【转】COCOS2D曲线动作

曲线动作 
曲线动作是在一段时间改变的特殊复合动作。在动画世界里它们经常被称为Tweening或者Easing action。 
这些动作在内部修改动作的速度。但是它们不能修改运行时间。如果一个运行是5秒，那么动作的持续时间就是5秒。 
曲线动作在时间片内改变直线。 
 
比如它们可以加速或者减速内部动作。 
这些动作被声明为3个类型： 
In actions:加速器在动作的开始 
Out actions:加速器在动作的结尾 
InOut actions:加速器在动作的开始和结尾 

关于它的更多内容请访问： 
http://hosted.zeh.com.br/tweener/docs/en-us/misc/transitions.html 
http://www.robertpenner.com/easing/easing_demo.html 

它们加速的方式用公式进行定义： 
-(void)update:(ccTime) t 
{ 
  [innerupdate: powf(t,rate)]; 
} 
变种 
CCEaseIn:加速器在动作的开始； 
CCEaseOut:加速器在动作的结尾； 
CCEaseInOut:加速器在动作的开始和结尾速率实参代表加速器的速率。 
// acceleration at the beginningid 
action = [CCMoveToactionWithDuration:2position:ccp(100,100)]; 
id ease = [CCEaseInactionWithAction:action rate:2]; 
[spriterunAction: ease]; 
// acceleration at the endid 
action = [CCMoveToactionWithDuration:2position:ccp(100,100)]; 
id ease = [CCEaseOutactionWithAction:action rate:2]; 
[spriterunAction: ease]; 
// acceleration at the beginning / endid 
action = [CCMoveToactionWithDuration:2position:ccp(100,100)]; 
id ease = [CCEaseInOutactionWithAction:action rate:2]; 
[sprite runAction: ease]; 
指数型曲线动作 

 
变种： 
CCEaseExponentialIn； 
CCEaseExponentialOut； 
CCEaseExponentialInOut 
id scaleAction = [CCScaleTo actionWithDuration:2.5 scale:.8]; 
id easeAction = [CCEaseExponentialInactionWithAction:scaleAction]; 
[label runAction:easeAction]; 

变种： 
CCEaseSineIn； 
CCEaseSineOut； 
CCEaseSineInOut 

// Sine at the beginning 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseSineInactionWithAction:move]; 
[spriterunAction:action]; 
// Sine at the end 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseSineOutactionWithAction:move]; 
[spriterunAction:action]; 
// Sine at the beginning and at the end 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseSineInOutactionWithAction:move]; 
[sprite runAction:action]; 
心电图型动作： 

 

这些动作在时间片内模仿心电图图形，这个动作使用时间在0～1s内，所以这个内部动作操作这个特殊的值 
这些值要不止一次使用（这个函数不是对象）。所以内部动作准备修改这个值。比如CCMoveBy,CCScaleBy,CCRotateBy等等，但是CCSquence或CCSpawn也许是不期望的结果。 
变种： 
CCEaseElasticIn 
CCEaseElasticOut 
CCEaseElasticInOut 

// 'period' is how elastic is the action. 
// recommended values: between 0.3 and 0.45 
// Elastic at the beginning 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseElasticInactionWithAction:move period:0.3f]; 
[spriterunAction: action]; 
// Elastic at the end 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseElasticOutactionWithAction:move period:0.3f]; 
[spriterunAction: action]; 
// Elastic at the beginning and at the end 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseElasticInOutactionWithAction:move period:0.3f]; 
[sprite runAction: action]; 

股市型： 

 

股市型模拟了一个反弹效果。 
这些要不止一次使用（这个函数不是对象）。所以内部动作应该准备修改这个值。比如CCMoveBy,CCScaleBy,CCRotateBy等等，但是CCSquence或CCSpawn也许是不期望的结果。 
变种： 
CCEaseBounceIn 
CCEaseBounceOut 
CCEaseBounceInOut 
// Bounce at the beginning 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseBounceInactionWithAction:move]; 
[spriterunAction: action]; 
// Bounce at the end 
id move = [CCMoveByactionWithDuration:3 position:ccp(350,0)]; 
id action = [CCEaseBounceOutactionWithAction:move]; 
[spriterunAction: action]; 
// Bounce at the beginning and at the end 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseBounceInOutactionWithAction:move]; 
[sprite runAction: action]; 
返回型： 
这些值要不止一次使用（这个函数不是对象）。所以内部动作应该准备修改这个值。比如CCMoveBy,CCScaleBy,CCRotateBy等等，但是CCSquence或CCSpawn也许是不期望的结果。 
变种： 
CCEaseBackIn 
CCEaseBackOut 
CCEaseBackInOut 
// Back at the beginning 
id move = [CCMoveByactionWithDuration:3 position:ccp(350,0)]; 
id action = [CCEaseBackInactionWithAction:move]; 
[spriterunAction: action]; 
// Back at the end 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseBackOutactionWithAction:move]; 
[spriterunAction: action]; 
// Back at the beginning and at the end 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCEaseBackInOutactionWithAction:move]; 
[sprite runAction: action]; 

加速型： 
CCSpeed动作修改了内部的持续时间 
id move = [CCMoveByactionWithDuration:3position:ccp(350,0)]; 
id action = [CCSpeedactionWithAction: move speed:1.0f];   // no speed modification 
// but you can modify the speed later 
[action setSpeed:2.5f]; // speed is 2.5faster 
[action setSpeed: 0.5f]; //speed is 0.5 faster (it means 2 times slower)