OpenSceneGraph/examples/osgviewerGLUT/osgviewerGLUT.cpp
Robert Osfield 6a67be2e32 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/branches/OpenSceneGraph-3.4@15165 16af8721-9629-0410-8352-f15c8da7e697
2015-10-22 14:14:53 +00:00

147 lines
4.2 KiB
C++

/* OpenSceneGraph example, osgviewerGlut.
*
* 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.
*/
// (C) 2005 Mike Weiblen http://mew.cx/ released under the OSGPL.
// Simple example using GLUT to create an OpenGL window and OSG for rendering.
// Derived from osgGLUTsimple.cpp and osgkeyboardmouse.cpp
#include <osg/Config>
#if defined(_MSC_VER) && defined(OSG_DISABLE_MSVC_WARNINGS)
// disable warning "glutCreateMenu_ATEXIT_HACK' : unreferenced local function has been removed"
#pragma warning( disable : 4505 )
#endif
#include <iostream>
#ifdef WIN32
#include <windows.h>
#endif
#ifdef __APPLE__
# include <GLUT/glut.h>
#else
# include <GL/glut.h>
#endif
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgGA/TrackballManipulator>
#include <osgDB/ReadFile>
osg::ref_ptr<osgViewer::Viewer> viewer;
osg::observer_ptr<osgViewer::GraphicsWindow> window;
void display(void)
{
// update and render the scene graph
if (viewer.valid()) viewer->frame();
// Swap Buffers
glutSwapBuffers();
glutPostRedisplay();
}
void reshape( int w, int h )
{
// update the window dimensions, in case the window has been resized.
if (window.valid())
{
window->resized(window->getTraits()->x, window->getTraits()->y, w, h);
window->getEventQueue()->windowResize(window->getTraits()->x, window->getTraits()->y, w, h );
}
}
void mousebutton( int button, int state, int x, int y )
{
if (window.valid())
{
if (state==0) window->getEventQueue()->mouseButtonPress( x, y, button+1 );
else window->getEventQueue()->mouseButtonRelease( x, y, button+1 );
}
}
void mousemove( int x, int y )
{
if (window.valid())
{
window->getEventQueue()->mouseMotion( x, y );
}
}
void keyboard( unsigned char key, int /*x*/, int /*y*/ )
{
switch( key )
{
case 27:
// clean up the viewer
if (viewer.valid()) viewer = 0;
glutDestroyWindow(glutGetWindow());
break;
default:
if (window.valid())
{
window->getEventQueue()->keyPress( (osgGA::GUIEventAdapter::KeySymbol) key );
window->getEventQueue()->keyRelease( (osgGA::GUIEventAdapter::KeySymbol) key );
}
break;
}
}
int main( int argc, char **argv )
{
glutInit(&argc, argv);
if (argc<2)
{
std::cout << argv[0] <<": requires filename argument." << std::endl;
return 1;
}
// load the scene.
osg::ref_ptr<osg::Node> loadedModel = osgDB::readRefNodeFile(argv[1]);
if (!loadedModel)
{
std::cout << argv[0] <<": No data loaded." << std::endl;
return 1;
}
glutInitDisplayMode( GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH | GLUT_ALPHA );
glutInitWindowPosition( 100, 100 );
glutInitWindowSize( 800, 600 );
glutCreateWindow( argv[0] );
glutDisplayFunc( display );
glutReshapeFunc( reshape );
glutMouseFunc( mousebutton );
glutMotionFunc( mousemove );
glutKeyboardFunc( keyboard );
// create the view of the scene.
viewer = new osgViewer::Viewer;
window = viewer->setUpViewerAsEmbeddedInWindow(100,100,800,600);
viewer->setSceneData(loadedModel.get());
viewer->setCameraManipulator(new osgGA::TrackballManipulator);
viewer->addEventHandler(new osgViewer::StatsHandler);
viewer->realize();
glutMainLoop();
return 0;
}
/*EOF*/