cocos2dx截整屏、截部分屏

我的环境是cocos2dx 2.x的版本

【CCRenderTexture】

CCRenderTexture这个动态纹理类，顾名思义就是可以动态创建纹理图片。

屏幕截图主要步骤：

> 开始截图：render->begin();

> 遍历场景：scene->visit();

> 结束截图：render->end();

> 保存截图：render->saveToFile(string& filename, Image::Format format);

其中Image::Format为图片格式，可以保存为PNG、或JPG两种格式。

即：Image::Format::PNG、Image::Format::JPG。

首先是截整个屏幕（CCDirector.cpp中）：

saveToDCIM函数，找个目录，然后找到一个没用过的名字开始saveScreenShot

 1 void CCDirector::saveToDCIM()
 2 {
 3     char bufferName[256];
 4
 5     for (int i = 0;i<999999;i++)
 6     {
 7         std:string filedir = "";
 8 #if CC_TARGET_PLATFORM == CC_PLATFORM_ANDROID
 9         filedir = std::string(SDKInterface::getExternalStoragePath())  +"/Screenshots";
10 #else
11         filedir = CCFileUtils::sharedFileUtils()->getWritablePath() +"/Screenshots";
12 #endif
13         memset(bufferName,0,sizeof(bufferName));
14         sprintf(bufferName,"/SCREENSHOT_%d.png",i);
15         std::string filename = filedir + std::string(bufferName);
16         if(!CCFileUtils::sharedFileUtils()->isFileExist(filename))
17         {
18             CCLog("ScreenShoot");
19             createDirectory(filedir.c_str());
20             saveScreenshot(filename);
21             return;
22         }
23     }
24 }

这是实际干活的函数：

 1 void CCDirector::saveScreenshot( const std::string& fileName)
 2 {
 3     CCScene* temp = CCDirector::sharedDirector()->getRunningScene();
 4     if (temp)
 5     {
 6         CCSize winSize = CCDirector::sharedDirector()->getWinSize();
 7         CCRenderTexture* rt = CCRenderTexture::create(winSize.width, winSize.height);
 8         rt->begin();
 9         temp->visit();
10         rt->end();
11         rt->saveToFile(fileName.c_str());
12         CCLog(fileName.c_str());
13     }
14 }

然后是截取屏幕的某一个部分，cocos2dx 3.x的版本里可以直接用这个函数：

2.x版本的怎么办呢？用得到的全屏截图rt的一部分RECT创建Sprite，然后在visit该Sprite，获得第二张截图rt2（比较懒，肯定不是最好的方法，欢迎指点）：

 1 void CCDirector::renderTexturePartImpl(int x, int y, int width, int height, const std::string& fileName)
 2 {
 3     CCScene* temp = CCDirector::sharedDirector()->getRunningScene();
 4     if (temp)
 5     {
 6         CCSize winSize = CCDirector::sharedDirector()->getWinSize();
 7         CCRenderTexture* rt = CCRenderTexture::create(winSize.width, winSize.height);
 8         rt->beginWithClear(0,0,0,0,0);
 9         temp->visit();
10         rt->endToLua();
11
12         CCRenderTexture* rt2 = CCRenderTexture::create(width, height);
13         CCSprite* spr = CCSprite::createWithTexture(rt->getSprite()->getTexture(), CCRect(x, y, width, height));
14         spr->setAnchorPoint(CCPoint(0,0));
15         spr->setPosition(CCPoint(0,0));
16         spr->setFlipY(true);
17         rt2->beginWithClear(0,0,0,0,0);
18         spr->visit();
19         rt2->endToLua();
20         rt2->saveToFile(fileName.c_str());
21         CCLog(fileName.c_str());
22     }
23 }