本文的重點在於如何將截圖功能繼承到Cocos2d-x 3.0引擎。
1.集成到Director
這裏選擇把截屏功能繼承到Director中,讓全局的導演來執行截屏功能是一個很好的主意。
void Director::saveScreenshot(const std::string& fileName,const std::function<void(const std::string&)>& callback)
{
Image::Format format;
//進行後綴判斷
if(std::string::npos != fileName.find_last_of(".")){
auto extension = fileName.substr(fileName.find_last_of("."),fileName.length());
if (!extension.compare(".png")) {
format = Image::Format::PNG;
} else if(!extension.compare(".jpg")) {
format = Image::Format::JPG;
} else{
CCLOG("cocos2d: the image can only be saved as JPG or PNG format");
return;
}
} else {
CCLOG("cocos2d: the image can only be saved as JPG or PNG format");
return ;
}
//獲取屏幕尺寸,初始化一個空的渲染紋理對象
auto renderTexture = RenderTexture::create(getWinSize().width, getWinSize().height, Texture2D::PixelFormat::RGBA8888);
//清空並開始獲取
renderTexture->beginWithClear(0.0f, 0.0f, 0.0f, 0.0f);
//遍歷場景節點對象,填充紋理到RenderTexture中
getRunningScene()->visit();
//結束獲取
renderTexture->end();
//保存文件
renderTexture->saveToFile(fileName , format);
//使用schedule在下一幀中調用callback函數
auto fullPath = FileUtils::getInstance()->getWritablePath() + fileName;
auto scheduleCallback = [&,fullPath,callback](float dt){
callback(fullPath);
};
auto _schedule = getRunningScene()->getScheduler();
_schedule->schedule(scheduleCallback, this, 0.0f,0,0.0f, false, "screenshot");
}
2.如何使用saveScreenshot
截屏功能使用起來也很簡單,直接調用saveSecreenshot,其中第一個參數爲文件名(支持png和jpg格式,不帶後綴名默認爲png格式),第二個參數爲回調函數,你可以在回調函數中處理這個文件。void ScreenshotTest::saveImage(Ref *pSender){
static int counter = 0;
char png[20];
sprintf(png, "image-%d.png", counter);
char jpg[20];
sprintf(jpg, "image-%d.jpg", counter);
//截屏後的回調函數,這裏顯示在左下角
auto callback = [&](const std::string& fullPath){
auto sprite = Sprite::create(fullPath);
CCASSERT(sprite!=nullptr, "Failed to create sprite.");
addChild(sprite);
sprite->setScale(0.3f);
sprite->setPosition(Point(40, 40));
sprite->setRotation(counter * 3);
CCLOG("Image saved %s", fullPath.c_str());
};
//調用Director的截屏功能
Director::getInstance()->saveScreenshot(png, callback);
counter++;
}