dded osg::ClipNode class for managing OpenGL clipping planes, and osgclip demo.

src/Demos/osgclip/Makefile

@@ -0,0 +1,15 @@
+TOPDIR = ../../..
+include $(TOPDIR)/Make/makedefs 
+
+CXXFILES =\
+	osgclip.cpp\
+
+LIBS     += $(OSG_LIBS) $(GLUT_LIB) $(GL_LIBS) $(X_LIBS) $(OTHER_LIBS) 
+
+INSTFILES = \
+	$(CXXFILES)\
+	Makefile.inst=Makefile
+
+EXEC = osgclip
+
+include $(TOPDIR)/Make/makerules 

src/Demos/osgclip/Makefile.inst

@@ -0,0 +1,11 @@
+TOPDIR = ../..
+include $(TOPDIR)/Make/makedefs
+
+CXXFILES =\
+	osgclip.cpp\
+
+LIBS     += $(OSG_LIBS) $(GLUT_LIB) $(GL_LIBS) $(X_LIBS) $(OTHER_LIBS) 
+
+EXEC = osgclip
+
+include $(TOPDIR)/Make/makerules

src/Demos/osgclip/osgclip.cpp

@@ -0,0 +1,189 @@
+#include <osg/Transform>
+#include <osg/ClipNode>
+#include <osg/Billboard>
+#include <osg/Geode>
+#include <osg/Group>
+#include <osg/Notify>
+#include <osg/Material>
+#include <osg/PolygonOffset>
+#include <osg/PolygonMode>
+#include <osg/LineStipple>
+
+#include <osgDB/Registry>
+#include <osgDB/ReadFile>
+
+#include <osgUtil/TrackballManipulator>
+#include <osgUtil/FlightManipulator>
+#include <osgUtil/DriveManipulator>
+#include <osgUtil/TransformCallback>
+
+#include <osgGLUT/glut>
+#include <osgGLUT/Viewer>
+
+#include <osgUtil/Optimizer>
+
+void write_usage(std::ostream& out,const std::string& name)
+{
+    out << std::endl;
+    out <<"usage:"<< std::endl;
+    out <<"    "<<name<<" [options] infile1 [infile2 ...]"<< std::endl;
+    out << std::endl;
+    out <<"options:"<< std::endl;
+    out <<"    -l libraryName      - load plugin of name libraryName"<< std::endl;
+    out <<"                          i.e. -l osgdb_pfb"<< std::endl;
+    out <<"                          Useful for loading reader/writers which can load"<< std::endl;
+    out <<"                          other file formats in addition to its extension."<< std::endl;
+    out <<"    -e extensionName    - load reader/wrter plugin for file extension"<< std::endl;
+    out <<"                          i.e. -e pfb"<< std::endl;
+    out <<"                          Useful short hand for specifying full library name as"<< std::endl;
+    out <<"                          done with -l above, as it automatically expands to"<< std::endl;
+    out <<"                          the full library name appropriate for each platform."<< std::endl;
+    out <<std::endl;
+    out <<"    -stereo             - switch on stereo rendering, using the default of,"<< std::endl;
+    out <<"                          ANAGLYPHIC or the value set in the OSG_STEREO_MODE "<< std::endl;
+    out <<"                          environmental variable. See doc/stereo.html for "<< std::endl;
+    out <<"                          further details on setting up accurate stereo "<< std::endl;
+    out <<"                          for your system. "<< std::endl;
+    out <<"    -stereo ANAGLYPHIC  - switch on anaglyphic(red/cyan) stereo rendering."<< std::endl;
+    out <<"    -stereo QUAD_BUFFER - switch on quad buffered stereo rendering."<< std::endl;
+    out <<std::endl;
+    out <<"    -stencil            - use a visual with stencil buffer enabled, this "<< std::endl;
+    out <<"                          also allows the depth complexity statistics mode"<< std::endl;
+    out <<"                          to be used (press 'p' three times to cycle to it)."<< std::endl;
+    out << std::endl;
+}
+
+
+osg::Node* decorate_with_clip_node(osg::Node* subgraph)
+{
+    osg::Group* rootnode = osgNew osg::Group;
+    
+
+    // create wireframe view of the model so the user can see
+    // what parts are being culled away.
+    osg::StateSet* stateset = new osg::StateSet;
