IOS粒子系统的实现

IOS粒子系统的实现

 IOS的CoreGraphic可以实现简单的粒子系统的效果
我们来简单介绍一下，实现粒子系统其实非常简单，比较复杂的是其参数的设置
实现粒子系统主要用到两个类
CAEmitterLayer和 CAEmitterCell  
先介绍一下 CAEmitterLayer (发射层)
其主要的属性有

@property(copy) NSArray *emitterCells; //粒子单元数组，有多少个粒子单元
@property float birthRate; 出生率因子，每秒产生的粒子数量，默认是1
@property float lifetime; 生命周期，单位是秒，默认是1
@property CGPoint emitterPosition; 粒子位置默认是CGPointZero
@property CGFloat emitterZPosition;  Z轴位置默认是0
@property CGSize emitterSize;  发射尺寸
@property CGFloat emitterDepth; 发射深度依赖属性emitterShape，可以被忽略
 @property(copy) NSString *emitterShape;发射形状
kCAEmitterLayerPoint 点 默认值
kCAEmitterLayerLine 线
kCAEmitterLayerRectangle 三角
kCAEmitterLayerCuboid 立方
kCAEmitterLayerCircle 圆
kCAEmitterLayerSphere 球
@property(copy) NSString *emitterMode; 发射模式
kCAEmitterLayerPoints 点群
kCAEmitterLayerOutline 轮廓
kCAEmitterLayerSurface 地面
kCAEmitterLayerVolume 团 默认值
@property(copy) NSString *renderMode;//渲染模式
kCAEmitterLayerUnordered 无序的  默认值
kCAEmitterLayerOldestFirst 从头开始
kCAEmitterLayerOldestLast 从后面开始
kCAEmitterLayerBackToFront 按照z轴
kCAEmitterLayerAdditive 加法的
@property BOOL preservesDepth; 保留深度，默认为No，如果为true会导致某些属性不确定 
@property float velocity; 速度 默认为1
@property float scale; 比例，默认为1 
@property float spin; 旋转角度
@property unsigned int seed; 粒子数量 默认是0

CAEmitterCell的 的类的主要属性有 
+ (id)emitterCell; 构造方法
+ (id)defaultValueForKey:(NSString *)key;根据keyPath读取效果
- (BOOL)shouldArchiveValueForKey:(NSString *)key; 保存效果
@property(copy) NSString *name; 根据keyPath构造
@property(getter=isEnabled) BOOL enabled; 能否被渲染
@property float birthRate;
@property float lifetime, lifetimeRange;   lifetimeRange生命周期范围，默认是0
@property CGFloat emissionLatitude, emissionLongitude; 粒子经纬度 默认是0  z轴和x轴的位置
@property CGFloat emissionRange; 发射角度，默认是0
@property CGFloat velocity, velocityRange;  速度，速度范围
@property CGFloat xAcceleration, yAcceleration, zAcceleration; 三方向加速度
@property CGFloat scale, scaleRange, scaleSpeed; 缩放，缩放范围，缩放速度
@property CGFloat spin, spinRange; 旋转角度 旋转范围
@property CGColorRef color; 粒子颜色
@property float redRange, greenRange, blueRange, alphaRange; 颜色范围和透明度范围
@property float redSpeed, greenSpeed, blueSpeed, alphaSpeed; 速度
@property(retain) id contents; 内容 类型是CGImageRef 默认是nil
@property CGRect contentsRect; 内容范围 默认是[0,0,1,1]
@property(copy) NSString *minificationFilter, *magnificationFilter; 过滤
@property float minificationFilterBias;
@property(copy) NSArray *emitterCells; 发射的子粒子
@property(copy) NSDictionary *style; 继承layer的属性

   

        

     

本人写的Demo
粒子层类 

 

#ifndef IPhone5

    #define IPhone5 ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 1136), [[UIScreen mainScreen] currentMode].size) : NO)

#endif

#import 

typedef enum
{
    PaticleFromePositionModeNone,
    PaticleFromePositionModeTop,
    PaticleFromePositionModeCenter,
    PaticleFromePositionModeBottom
}
PaticleFromePositionMode;

@interface PaticleLayer : CAEmitterLayer
//发射类型
@property(nonatomic,assign) PaticleFromePositionMode fromPositonMode;


#pragma 初始化
//通过粒子图片名字/数组初始化
-(id)initWithImageName:(NSString *)imageName;
-(id)initWithImageNameArray:(NSArray*)imageArray;
-(id)init;

#pragma 粒子图片

//发射时间
-(void)setEmitterTime:(CGFloat)time;

//开始倒计时
-(void)begin;
@end

#import "PaticleLayer.h"
//粒子系统s
@interface PaticleLayer()
{
    //图片数组
     __strong NSArray* _imageNameArray;
    
    //发射位置模式
    PaticleFromePositionMode _fromPositonMode;
    
    //发射时间
    CGFloat _emitterTime;
}
@end

@implementation PaticleLayer
@dynamic fromPositonMode;

