OpenSceneGraph/examples/osgmotionblur/osgmotionblur.cpp

131 lines
4.4 KiB
C++

/* OpenSceneGraph example, osgmotionblur.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <osgDB/ReadFile>
#include <osgUtil/Optimizer>
#include <osgViewer/Viewer>
#include <iostream>
class MotionBlurOperation: public osg::Operation
{
public:
MotionBlurOperation(double persistence):
osg::Operation("MotionBlur",true),
cleared_(false),
persistence_(persistence)
{
}
virtual void operator () (osg::Object* object)
{
osg::GraphicsContext* gc = dynamic_cast<osg::GraphicsContext*>(object);
if (!gc) return;
double t = gc->getState()->getFrameStamp()->getSimulationTime();
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 not loaded assume no arguments passed in, try use default mode instead.
if (!loadedModel) loadedModel = osgDB::readNodeFile("cow.osg");
// 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();
}