iOS中利用CAEmitterLayer实现粒子动画详解

@property(copy) NSArray *colors 渐变颜色的数组 @property(copy) NSArray *locations 渐变颜色的区间分布，locations的数组长度和color一致，一般不用设置，默认是nil，会平均分布。//[NSArray arrayWithObjects:[NSNumber numberWithFloat:0.0],  //       [NSNumber numberWithFloat:0.3],  //       [NSNumber numberWithFloat:0.8],  //       [NSNumber numberWithFloat:1.0],  //      nil]; @property CGPoint startPoint 映射locations中第一个位置，用单位向量表示，比如（0，0）表示从左上角开始变化。默认值是(0.5,0.0)。@property CGPoint endPoint 映射locations中最后一个位置,用单位向量表示，比如（1，1）表示到右下角变化结束。默认值是(0.5,1.0)。

 //渐变色 CAGradientLayer *gradientLayer = [CAGradientLayer layer]; gradientLayer.frame = self.view.bounds; [self.view.layer addSublayer:gradientLayer]; UIColor *lightColor = [UIColor colorWithRed:40.0 / 255.0 green:150.0 / 255.0 blue:200.0 / 255.0 alpha:1.0]; UIColor *whiteColor = [UIColor colorWithRed:255.0 / 255.0 green:250.0 / 255.0 blue:250.0 / 255.0 alpha:1.0];//可以设置多个colors, gradientLayer.colors = @[(__bridge id)lightColor.CGColor,(__bridge id)whiteColor.CGColor]; //45度变色(由lightColor－>white) gradientLayer.startPoint = CGPointMake(0, 0); gradientLayer.endPoint = CGPointMake(1, 1);

 CAEmitterCell *cell = [[CAEmitterCell alloc] init]; //展示的图片 cell.contents = (__bridge id _Nullable)([UIImage imageNamed:@"white"].CGImage); //每秒粒子产生个数的乘数因子，会和layer的birthRate相乘，然后确定每秒产生的粒子个数 cell.birthRate = 2000; //每个粒子存活时长 cell.lifetime = 5.0; //粒子生命周期范围 cell.lifetimeRange = 0.3; //粒子透明度变化，设置为－0.4，就是每过一秒透明度就减少0.4，这样就有消失的效果,一般设置为负数。 cell.alphaSpeed = -0.2; cell.alphaRange = 0.5; //粒子的速度 cell.velocity = 40; //粒子的速度范围 cell.velocityRange = 20; //周围发射的角度，如果为M_PI*2 就可以从360度任意位置发射 //cell.emissionRange = M_PI*2; //粒子内容的颜色 // cell.color = [[UIColor whiteColor] CGColor];//设置了颜色变化范围后每次产生的粒子的颜色都是随机的 cell.redRange = 0.5; cell.blueRange = 0.5; cell.greenRange = 0.5; //缩放比例 cell.scale = 0.2; //缩放比例范围 cell.scaleRange = 0.02; //粒子的初始发射方向 cell.emissionLongitude = M_PI; //Y方向的加速度 cell.yAcceleration = 70.0; //X方向加速度 // cell.xAcceleration = 20.0; _emitterLayer = [CAEmitterLayer layer]; //发射位置 _emitterLayer.emitterPosition = CGPointMake(SCREEN_WIDTH/2.0, 0); //粒子产生系数，默认为1 _emitterLayer.birthRate = 1; //发射器的尺寸 _emitterLayer.emitterSize = CGSizeMake(SCREEN_WIDTH, 0); //发射的形状 _emitterLayer.emitterShape = kCAEmitterLayerLine; //发射的模式 _emitterLayer.emitterMode = kCAEmitterLayerLine; //渲染模式 _emitterLayer.renderMode = kCAEmitterLayerOldestFirst; _emitterLayer.masksToBounds = NO; //_emitterLayer.zPosition = -1; _emitterLayer.emitterCells = @[cell];//emitterView是自己创建的一个View [self.emitterView.layer addSublayer:_emitterLayer];

CA_EXTERN NSString * const kCAEmitterLayerPoint//点 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerLine//线 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerRectangle//矩形 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerCuboid//立方体 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerCircle//圆形 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerSphere//球形 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);

CA_EXTERN NSString * const kCAEmitterLayerPoints//从发射器中 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerOutline//边缘 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerSurface//表面 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerVolume//中点 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);

CA_EXTERN NSString * const kCAEmitterLayerUnordered//粒子是无序出现的，多个发射源将混合 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerOldestFirst//声明久的粒子会被渲染在最上层 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerOldestLast//年轻的粒子会被渲染在最上层 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerBackToFront//粒子的渲染按照Z轴的前后顺序进行 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);CA_EXTERN NSString * const kCAEmitterLayerAdditive//进行粒子混合 CA_AVAILABLE_STARTING (10.6, 5.0, 9.0, 2.0);