Simple application to load an osg model and take a screenshot of it.

osgscreenshot.cpp

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2010 Robert Osfield
 *
 * This application is open source and may be redistributed and/or modified
 * freely and without restriction, both in commercial and non commercial 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 <osgDB/WriteFile>
#include <osgUtil/Optimizer>
#include <osgDB/FileNameUtils>

#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>

#include <osgGA/TrackballManipulator>

#include <iostream>
#include <stdint.h>


class WriteToFileCaptureOperation : public osgViewer::ScreenCaptureHandler::CaptureOperation
{
public:

    WriteToFileCaptureOperation(const std::string& filename):
      _filename( filename )
    {
    }

    virtual void operator()(const osg::Image& image, const unsigned int context_id)
    {
        osgDB::writeImageFile(image, _filename );
    }

    std::string _filename;
};



int main(int argc, char** argv)
{
    // use an ArgumentParser object to manage the program arguments.
    osg::ArgumentParser arguments(&argc,argv);

    arguments.getApplicationUsage()->setApplicationName(arguments.getApplicationName());
    arguments.getApplicationUsage()->setDescription(arguments.getApplicationName()+" is the standard OpenSceneGraph example which loads and visualises 3d models.");
    arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] filename ...");
    arguments.getApplicationUsage()->addCommandLineOption("--image <filename>","Load an image and render it on a quad");
    arguments.getApplicationUsage()->addCommandLineOption("--dem <filename>","Load an image/DEM and render it on a HeightField");
    arguments.getApplicationUsage()->addCommandLineOption("--login <url> <username> <password>","Provide authentication information for http file access.");
    arguments.getApplicationUsage()->addCommandLineOption("-p <filename>","Play specified camera path animation file, previously saved with 'z' key.");
    arguments.getApplicationUsage()->addCommandLineOption("--speed <factor>","Speed factor for animation playing (1 == normal speed).");
    arguments.getApplicationUsage()->addCommandLineOption("--device <device-name>","add named device to the viewer");

    osgViewer::Viewer viewer(arguments);

    unsigned int helpType = 0;
    if ((helpType = arguments.readHelpType()))
    {
        arguments.getApplicationUsage()->write(std::cout, helpType);
        return 1;
    }

    // report any errors if they have occurred when parsing the program arguments.
    if (arguments.errors())
    {
        arguments.writeErrorMessages(std::cout);
        return 1;
    }

    if (arguments.argc()<=1)
    {
        arguments.getApplicationUsage()->write(std::cout,osg::ApplicationUsage::COMMAND_LINE_OPTION);
        return 1;
    }

    viewer.setCameraManipulator(new osgGA::TrackballManipulator());

    std::string screenCaptureFilename = "screen_shot.jpg";
    while(arguments.read("--screenshot", screenCaptureFilename)) {}

    osg::ref_ptr<osgViewer::ScreenCaptureHandler::CaptureOperation> writeFile = new WriteToFileCaptureOperation(screenCaptureFilename);
    osg::ref_ptr<osgViewer::ScreenCaptureHandler> screenCaptureHandler = new osgViewer::ScreenCaptureHandler(writeFile.get());



    // add the screen capture handler
    viewer.addEventHandler(screenCaptureHandler);

    // load the data
    osg::ref_ptr<osg::Node> loadedModel = osgDB::readNodeFiles(arguments);
    if (!loadedModel)
    {
        std::cout << arguments.getApplicationName() <<": No data loaded" << std::endl;
        return 1;
    }

    // any option left unread are converted into errors to write out later.
    arguments.reportRemainingOptionsAsUnrecognized();

    // report any errors if they have occurred when parsing the program arguments.
    if (arguments.errors())
    {
        arguments.writeErrorMessages(std::cout);
        return 1;
    }

    viewer.setSceneData( loadedModel.get() );

    viewer.realize();

    while (!viewer.done())
    {
        screenCaptureHandler->setFramesToCapture(1);
        screenCaptureHandler->captureNextFrame(viewer);
        viewer.frame();
        screenCaptureHandler->stopCapture();
        return 0;
    }
    return 0;
}