OSG控制帧率的方法

osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer;

osg::ref_ptr<osg::Node> node;

//申请一个定时器

osg::Timer* timer = new osg::Timer;

osg::Timer_t start_frame_time = 0;

osg::Timer_t end_frame_time = 0;

float start_time;

float end_time;

//控制帧率使用的睡眠时间

float sleep_time = 0.0;

float last_sleep_time = 0.0;

//每帧的实际使用时间

float current_time = 0.0;

//每帧控制法

//float per_start_time = 0.0;

//float per_end_time = 0.0;

//计算帧率

int counts = 0;

//得到一个tick值为多少second

std::cout << timer->getSecondsPerTick()<<std::endl;

//start_time = timer->tick();

start_time = viewer->elapsedTime();

timer->setStartTick();

node = osgDB::readNodeFile("glider.osg");

std::cout<<"方法一：读取模型的时间为:"<<timer->time_s()<<std::endl;

//end_time = timer->tick();

end_time = viewer->elapsedTime();

std::cout<<"方法二：读取模型的时间为:"<<end_time - start_time<<std::endl;

//添加帮助事件

viewer->addEventHandler(new PrintName);

viewer->addEventHandler(new osgViewer::HelpHandler);

viewer->addEventHandler(new osgViewer::StatsHandler);

viewer->addEventHandler(new osgViewer::WindowSizeHandler);

viewer->addEventHandler(new osgViewer::ScreenCaptureHandler);

viewer->setSceneData(node);

viewer->setCameraManipulator(new osgGA::TrackballManipulator());

while(!viewer->done())

{

//per_start_time = timer->tick();

if(counts == 0)

{

start_frame_time = timer->tick();

}

counts++;

viewer->frame();

//per_end_time = timer->tick();

//sleep_time = 1/35.0 - timer->delta_s(per_start_time, per_end_time);

if(sleep_time < 0)

{

sleep_time = 0.0;

}

OpenThreads::Thread::microSleep(sleep_time*1000000);

//last_sleep_time = sleep_time;

if(counts == 3)

{

//限制帧率为35

counts = 0;

end_frame_time = timer->tick();

std::cout<<"当前帧速为: " << 3/timer->delta_s(start_frame_time, end_frame_time)<<std::endl;

sleep_time = sleep_time + 1.0/35.0 - timer->delta_s(start_frame_time, end_frame_time)/3;

if(sleep_time < 0)

sleep_time = 0;

}

转载地址：http://blog.sina.com.cn/s/blog_48ed03c801018blt.html