一、CAEmitterLayer
CAEmitterLayer是QuartzCore提供的粒子引擎, 可用于制作粒子特效。CAEmitterLayer配合CAEmitterCell使用, 它有一个属性emitterCells, 将CAEmitterCell直接添加到该数组中, 即可实现粒子效果。
二、先大致了解下CAEmitterLayer的基本属性
birthRate:粒子产生速度，默认1.0；
emitterCells: 装着CAEmitterCell对象的数组，把粒子放到layer上；
emitterDepth:决定粒子形状的深度
emitterMode:发射模式
emitterPosition:发射位置
emitterShape:发射源的形状;
emitterSize:发射源的尺寸大；
emitterZposition:发射源的z坐标位置；
lifetime:粒子生命周期
renderMode:渲染模式：
scale:粒子的缩放比例：
seed:用于初始化随机数产生的种子
spin:自旋转速度
velocity:粒子速度
三、CAEmitterCell的基本属性
birthRate:这个必须要设置，每秒产生cell数量
alphaRange:一个粒子的颜色alpha值的范围
alphaSpeed:粒子透明度在生命周期内的改变速度
blueRange:一个粒子的颜色blue 能改变的范围
blueSpeed:粒子blue在生命周期内的改变速度
color:粒子的颜色
contents:是个CGImageRef的对象,既粒子要展现的图片
emissionLatitude:发射的z轴方向的角度
emissionLongitude:x-y平面的发射方向
emissionRange:周围发射角度
emitterCells发射的粒子
enabled:粒子是否被渲染
greenrange: 一个粒子的颜色green能改变的范围
greenSpeed:粒子green在生命周期内的改变速度
lifetime:生命周期
lifetimeRange:生命周期范围
magnificationFilter:粒子过滤器放大模式
minificatonFilter:粒子过滤器缩小模式
minificationFilterBias:减小大小的因子
name:粒子的名字
redRange:一个粒子的颜色red 能改变的范围
redSpeed:粒子red在生命周期内的改变速度
scale:缩放比例
scaleRange:缩放比例范围
scaleSpeed:缩放比例速度
spin:粒子旋转角度
spinrange:粒子旋转角度范围
velocity:速度
velocityRange:速度范围
xAcceleration:粒子x方向的加速度分量
yAcceleration:粒子y方向的加速度分量
zAcceleration:粒子z方向的加速度分量
四、实现礼花🎉效果
#import "EmitterVC.h"
@interface EmitterVC ()
@end
@implementation EmitterVC
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor lightGrayColor];
UIButton * test = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 80, 80)];
test.layer.cornerRadius = 40;
test.center = self.view.center;
test.backgroundColor = [UIColor purpleColor];
[test addTarget:self action:@selector(animation2:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:test];
}
- (void)animation2:(UIButton *)btn{
//粒子发射器
CAEmitterLayer *snowEmitter = [CAEmitterLayer layer];
snowEmitter.emitterPosition = CGPointMake(btn.bounds.size.width/2.0, btn.bounds.size.height/2.0);
snowEmitter.emitterSize = btn.bounds.size;
snowEmitter.emitterMode = kCAEmitterLayerOutline;
snowEmitter.emitterShape = kCAEmitterLayerRectangle;
snowEmitter.seed = (arc4random() % 100) + 1;
CAEmitterCell * spark = [CAEmitterCell emitterCell];
spark.birthRate = 30;
spark.velocity = 80;
spark.emissionRange = 2* M_PI;// 360 度
spark.lifetime = 1.0;
spark.contents = (id) [[UIImage imageNamed:@"emitter1"] CGImage];
spark.scaleSpeed = -0.8;
spark.alphaSpeed = -.9;
spark.spin = M_PI_2;
spark.spinRange = M_PI_2;
//粒子发射器
CAEmitterLayer *snowEmitter1 = [CAEmitterLayer layer];
snowEmitter1.emitterPosition = CGPointMake(btn.bounds.size.width/2.0, btn.bounds.size.height/2.0);
snowEmitter1.emitterSize = btn.bounds.size;
snowEmitter1.emitterMode = kCAEmitterLayerOutline;
snowEmitter1.emitterShape = kCAEmitterLayerRectangle;
snowEmitter1.seed = (arc4random() % 100) + 1;
CAEmitterCell * spark1 = [CAEmitterCell emitterCell];
spark1.birthRate = 30;
spark1.velocity = 100;
spark1.emissionRange = 2* M_PI; // 360 度
spark1.lifetime = 1.0;
spark1.contents = (id) [[UIImage imageNamed:@"emitter2"] CGImage];
spark1.scaleSpeed = -0.8;
spark1.alphaSpeed = -.9;
spark1.spin = M_PI_2;
spark1.spinRange = M_PI_2;
// 将粒子添加到粒子发射器上
snowEmitter.emitterCells = [NSArray arrayWithObject:spark];
snowEmitter1.emitterCells = [NSArray arrayWithObject:spark1];
