OpenSceneGraph/examples/osgmotionblur/osgmotionblur.cpp
2007-01-11 17:15:04 +00:00

117 lines
3.7 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This application is open source and may be redistributed and/or modified
* freely and without restriction, both in commericial and non commericial applications,
* as long as this copyright notice is maintained.
*
* This application is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*/
#include <osgDB/ReadFile>
#include <osgUtil/Optimizer>
#include <osgViewer/Viewer>
#include <iostream>
class MotionBlurOperation: public osg::GraphicsOperation
{
public:
MotionBlurOperation(double persistence):
osg::GraphicsOperation("MotionBlur",true),
cleared_(false),
persistence_(persistence)
{
}
virtual void operator () (osg::GraphicsContext* gc)
{
double t = gc->getState()->getFrameStamp()->getReferenceTime();
if (!cleared_)
{
// clear the accumulation buffer
glClearColor(0, 0, 0, 0);
glClear(GL_ACCUM_BUFFER_BIT);
cleared_ = true;
t0_ = t;
}
double dt = fabs(t - t0_);
t0_ = t;
// compute the blur factor
double s = powf(0.2, dt / persistence_);
// scale, accumulate and return
glAccum(GL_MULT, s);
glAccum(GL_ACCUM, 1 - s);
glAccum(GL_RETURN, 1.0f);
}
private:
bool cleared_;
double t0_;
double persistence_;
};
int main( int argc, char **argv )
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
// set up the usage document, in case we need to print out how to use this program.
arguments.getApplicationUsage()->setApplicationName(arguments.getApplicationName());
arguments.getApplicationUsage()->setDescription(arguments.getApplicationName()+" is an OpenSceneGraph example that shows how to use the accumulation buffer to achieve a simple motion blur effect.");
arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] filename ...");
arguments.getApplicationUsage()->addCommandLineOption("-h or --help","Display this information");
arguments.getApplicationUsage()->addCommandLineOption("-P or --persistence","Set the motion blur persistence time");
// construct the viewer.
osgViewer::Viewer viewer;
// if user request help write it out to cout.
if (arguments.read("-h") || arguments.read("--help"))
{
arguments.getApplicationUsage()->write(std::cout);
return 1;
}
double persistence = 0.25;
arguments.read("-P", persistence) || arguments.read("--persistence", persistence);
// read the scene from the list of file specified commandline args.
osg::ref_ptr<osg::Node> loadedModel = osgDB::readNodeFiles(arguments);
// if no model has been successfully loaded report failure.
if (!loadedModel)
{
std::cout << arguments.getApplicationName() <<": No data loaded" << std::endl;
return 1;
}
// set the display settings we can to request, OsgCameraGroup will read this.
osg::DisplaySettings::instance()->setMinimumNumAccumBits(8,8,8,8);
// pass the loaded scene graph to the viewer.
viewer.setSceneData(loadedModel.get());
// create the windows and run the threads.
viewer.realize();
osgViewer::Viewer::Windows windows;
viewer.getWindows(windows);
for(osgViewer::Viewer::Windows::iterator itr = windows.begin();
itr != windows.end();
++itr)
{
(*itr)->add(new MotionBlurOperation(persistence));
}
return viewer.run();
}