OpenSceneGraph/examples/osgdatabaserevisions/osgdatabaserevisions.cpp
Robert Osfield dd996a3289 Introduced CMake option OSG_PROVIDE_READFILE option that defaults to ON, but when switched to OFF disables the building of the osgDB::read*File() methods,
forcing users to use osgDB::readRef*File() methods.  The later is preferable as it closes a potential threading bug when using paging databases in conjunction
with the osgDB::Registry Object Cache.  This threading bug occurs when one thread gets an object from the Cache via an osgDB::read*File() call where only
a pointer to the object is passed back, so taking a reference to the object is delayed till it gets reassigned to a ref_ptr<>, but at the same time another
thread calls a flush of the Object Cache deleting this object as it's referenceCount is now zero.  Using osgDB::readREf*File() makes sure the a ref_ptr<> is
passed back and the referenceCount never goes to zero.

To ensure the OSG builds when OSG_PROVIDE_READFILE is to OFF the many cases of osgDB::read*File() usage had to be replaced with a ref_ptr<> osgDB::readRef*File()
usage.  The avoid this change causing lots of other client code to be rewritten to handle the use of ref_ptr<> in place of C pointer I introduced a serious of
templte methods in various class to adapt ref_ptr<> to the underly C pointer to be passed to old OSG API's, example of this is found in include/osg/Group:

    bool addChild(Node* child); // old method which can only be used with a Node*

    tempalte<class T> bool addChild(const osg::ref_ptr<T>& child) { return addChild(child.get()); } // adapter template method

These changes together cover 149 modified files, so it's a large submission. This extent of changes are warrent to make use of the Object Cache
and multi-threaded loaded more robust.



git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@15164 16af8721-9629-0410-8352-f15c8da7e697
2015-10-22 13:42:19 +00:00

160 lines
5.8 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 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 <osgUtil/Optimizer>
#include <osg/CoordinateSystemNode>
#include <osg/Switch>
#include <osgText/Text>
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgGA/TrackballManipulator>
#include <osgGA/FlightManipulator>
#include <osgGA/DriveManipulator>
#include <osgGA/KeySwitchMatrixManipulator>
#include <osgGA/StateSetManipulator>
#include <osgGA/AnimationPathManipulator>
#include <osgGA/TerrainManipulator>
#include <osgGA/SphericalManipulator>
#include <iostream>
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.");
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 0
if (arguments.argc()<=1)
{
arguments.getApplicationUsage()->write(std::cout,osg::ApplicationUsage::COMMAND_LINE_OPTION);
return 1;
}
#endif
// set up the camera manipulators.
{
osg::ref_ptr<osgGA::KeySwitchMatrixManipulator> keyswitchManipulator = new osgGA::KeySwitchMatrixManipulator;
keyswitchManipulator->addMatrixManipulator( '1', "Trackball", new osgGA::TrackballManipulator() );
keyswitchManipulator->addMatrixManipulator( '2', "Flight", new osgGA::FlightManipulator() );
keyswitchManipulator->addMatrixManipulator( '3', "Drive", new osgGA::DriveManipulator() );
keyswitchManipulator->addMatrixManipulator( '4', "Terrain", new osgGA::TerrainManipulator() );
keyswitchManipulator->addMatrixManipulator( '5', "Spherical", new osgGA::SphericalManipulator() );
std::string pathfile;
char keyForAnimationPath = '6';
while (arguments.read("-p",pathfile))
{
osgGA::AnimationPathManipulator* apm = new osgGA::AnimationPathManipulator(pathfile);
if (apm || !apm->valid())
{
unsigned int num = keyswitchManipulator->getNumMatrixManipulators();
keyswitchManipulator->addMatrixManipulator( keyForAnimationPath, "Path", apm );
keyswitchManipulator->selectMatrixManipulator(num);
++keyForAnimationPath;
}
}
viewer.setCameraManipulator( keyswitchManipulator.get() );
}
// add the state manipulator
viewer.addEventHandler( new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()) );
// add the thread model handler
viewer.addEventHandler(new osgViewer::ThreadingHandler);
// add the window size toggle handler
viewer.addEventHandler(new osgViewer::WindowSizeHandler);
// add the stats handler
viewer.addEventHandler(new osgViewer::StatsHandler);
// add the help handler
viewer.addEventHandler(new osgViewer::HelpHandler(arguments.getApplicationUsage()));
// add the record camera path handler
viewer.addEventHandler(new osgViewer::RecordCameraPathHandler);
// add the LOD Scale handler
viewer.addEventHandler(new osgViewer::LODScaleHandler);
// add the screen capture handler
viewer.addEventHandler(new osgViewer::ScreenCaptureHandler);
std::string file = "http://www.openscenegraph.org/data/earth_bayarea/earth.ive";
osgDB::FileCache* fileCache = osgDB::Registry::instance()->getFileCache();
if (fileCache)
{
fileCache->loadDatabaseRevisionsForFile(file);
// fileCache->loadDatabaseRevisionsForFile(file); // test to make sure that repeated loads of same revision file doesn't cause problems
}
// load the data
osg::ref_ptr<osg::Node> loadedModel = osgDB::readRefNodeFile(file);
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;
}
// optimize the scene graph, remove redundant nodes and state etc.
osgUtil::Optimizer optimizer;
optimizer.optimize(loadedModel.get());
viewer.setSceneData( loadedModel.get() );
viewer.realize();
return viewer.run();
}