-(id)init
{
    self = [super init];
    if (self) {
        _imageNameArray = [NSMutableArray array];
        [self DefaultSetting];
    }
    return self;
}

-(id)initWithImageName:(NSString *)imageName
{
    self = [super init];
    if (self) {
        _imageNameArray = @[imageName];
        [self DefaultSetting];
    }
    return self;
}

-(id)initWithImageNameArray:(NSArray *)imageArray
{
    self = [super init];
    if (self) {
        _imageNameArray = imageArray;
        [self DefaultSetting];
    }
    return self;
}

-(void)setFromPositonMode:(PaticleFromePositionMode)fromPositonMode
{
    switch (fromPositonMode) {
        case PaticleFromePositionModeNone:
            break;
        case PaticleFromePositionModeCenter:
            [self setEmitterPosition:CGPointMake(320/2.0f,(480+(IPhone5?88:0))/2)];
            break;
        case PaticleFromePositionModeTop:
            [self setEmitterPosition:CGPointMake(320/2.0f,30)];
            break;
        case  PaticleFromePositionModeBottom:
            [self setEmitterPosition:CGPointMake(320/2.0f,(480+(IPhone5?88:0))-30)];
            break;
        default:
            break;
    }
    _fromPositonMode = fromPositonMode;
}

-(PaticleFromePositionMode)fromPositonMode
{
    return _fromPositonMode;
}

-(void)setEmitterTime:(CGFloat)time
{
    _emitterTime = time;
}

//渐渐消失
-(void)fade
{
    CABasicAnimation* fade = [CABasicAnimation animationWithKeyPath:@"opacity"];
    fade.duration = 1.0;
    fade.fromValue = @1.0;
    fade.toValue = @0.0;
    [self addAnimation:fade forKey:@"fade"];
    [NSTimer scheduledTimerWithTimeInterval:0.9 target:self selector:@selector(removeFromSuperlayer) userInfo:nil repeats:NO];
}

//默认设置
-(void)DefaultSetting
{
    //设置出现时间为永远
    [self setEmitterTime:-1.0f];
    
    //设置在中间发射
    [self setFromPositonMode:PaticleFromePositionModeCenter];
    //设置发射尺寸为全屏幕
    [self setEmitterSize:CGSizeMake(320*2.0, 0)];
    //设置发射模式
    [self setEmitterMode:kCAEmitterLayerOutline];
    //设置发射形状，默认圆形
    [self setEmitterShape:kCAEmitterLayerLine];
    
    //设置阴影透明度
    [self setShadowOpacity:1.0];
    //设置半径
    [self setShadowRadius:0.0];
    //
    [self setShadowOffset:CGSizeMake(0.0, 1.0)];
    //
    [self setShadowColor:[[UIColor whiteColor]CGColor]];
    //
    [self setSeed:arc4random()%30+1];
    //跟粒子
    CAEmitterCell* rootCell = [CAEmitterCell emitterCell];
    [rootCell setBirthRate:5.0];
    [rootCell setVelocity:0];
    [rootCell setLifetime:0.35];
    //Cells
    NSArray* children = [self getImageArray];
    if (rootCell) {
        [rootCell setEmitterCells:children];
        [self setEmitterCells:@[rootCell]];
    }
    else
    {
        [self setEmitterCells:children];
    }
}

-(CAEmitterCell *)createCellWithImage:(UIImage *)image{
    CAEmitterCell *cellLayer = [CAEmitterCell emitterCell];
    cellLayer.birthRate= 5.0;
    cellLayer.lifetime= 5.0;
cellLayer.velocity= -100;// falling down slowly
cellLayer.velocityRange = 0;
cellLayer.yAcceleration = 2;
    cellLayer.emissionRange = 0.5 * M_PI;// some variation in angle
    cellLayer.spinRange= 0.25 * M_PI;// slow spin
    
    cellLayer.contents= (id)[image CGImage];
    cellLayer.color= [[UIColor colorWithRed:0.600 green:0.658 blue:0.743 alpha:1.000] CGColor];
    
    return cellLayer;
}

-(NSArray*)getImageArray
{
    NSMutableArray* array = [NSMutableArray array];
    for (NSString* imageName in _imageNameArray) {
        UIImage* image = [UIImage imageNamed:imageName];
        if (image) {
            CAEmitterCell* cell = [self createCellWithImage:image];
            [array addObject:cell];
        }
    }
    return array;
}

-(void)begin
{
    if (_emitterTime > 0) {
        [NSTimer scheduledTimerWithTimeInterval:_emitterTime target:self selector:@selector(fade) userInfo:nil repeats:NO];
    }
}

 


ViewController

-(IBAction)Render
:(id)sender
{
    PaticleLayer* layer = [[PaticleLayer alloc]initWithImageName:@"birthday.png"];
    [layer setEmitterShape:kCAEmitterLayerLine];
    [layer setEmitterTime:10.0];
    [self.view.layer addSublayer:layer];
    [layer begin];
}