[btn.layer addSublayer:snowEmitter];
[btn.layer addSublayer:snowEmitter1];
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC));
dispatch_time_t popTime2 = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.0 * NSEC_PER_SEC));
__weak typeof(snowEmitter) weakselEmitter = snowEmitter;
__weak typeof(snowEmitter1) weakselEmitter1 = snowEmitter1;
dispatch_after(popTime, dispatch_get_main_queue(), ^{
__strong typeof(weakselEmitter) strongEmitter = weakselEmitter;
__strong typeof(weakselEmitter1) strongEmitter1 = weakselEmitter1;
strongEmitter.birthRate = 0;
strongEmitter1.birthRate = 0;
});
dispatch_after(popTime2, dispatch_get_main_queue(), ^{
__strong typeof(weakselEmitter) strongEmitter = weakselEmitter;
__strong typeof(weakselEmitter1) strongEmitter1 = weakselEmitter1;
[strongEmitter removeFromSuperlayer];
[strongEmitter1 removeFromSuperlayer];
});
}
- (void)animation1{
// Cells spawn in the bottom, moving up
//分为3种粒子，子弹粒子，爆炸粒子，散开粒子
CAEmitterLayer *fireworksEmitter = [CAEmitterLayer layer];
CGRect viewBounds = self.view.layer.bounds;
fireworksEmitter.emitterPosition = CGPointMake(viewBounds.size.width/2.0, viewBounds.size.height);
fireworksEmitter.emitterSize = CGSizeMake(200, 200);
fireworksEmitter.emitterMode = kCAEmitterLayerPoints;
fireworksEmitter.emitterShape = kCAEmitterLayerPoint;
fireworksEmitter.renderMode = kCAEmitterLayerBackToFront;
fireworksEmitter.seed = (arc4random()%100)+1;
// Create the rocket
CAEmitterCell* rocket = [CAEmitterCell emitterCell];
rocket.birthRate = 1.0;
rocket.emissionRange = 0.25 * M_PI; // some variation in angle
rocket.velocity = 380;
rocket.velocityRange = 100;
rocket.yAcceleration = 75;
rocket.lifetime = 1.02; // we cannot set the birthrate < 1.0 for the burst
//星星图片
rocket.contents = (id)[[UIImage imageNamed:@"emitter1"] CGImage];
rocket.scale = 0.2;
rocket.color = [[UIColor redColor] CGColor];
rocket.greenRange = 1.0; // different colors
rocket.redRange = 1.0;
rocket.blueRange = 1.0;
rocket.spinRange = M_PI; // slow spin
// the burst object cannot be seen, but will spawn the sparks
// we change the color here, since the sparks inherit its value
CAEmitterCell* burst = [CAEmitterCell emitterCell];
burst.birthRate = 1.0; // at the end of travel
burst.velocity = 0; //速度为0
burst.scale = 2.5; //大小
burst.redSpeed =-1.5; // shifting
burst.blueSpeed =+1.5; // shifting
burst.greenSpeed =+1.0; // shifting
burst.lifetime = 0.35; //存在时间
// and finally, the sparks
CAEmitterCell* spark = [CAEmitterCell emitterCell];
spark.birthRate = 400;
spark.velocity = 125;
spark.emissionRange = 2* M_PI; // 360 度
spark.yAcceleration = 75; // gravity
spark.lifetime = 3;
//星星图片
spark.contents = (id) [[UIImage imageNamed:@"emitter2"] CGImage];
spark.scaleSpeed =-0.2;
spark.greenSpeed =-0.1;
spark.redSpeed = 0.4;
spark.blueSpeed =-0.1;
spark.alphaSpeed =-0.25;
spark.spin = 2* M_PI;
spark.spinRange = 2* M_PI;
// 3种粒子组合，可以根据顺序，依次烟花弹－烟花弹粒子爆炸－爆炸散开粒子
fireworksEmitter.emitterCells = [NSArray arrayWithObject:rocket];
rocket.emitterCells = [NSArray arrayWithObject:burst];
burst.emitterCells = [NSArray arrayWithObject:spark];
[self.view.layer addSublayer:fireworksEmitter];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
四、效果图
gif5新文件(1).gif
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