Added new osgscribe demo which demostrates how to create a wireframe

overlay of a model.

src/Demos/Makefile

@@ -1,7 +1,7 @@
 #!smake
 SHELL=/bin/sh
 
-DIRS = sgv osgconv osgcube osgreflect osgtexture osgimpostor osgviews hangglide 
+DIRS = sgv osgconv osgcube osgscribe osgreflect osgtexture osgimpostor osgviews hangglide 
 
 # comment out if you don't have the freetype and GLU1.3 library installed.
 DIRS += osgtext 

src/Demos/osgscribe/Makefile

@@ -0,0 +1,22 @@
+#!smake
+include $(OSGHOME)/Make/makedefs
+
+C++FILES = \
+	osgscribe.cpp
+
+TARGET = $(OSGHOME)/bin/osgscribe
+
+TARGET_BIN_FILES = osgscribe
+
+#note, standard library list. 
+LIBS = -losgGLUT -losgUtil -losgDB -losg $(GLUTLIB) $(GL_LIBS) $(X_LIBS)
+
+#under Darwin we have to use the framework stuff to get GLUT OpenGL etc.
+MACOSXLIBS = -losgGLUT -losgUtil -losgDB -losg -lm -ldl -lstdc++ -lobjc
+
+
+C++FLAGS += -I$(OSGHOME)/include
+LDFLAGS += -L$(OSGHOME)/lib
+
+include $(OSGHOME)/Make/makerules
+

src/Demos/osgscribe/osgscribe.cpp

@@ -0,0 +1,145 @@
+#include <osg/Transform>
+#include <osg/Billboard>
+#include <osg/Geode>
+#include <osg/Group>
+#include <osg/Notify>
+#include <osg/Material>
+#include <osg/PolygonOffset>
+#include <osg/PolygonMode>
+
+#include <osgDB/Registry>
+#include <osgDB/ReadFile>
+
+#include <osgUtil/TrackballManipulator>
+#include <osgUtil/FlightManipulator>
+#include <osgUtil/DriveManipulator>
+
+#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;
+}
+
+
+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;
+    
+    // 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;
+    }
+  
+    // to do scribe mode we create a top most group to contain the
+    // original model, and then a second group contains the same model
+    // but overrides various state attributes, so that the second instance
+    // is rendered as wireframe.
+    
+    osg::Group* rootnode = new osg::Group;
+
+    osg::Group* decorator = new osg::Group;
+    
+    rootnode->addChild(loadedModel);
+    
+    
+    rootnode->addChild(decorator);
+    
+    decorator->addChild(loadedModel);  
+
+    // set up the state so that the underlying color is not seen through
+    // and that the drawing mode is changed to wireframe, and a polygon offset
+    // is added to ensure that we see the wireframe itself, and turn off 
+    // so texturing too.
+    osg::StateSet* stateset = new osg::StateSet;
+    osg::Material* material = new osg::Material;
+    osg::PolygonOffset* polyoffset = new osg::PolygonOffset;
+    polyoffset->setFactor(-1.0f);
+    polyoffset->setUnits(-1.0f);
+    osg::PolygonMode* polymode = new osg::PolygonMode;
+    polymode->setMode(osg::PolygonMode::FRONT_AND_BACK,osg::PolygonMode::LINE);
+    stateset->setAttributeAndModes(material,osg::StateAttribute::OVERRIDE_ON);
+    stateset->setAttributeAndModes(polyoffset,osg::StateAttribute::OVERRIDE_ON);
+    stateset->setAttributeAndModes(polymode,osg::StateAttribute::OVERRIDE_ON);
+    stateset->setMode(GL_TEXTURE_2D,osg::StateAttribute::OVERRIDE_OFF);
+    decorator->setStateSet(stateset);
+  
+    
+    // run optimization over the scene graph
+    osgUtil::Optimizer optimzer;
+// turn off temporarily since the above single child decorator group gets 
+// removed as the optimizer assumes its redundent.  Will fix next. Robert.
+//    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;
+}