cocos2d－基本概念(3)-Actions: Ease 缓冲动作

Actions: Ease

　　ease 不知道怎么翻译，暂时翻译成缓冲操作吧。这个chapter大概的意思就是对移动等动作进行封装路线的变化，或者是从原来的在总的持续时间不变的前提下，变成了非匀速的运动。需要说名的一点就是，这个wiki里面提到的部分内容，现在最新版本的cocos2d里面已经找不到了，函数的说明变了。。。对于找不到的，暂时不翻译，反正也比较简单，照猫画虎把。哈哈。

　　缓冲操作是一个特殊的复杂操作，可以改变inner 动作的时间。在Flash里面，它们经常被称作Tweening 或者Easing 动作。

　　它们虽然改变了运动的速度，但是并没有改变总体时间，如果整个的action持续5秒钟，那么整个的时间仍然会持续5秒钟。　

　　The Ease actions alter the　linearity　of the time.

例如它们可以对inner的action进行加速或者是减速。　

　　这些action可以被分成3类：　

　　In actions: action开始的时候加速

　　Out actions: action结束的时候加速

　　InOut actions: action开始，结束的时候加速

　　For more information about　easing　or　tweening　actions, visit any of these pages:

　　http://hosted.zeh.com.br/tweener/docs/en-us/misc/transitions.html

　　http://www.robertpenner.com/easing/easing_demo.html

　　Ease actions

这些内部的action是按着如下进行加速的:

-(void)　update:(ccTime)　t　
{　
　　[inner　update:　powf(t,rate)];　
}

rate 这个参数就是增加的速率

　　以下举了几个例子说明的分别的动作的开始，结束，和开始或者结束的时候加速。　

　　Example:

//　acceleration　at　the　beginning
　　　　　　　　id　action　=　[MoveTo　actionWithDuration:2　position:ccp(100,100)];
　id　ease　=　[EaseIn　actionWithAction:action　rate:2];
　[sprite　runAction:　ease];
　
　//　acceleration　at　the　end
　id　action　=　[MoveTo　actionWithDuration:2　position:ccp(100,100)];
　id　ease　=　[EaseIn　actionWithAction:action　rate:2];
　[sprite　runAction:　ease];
　
　//　acceleration　at　the　beginning　/　end
　id　action　=　[MoveTo　actionWithDuration:2　position:ccp(100,100)];
　id　ease　=　[EaseInOut　actionWithAction:action　rate:2];
　[sprite　runAction:　ease];

EaseExponential actions 指数缓冲动作

EaseExponentialIn

　　EaseExponentialOut

　　EaseExponentialInOut

　　EaseSine actions 塞因缓冲

     

　　EaseSineIn

　　EaseSineOut

　　EaseSineInOut

　　接下来的几个Ease的action，在最新版本的cocos2d里面找不到了，貌似已经干掉了。不理解了。。可以我从xcode拿出来的code，就知道了，以下的这几个关键字已经不变色了。。

就剩下一个rate的了。

　　[EaseRateAction actionWithAction:<#(IntervalAction *)action#> rate:<#(float)rate#>];　

　　EaseElastic actions 弹性缓冲

These actions alters the time simulating an elastic. Elastic actions will use　time　values greater than 1 and lower than 0, so the inner action should be prepared to handle this special values.

　　Also some values will be triggered more than once (this function is not bijective), so again, the　inner　action should be prepared to handle this values. Simple actions like　MoveBy,　ScaleBy,　RotateBy　work OK with　EaseElastic　actions, but the　Sequence　or　Spawnactions might have unexpected results.

　　Available since v0.8.2

　　Available elastic actions:

　　EaseElasticIn

　　EaseElasticOut

　　EaseElasticInOut

　　Examples:

//　'period'　is　how　elastic　is　the　action.
　//　recommended　values:　between　0.3　and　0.45
　
　//　Elastic　at　the　beginning
　id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[EaseElasticIn　actionWithAction:move　period:0.3f];
　[sprite　runAction:　action];
　
　//　Elastic　at　the　end
　id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[EaseElasticOut　actionWithAction:move　period:0.3f];
　[sprite　runAction:　action];
　
　//　Elastic　at　the　beginning　and　at　the　end
　id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[EaseElasticInOut　actionWithAction:move　period:0.3f];
　[sprite　runAction:　action];

EaseBounce actions 跳跃缓冲

EaseBounce actions simulates a bouncing effect.

　　Some　time　values will be triggered more than once (this function is not bijective), so the　inner　action should be prepared to handle this values. Simple actions like　MoveBy,　ScaleBy,　RotateBy　work OK with　EaseBounce　actions, but the　Sequence　or　Spawn　actions might have unexpected results.

　　Available since v0.8.2

　　Available bounce actions:

　　EaseBounceIn

　　EaseBounceOut

　　EaseBounceInOut

　　Examples:

//　Bounce　at　the　beginning
　id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[EaseBounceIn　actionWithAction:move];
　[sprite　runAction:　action];
　
　//　Bounce　at　the　end
　id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[EaseBounceOut　actionWithAction:move];
　[sprite　runAction:　action];
　
　//　Bounce　at　the　beginning　and　at　the　end
　id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[EaseBounceInOut　actionWithAction:move];
　[sprite　runAction:　action];

EaseBack actions

　Some　time　values will be triggered more than once (this function is not bijective), so the　inner　action should be prepared to handle this values. Simple actions like　MoveBy,　ScaleBy,　RotateBy　work OK with　EaseBack　actions, but the　Sequence　or　Spawn　actions might have unexpected results.

　　Available since v0.8.2

　　Available bounce actions:

　　EaseBackIn

　　EaseBackOut

　　EaseBackInOut

　　Examples:

//　Back　at　the　beginning
　id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[EaseBackIn　actionWithAction:move];
　[sprite　runAction:　action];
　
　//　Back　at　the　end
　id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[EaseBackOut　actionWithAction:move];
　[sprite　runAction:　action];
　
　//　Back　at　the　beginning　and　at　the　end
　id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[EaseBackInOut　actionWithAction:move];
　[sprite　runAction:　action];

　Actions: Speed

　　Speed action

　　The　Speed　action modifies the duration of the inner action.

id　move　=　[MoveBy　actionWithDuration:3　position:ccp(350,0)];
　id　action　=　[Speed　actionWithAction:　move　speed:1.0f];　　　//　no　speed　modification
　
　//　but　you　can　modify　the　speed　later
　[action　setSpeed:　2.5f];　//　speed　is　2.5　faster
　
　[action　setSpeed:　0.5f];　//　speed　is　0.5　faster　(it　means　2　times　slower)

　出处：http://alexliu.cnblogs.com/