cocos2d-x实现简易屏幕截图功能

在cocos2d-x开发包的test程序中有了截屏的例子，根据这个再加了一点内容：可以随意截取屏幕的某个部分，之后保存图片，两种格式，图片也能显示在屏幕。

http://download.csdn.net/detail/xexiyong/5720369

void HelloWorld::ccTouchesBegan(CCSet* pTouches, CCEvent* pEvent) {CCSetIterator kIterator = pTouches->begin();CCTouch* pTouch = (CCTouch*)(*kIterator);//按下触屏时记录开始触屏点m_kBeginPos = pTouch->locationInView( pTouch->view() );m_kBeginPos = CCDirector::sharedDirector()->convertToGL( m_kBeginPos );}

记录开始触屏的点，然后，记录离开触屏的点，经过计算：

void HelloWorld::ccTouchesEnded(CCSet* pTouches,CCEvent* pEvent){CCSetIterator kIterator = pTouches->begin();CCTouch* pTouch = (CCTouch*)(*kIterator);m_kEndPos = pTouch->locationInView( pTouch->view() );m_kEndPos = CCDirector::sharedDirector()->convertToGL( m_kEndPos );//针对开始点与结束点的计算,得到定制的矩形CRectMake(m_kBeginPos,m_kEndPos);CCSize size = CCDirector::sharedDirector()->getWinSize();//定义一个屏幕大小的渲染纹理CCRenderTexture* pScreen = CCRenderTexture::renderTextureWithWidthAndHeight(size.width,size.height);//获得当前的场景指针CCScene* pCurScene = CCDirector::sharedDirector()->getRunningScene();//渲染纹理开始捕捉pScreen->begin();//当前场景参与绘制pCurScene->visit();//结束捕捉pScreen->end(false);//保存为png(经过裁切的)pScreen->saveBuffer(kCCImageFormatPNG, "Print.png",m_kRect.origin.x, m_kRect.origin.y,m_kRect.size.width, m_kRect.size.height);//保存为jpg，经过裁切的pScreen->saveBuffer(kCCImageFormatJPG,"Print.jpg",m_kRect.origin.x, m_kRect.origin.y,m_kRect.size.width, m_kRect.size.height);//得到该渲染纹理，将该纹理转为精灵经过裁切显示出来CCSprite* pTempImage = CCSprite::spriteWithTexture( (pScreen->getSprite())->getTexture(),m_kRect);pTempImage->setPosition(ccp(0,0));//Y翻转pTempImage->setFlipY(true);addChild(pTempImage,1);//结束且释放CC_SAFE_DELETE(pScreen);}

其中，CRectMake函数作用是利用开始点与结束点算出矩形的宽高和基本点，以供文件生成和精灵显示 使用。

 

void HelloWorld::CRectMake(CCPoint point1,CCPoint point2){CCPoint kOriginPoint;if (point1.x < point2.x){if (point1.y < point2.y){kOriginPoint.x = point1.x;kOriginPoint.y = point2.y;} else{kOriginPoint = point1;}} else{if (point1.y < point2.y){kOriginPoint = point2;} else{kOriginPoint.x = point2.x;kOriginPoint.y = point1.y;}}//至此确定左上角点(是左下角点，cocos2d以左下为基准)m_kRect = CCRect(kOriginPoint.x,kOriginPoint.y - abs(point1.y - point2.y),abs(point1.x - point2.x),abs(point1.y - point2.y));}

最终效果很生硬。大家去优化。