that controls the VideoNode's AVPlayer object.. you get the full power of the AVPlayer but with the convenience of the SKVideoNode. Also, the volume for playing video is controlled without having to adjust the system volume and subsequent gray sound box pop-up:

import SpriteKit
import MediaPlayer


class GameScene: SKScene {

  let seekSlider = UISlider(frame: CGRect(x: 0, y: 0, width: 200, height: 15))
  let volSlider  = UISlider(frame: CGRect(x: 0, y: 0, width: 200, height: 15))

  // Because it takes time for us to load the video, we don't know it's duration,
  // hence we don't know what the `.maximumValue` should be for the seekSlider
  let defaultMax = Float(0.123456789)

  var player: AVPlayer!
  var videoNode: SKVideoNode!

  func seekSliderChangedValue(sender: UISlider) {
    // Wait for file to finish loading so we can get accurate end duration:
      if sender.maximumValue == defaultMax {
      if CMTimeGetSeconds(player.currentItem!.duration).isNaN { return }
      else { sender.maximumValue = Float(CMTimeGetSeconds(player.currentItem!.duration)) }
    }

    let value = CMTimeMake(Int64(seekSlider.value), 1)
    player.seek(to: value)
    player.play()
  }

  func volSliderChangedValue(sender: UISlider) {
    player.volume = sender.value
  }

  override func didMove(to view: SKView) {
    removeAllChildren()  // Delete this in your actual project.

    // Add some labels:
    let seekLabel = SKLabelNode(text: "Seek")
    seekLabel.setScale(3)
    seekLabel.verticalAlignmentMode = .center
    seekLabel.position = CGPoint(x: frame.minX + seekLabel.frame.width/2,
                                 y: frame.maxY - seekLabel.frame.height)
    let volLabel  = SKLabelNode(text: "Volume")
    volLabel.setScale(3)
    volLabel.verticalAlignmentMode = .center
    volLabel.position = CGPoint(x: frame.minX + volLabel.frame.width/2,
                                y: frame.minY + volLabel.frame.height + volSlider.frame.height)

    // Make player and node:
    let url = Bundle.main.url(forResource: "sample", withExtension: "mp4")!
    player = AVPlayer(url: url)
    videoNode = SKVideoNode(avPlayer: player!)

    //Configure seek slider:
    seekSlider.addTarget(self, action: #selector(seekSliderChangedValue), for: UIControlEvents.valueChanged)
    seekSlider.maximumValue = defaultMax
    let seekOrigin = convertPoint(toView: CGPoint(x: seekLabel.frame.minX, y: seekLabel.frame.minY))
    seekSlider.frame = CGRect(origin: seekOrigin, size: CGSize(width: 200, height: 15))

    //Configure vol slider:
    volSlider.addTarget(self, action: #selector(volSliderChangedValue), for: UIControlEvents.valueChanged)
    volSlider.value = 1
    let volOrigin = convertPoint(toView: CGPoint(x: volLabel.frame.minX, y: volLabel.frame.minY))
    volSlider.frame = CGRect(origin: volOrigin, size: CGSize(width: 200, height: 15))

    //Scene stuff:
    view.addSubview(seekSlider)
    view.addSubview(volSlider)
    addChild(seekLabel)
    addChild(volLabel)
    addChild(videoNode)

    // Start video and animation:
    videoNode.alpha = 0
    videoNode.play()
    videoNode.run(.fadeIn(withDuration: 5))
  }
}

这篇关于在swift spritkit场景上淡出视频的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！