Cocos-2d-x 学习笔记二（Action篇）

Cocos-2d-x学习笔记二

1.Action类

• ActionInterval example:Flipx()
ActionInstant是瞬时动作类，表示瞬间完成，中间没有动画效果，Flipx()就是它的一个例子，当物体走到障碍物时会有一个转向的过程，这可以通过Flipx的动作效果，以下是code:

//创建移动动作ActionInterval *moveto = MoveTo::create(5, Vec2(0, 200));// 创建X轴方向的翻转动作ActionInstant *flipx = FlipX::create(true);ActionInterval *moveback = MoveTo::create(5, Vec2(visibleSize.width, 200));auto player=Sprite::create("player.png");player->setPosition(Point(visibleSize.width/2,200));auto action = Sequence::create(moveto, flipx, moveback, flipx->reverse(), NULL);   player->runAction(action);

• 延时动作
  即之前所提到的MoveBy,MoveTo会在指定时间内完成，中间会有动画效果，本次要将的是如何实现贝塞尔曲线的运动效果,它需要一个起点，终点，控制点，和控制线sample,代码实现如下：

ccBezierConfig beizer;    beizer.controlPoint_1 = Point(200, 300);    beizer.controlPoint_2 = Point(400, 400);    beizer.endPosition = Point(50, 200);    auto beizierAction = BezierTo::create(2.0f,beizer);    auto dog = Sprite::create("player.png");    dog->setPosition(Point(visibleSize.width / 2, 200));    this->addChild(dog);    dog->runAction(beizierAction);

额，后面会讲到一个JumpBy和JumpTo类所以就在这里先介绍一下，其create后面有4个参数，第一个是执行的时间，第二个是一个对象的坐标，代表跳完最后落在的坐标(以原来对象所处位置为原点的相对坐标系)
- ActionEase 缓冲效果
该类有5类运动：指数缓冲，Sine缓冲，弹性缓冲，跳跃缓冲，回震缓冲，每类运动都包含了3个不同时期的变换:In,Out,InOut,(其中in代表开始时加速，out代表结尾时加速)，以下是样例：

ActionInterval *moveto1 = MoveTo::create(5, Vec2(50, 100));ActionInterval *moveto2 = MoveTo::create(5, Vec2(50, 300));ActionInterval *moveto3 = MoveTo::create(5, Vec2(50, 500));auto scene = Director::getInstance()->getRunningScene();auto layer = scene->getChildByTag(1);auto dog1 = layer->getChildByTag(1);auto dog2 = layer->getChildByTag(2);auto dog3 = layer->getChildByTag(3);auto action1 = EaseExponentialIn::create(moveto1);auto action2 = EaseExponentialOut::create(moveto2);auto action3 = EaseExponentialInOut::create(moveto3);dog1->runAction(action1);dog2->runAction(action2);dog3->runAction(action3);    //我在vs上跑的时候为什么先执行第二个函数

• 组合动作
  sequence和spawn在上一次中已经讲过了，所以这次讲一下Repeat和RepeatForever类。repeat类可以指定重复次数。代码示例如下：

  auto jumpto1 = JumpBy::create(3, Vec2(0, 0), 100, 1);auto jumpto2 = JumpBy::create(3, Vec2(0, 0), 100, 1);auto player1 = Sprite::create("player.png");auto player2 = Sprite::create("player.png");player1->setPosition(Point(visibleSize / 3));player1->setPosition(Point(visibleSize * 2 / 3));this->addChild(player1);this->addChild(player2);auto repeatJump = Repeat::create(jumpto1, 5);auto repeatForeverJump = RepeatForever::create(jumpto2);player1->runAction(repeatJump);player2->runAction(repeatForeverJump);

  其实还有一个callfunc类没有写，但是目前还是没有完全搞懂这一个系列的东西的作用到底是啥，所以就先不写了。。。