cocos2d播放雪花

转载自：http://blog.sina.com.cn/s/blog_6e29f5680100vqir.html

-(void) playEffectSnow {
    //使用自带下雪粒子
    CCParticleSnow *particle = [CCParticleSnow node];
    //自定义雪花图片
    particle.texture = [[CCTextureCache sharedTextureCache] addImage:@"snow.png"];
    //粒子总数
    particle.totalParticles = 400;
    //下雪时间 秒
    particle.duration = 3;
    //雪花开始大小    
    particle.startSize = 40;
    //雪花大小浮动
    particle.startSizeVar=20;
    //雪花结束大小
    //particle.endSize = 50;
    //particle.endSizeVar = 30;
    //初始速度    
    particle.speed = 20;
    particle.speedVar = 15;
    //下降速度 y负数表示下落 x负数表示向西吹
    particle.gravity = ccp(-20, -70);
    //每个雪花生命时间
    particle.life = 4.0f;
    particle.lifeVar = 2.0f;
    //particle.position = ccp(240, 320);
    //释放雪花速度
    particle.emissionRate = particle.totalParticles/particle.life;
    //动画完成后自动从上层layer中移除粒子
    particle.autoRemoveOnFinish = YES;
    //释放粒子位置    
    particle.position = (CGPoint) {
        [[CCDirector sharedDirector] winSize].width / 2,
        [[CCDirector sharedDirector] winSize].height + 10
    };
    particle.posVar = ccp( [[CCDirector sharedDirector] winSize].width / 2+50, 0 );
    //添加到layer中   
    [self addChild:particle z:1000];
}