学习文章
效果
Mask1.gif
Mask2.gif
源码
import UIKit
class ViewController: UIViewController {
var movedMask:CALayer?
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.blackColor()
mask()
// emitterMask()
}
func handlePan(recongnizer: UIPanGestureRecognizer) {
// 拖拽
let translation: CGPoint = recongnizer.translationInView(view)
recongnizer.view?.center = CGPoint(x: (recongnizer.view?.center.x)! + translation.x, y: (recongnizer.view?.center.y)! + translation.y)
recongnizer.setTranslation(CGPoint(x: 0, y: 0), inView: view)
// 关闭CoreAnimation实时隐式动画绘制(核心)
CATransaction.setDisableActions(true)
movedMask?.position = (recongnizer.view?.center)!
}
func mask() {
// 背景图片与mask图片
let backgroundImage: UIImage = UIImage(named: "background")!
let maskImage: UIImage = UIImage(named: "mask")!
// 背景图片显示
let backgroundIV: UIImageView = UIImageView(frame: view.bounds)
backgroundIV.image = backgroundImage.grayScale()
view.addSubview(backgroundIV)
// 遮罩图片显示
let backgroundChangedIV: UIImageView = UIImageView(frame: view.bounds)
backgroundChangedIV.image = backgroundImage
view.addSubview(backgroundChangedIV)
// 形成遮罩
movedMask = CALayer()
movedMask?.frame = CGRect(origin: CGPointZero, size: maskImage.size)
movedMask?.contents = maskImage.CGImage
movedMask?.position = view.center
backgroundChangedIV.layer.mask = movedMask
// 拖拽的view
let dragView: UIView = UIView(frame: CGRect(origin: CGPointZero, size: maskImage.size))
dragView.center = view.center
view.addSubview(dragView)
// 给dragView添加拖拽手势
let pan: UIPanGestureRecognizer = UIPanGestureRecognizer(target: self, action: "handlePan:")
dragView.addGestureRecognizer(pan)
}
func emitterMask() {
// 创建粒子layer
let snowEmitter: CAEmitterLayer = CAEmitterLayer()
// 粒子发射位置
snowEmitter.emitterPosition = CGPoint(x: 120, y: 0)
// 发射源的尺寸大小
snowEmitter.emitterSize = view.bounds.size
// 发射模式
snowEmitter.emitterMode = kCAEmitterLayerSurface
// 发射源的形状
snowEmitter.emitterShape = kCAEmitterLayerLine
// 创建雪花类型的粒子
let snowFlake: CAEmitterCell = CAEmitterCell()
// 粒子的名字
snowFlake.name = "snow"
// 粒子参数的速度乘数因子
snowFlake.birthRate = 15
snowFlake.lifetime = 60
// 粒子速度
snowFlake.velocity = 10
// 粒子的速度范围
snowFlake.velocityRange = 10
// 粒子y方向的加速度分量
snowFlake.yAcceleration = 20
// 周围发射角度
snowFlake.emissionRange = CGFloat(0.5 * M_PI)
// 子旋转角度范围
snowFlake.spinRange = CGFloat(0.25 * M_PI)
snowFlake.contents = UIImage(named: "snow")?.CGImage
// 设置雪花形状粒子的颜色
snowFlake.color = UIColor.whiteColor().CGColor
snowFlake.scale = 0.2
snowFlake.scaleRange = 0.2
snowEmitter.shadowOpacity = 1
snowEmitter.shadowRadius = 0
snowEmitter.shadowOffset = CGSizeZero
// 粒子边缘的颜色
snowEmitter.shadowColor = UIColor.whiteColor().CGColor
// 添加粒子
snowEmitter.emitterCells = [snowFlake]
// 将粒子layer添加进图层
view.layer.addSublayer(snowEmitter)
// 形成遮罩
let maskImage: UIImage = UIImage(named: "mask")!
movedMask = CALayer()
movedMask?.frame = CGRect(origin: CGPointZero, size: maskImage.size)
movedMask?.contents = maskImage.CGImage
movedMask?.position = view.center
snowEmitter.mask = movedMask
// 拖拽的view
let dragView: UIView = UIView(frame: CGRect(origin: CGPointZero, size: maskImage.size))
dragView.center = view.center
view.addSubview(dragView)
// 给dragView添加拖拽手势
let pan: UIPanGestureRecognizer = UIPanGestureRecognizer(target: self, action: "handlePan:")
dragView.addGestureRecognizer(pan)
}
}
