使用C++进行Cocos2d-x游戏开发入门过程中的要点解析

3.组合效果(将2的矩形改成圆,再加上图片)

让我们先看这张图片,是不是很棒?右下角黄色矩形区域是高亮的,在配上图片说明,很不错的效果!

让我们来实现类似的效果吧,用到的资源:

//创建cliper
CCClippingNode* pClip=CCClippingNode::create();
pClip->setInverted(true);
addChild(pClip);
//添加底板
CCLayerColor* pColor=CCLayerColor::create(ccc4(0,0,0,200));
pClip->addChild(pColor);

//绘制圆形区域
static ccColor4F green = {0, 1, 0, 1};//顶点颜色,这里我们没有实质上没有绘制,所以看不出颜色
float fRadius=55.0f;//圆的半径
const int nCount=100;//圆形其实可以看做正多边形,我们这里用正100边型来模拟园
const float coef = 2.0f * (float)M_PI/nCount;//计算每两个相邻顶点与中心的夹角
static CCPoint circle[nCount];//顶点数组
for(unsigned int i = 0;i <nCount; i++) {
 float rads = i*coef;//弧度
 circle[i].x = fRadius * cosf(rads);//对应顶点的x
 circle[i].y = fRadius * sinf(rads);//对应顶点的y
}
CCDrawNode *pStencil=CCDrawNode::create();
pStencil->drawPolygon(circle, nCount, green, 0, green);//绘制这个多边形!

//动起来
pStencil->runAction(CCRepeatForever::create(CCSequence::createWithTwoActions(CCScaleBy::create(0.05f, 0.95f),
 CCScaleTo::create(0.125f, 1))));
pStencil->setPosition(ccp(visibleSize.width/2 + origin.x, visibleSize.height/2 + origin.y));

//设这模板
pClip->setStencil(pStencil);

//添加圆和手的图片
CCSprite*pCircle=CCSprite::create("circle.png");
pCircle->setPosition(ccp(visibleSize.width/2 + origin.x, visibleSize.height/2 + origin.y));
pCircle->runAction(CCRepeatForever::create(CCSequence::createWithTwoActions(CCScaleBy::create(0.05f, 0.95f),
 CCScaleTo::create(0.125f, 1))));
addChild(pCircle);

CCSprite* pHand=CCSprite::create("hand.png");
pHand->setAnchorPoint(ccp(0.0f,1.0f));
pHand->setPosition(ccp(pCircle->getContentSize().width/2,pCircle->getContentSize().height/2));
pCircle->addChild(pHand);