+    osg::Material* material = new osg::Material;
+    osg::PolygonMode* polymode = new osg::PolygonMode;
+    polymode->setMode(osg::PolygonMode::FRONT_AND_BACK,osg::PolygonMode::LINE);
+    stateset->setAttributeAndModes(polymode,osg::StateAttribute::OVERRIDE_ON);
+    
+    osg::Group* wireframe_subgraph = osgNew osg::Group;
+    wireframe_subgraph->setStateSet(stateset);
+    wireframe_subgraph->addChild(subgraph);
+    rootnode->addChild(wireframe_subgraph);
+
+/*
+    // simple approach to adding a clipnode above a subrgaph.
+
+    // create clipped part.
+    osg::ClipNode* clipped_subgraph = osgNew osg::ClipNode;
+
+    osg::BoundingSphere bs = subgraph->getBound();
+    bs.radius()*= 0.4f;
+
+    osg::BoundingBox bb;
+    bb.expandBy(bs);
+
+
+    clipped_subgraph->createClipBox(bb);
+    clipped_subgraph->addChild(subgraph);
+    rootnode->addChild(clipped_subgraph);
+*/
+
+
+    // more complex approach to managing ClipNode, allowing
+    // ClipNode node to be transformed independantly from the subgraph
+    // that it is clipping.
+    
+    osg::Transform* transform= osgNew osg::Transform;
+
+    osg::NodeCallback* nc = new osgUtil::TransformCallback(subgraph->getBound().center(),osg::Vec3(0.0f,0.0f,1.0f),osg::inDegrees(45.0f));
+    transform->setAppCallback(nc);
+
+    osg::ClipNode* clipnode = osgNew osg::ClipNode;
+    osg::BoundingSphere bs = subgraph->getBound();
+    bs.radius()*= 0.4f;
+
+    osg::BoundingBox bb;
+    bb.expandBy(bs);
+
+    clipnode->createClipBox(bb);
+    clipnode->setCullingActive(false);
+
+    transform->addChild(clipnode);
+    rootnode->addChild(transform);
+
+
+    // create clipped part.
+    osg::Group* clipped_subgraph = osgNew osg::Group;
+
+    clipped_subgraph->setStateSet(clipnode->getStateSet());
+    clipped_subgraph->addChild(subgraph);
+    rootnode->addChild(clipped_subgraph);
+
+    return rootnode;
+}
+
+
+int main( int argc, char **argv )
+{
+
+    // initialize the GLUT
+    glutInit( &argc, argv );
+
+    if (argc<2)
+    {
+        write_usage(osg::notify(osg::NOTICE),argv[0]);
+        return 0;
+    }
+    
+    // create the commandline args.
+    std::vector<std::string> commandLine;
+    for(int i=1;i<argc;++i) commandLine.push_back(argv[i]);
+    
+
+    // initialize the viewer.
+    osgGLUT::Viewer viewer;
+    viewer.setWindowTitle(argv[0]);
+    
+    // configure the viewer from the commandline arguments, and eat any
+    // parameters that have been matched.
+    viewer.readCommandLine(commandLine);
+    
+    // configure the plugin registry from the commandline arguments, and 
+    // eat any parameters that have been matched.
+    osgDB::readCommandLine(commandLine);
+
+    // load the nodes from the commandline arguments.
+    osg::Node* loadedModel = osgDB::readNodeFiles(commandLine);
+    if (!loadedModel)
+    {
+        write_usage(osg::notify(osg::NOTICE),argv[0]);
+        return 1;
+    }
+  
+    // decorate the scenegraph with a clip node.
+    osg::Node* rootnode = decorate_with_clip_node(loadedModel);
+
+  
+    
+    // run optimization over the scene graph
+    osgUtil::Optimizer optimzer;
+    optimzer.optimize(rootnode);
+     
+    // add a viewport to the viewer and attach the scene graph.
+    viewer.addViewport( rootnode );
+    
+    // register trackball, flight and drive.
+    viewer.registerCameraManipulator(new osgUtil::TrackballManipulator);
+    viewer.registerCameraManipulator(new osgUtil::FlightManipulator);
+    viewer.registerCameraManipulator(new osgUtil::DriveManipulator);
+
+    // open the viewer window.
+    viewer.open();
+    
+    // fire up the event loop.
+    viewer.run();
+
+    return 0;
+}