基本动作
基本动作通常都是单一的动作,用来完成一个简单的目标。下面通过简单的示例来介绍常见的基本动作。
移动
使用 MoveTo
MoveBy
完成节点对象在一个设置的时间后移动。
auto mySprite = Sprite::create("mysprite.png");
// Move a sprite to a specific location over 2 seconds.
auto moveTo = MoveTo::create(2, Vec2(50, 0));
mySprite->runAction(moveTo);
// Move a sprite 50 pixels to the right, and 0 pixels to the top over 2 seconds.
auto moveBy = MoveBy::create(2, Vec2(50, 0));
mySprite->runAction(moveBy);
旋转
使用 RotateTo
RotateBy
完成节点对象在一个设置的时间后顺时针旋转指定角度。
auto mySprite = Sprite::create("mysprite.png");
// Rotates a Node to the specific angle over 2 seconds
auto rotateTo = RotateTo::create(2.0f, 40.0f);
mySprite->runAction(rotateTo);
// Rotates a Node clockwise by 40 degree over 2 seconds
auto rotateBy = RotateBy::create(2.0f, 40.0f);
mySprite->runAction(rotateBy);
缩放
使用 ScaleBy
ScaleTo
完成节点对象的比例缩放。
auto mySprite = Sprite::create("mysprite.png");
// Scale uniformly by 3x over 2 seconds
auto scaleBy = ScaleBy::create(2.0f, 3.0f);
mySprite->runAction(scaleBy);
// Scale X by 5 and Y by 3x over 2 seconds
auto scaleBy = ScaleBy::create(2.0f, 3.0f, 3.0f);
mySprite->runAction(scaleBy);
// Scale to uniformly to 3x over 2 seconds
auto scaleTo = ScaleTo::create(2.0f, 3.0f);
mySprite->runAction(scaleTo);
// Scale X to 5 and Y to 3x over 2 seconds
auto scaleTo = ScaleTo::create(2.0f, 3.0f, 3.0f);
mySprite->runAction(scaleTo);
淡入淡出
使用 FadeIn
FadeOut
完成节点对象的淡入,淡出。 FadeIn
修改节点对象的透明度属性,从完全透明到完全不透明,FadeOut
相反。
auto mySprite = Sprite::create("mysprite.png");
// fades in the sprite in 1 seconds
auto fadeIn = FadeIn::create(1.0f);
mySprite->runAction(fadeIn);
// fades out the sprite in 2 seconds
auto fadeOut = FadeOut::create(2.0f);
mySprite->runAction(fadeOut);
色彩混合
使用 TintTo
TintBy
,将一个实现了 NodeRGB
协议的节点对象进行色彩混合。
auto mySprite = Sprite::create("mysprite.png");
// Tints a node to the specified RGB values
auto tintTo = TintTo::create(2.0f, 120.0f, 232.0f, 254.0f);
mySprite->runAction(tintTo);
// Tints a node BY the delta of the specified RGB values.
auto tintBy = TintBy::create(2.0f, 120.0f, 232.0f, 254.0f);
mySprite->runAction(tintBy);
帧动画
使用 Animate
对象可以很容易的通过每隔一个短暂时间进行图像替代的方式,实现一个翻页效果。下面是一个例子:
auto mySprite = Sprite::create("mysprite.png");
// now lets animate the sprite we moved
Vector<SpriteFrame*> animFrames;
animFrames.reserve(12);
animFrames.pushBack(SpriteFrame::create("Blue_Front1.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Front2.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Front3.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Left1.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Left2.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Left3.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Back1.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Back2.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Back3.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Right1.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Right2.png", Rect(0,0,65,81)));
animFrames.pushBack(SpriteFrame::create("Blue_Right3.png", Rect(0,0,65,81)));
// create the animation out of the frames
Animation* animation = Animation::createWithSpriteFrames(animFrames, 0.1f);
Animate* animate = Animate::create(animation);
// run it and repeat it forever
mySprite->runAction(RepeatForever::create(animate));
变速运动
变速动作可以让节点对象具有加速度,产生平滑同时相对复杂的动作,所以可以用变速动作来模仿一些物理运动,这样比实际使用物理引擎的性能消耗低,使用起来也简单。当然你也可以将变速动作应用到动画菜单和按钮上,实现你想要的效果。
Cocos2d-x 支持上图中的大部分变速动作,实现起来也很简单。我们来看个例子,一个精灵从屏幕顶部落下然后不断跳动:
// create a sprite
auto mySprite = Sprite::create("mysprite.png");
// create a MoveBy Action to where we want the sprite to drop from.
auto move = MoveBy::create(2, Vec2(200, dirs->getVisibleSize().height -
newSprite2->getContentSize().height));
// create a BounceIn Ease Action
auto move_ease_in = EaseBounceIn::create(move->clone() );
auto move_ease_in_back = move_ease_in->reverse();
// create a delay that is run in between sequence events
auto delay = DelayTime::create(0.25f);
// create the sequence of actions, in the order we want to run them
auto seq1 = Sequence::create(move_ease_in, delay, move_ease_in_back,
delay->clone(), nullptr);
// run the sequence and repeat forever.
mySprite->runAction(RepeatForever::create(seq1));
复杂的动作很难在这样的文本里表示,要是看效果的话最好去运行一下本指南的 代码示例,或者运行引擎代码的测试项目 cpp-tests
,在子菜单 3:Actions - Basic
中有基本的动作效果展示。
运行测试项目的方法,参考本文档的 环境搭建 章节 .