From eabe2faf7e393a6f150ca4b76d83b05482def5e7 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 28 Aug 2007 14:02:16 +0000
Subject: [PATCH] Added multi-threaded test path

---
 examples/osgtext/osgtext.cpp | 182 ++++++++++++++++++++++++++++++++++-
 1 file changed, 177 insertions(+), 5 deletions(-)

diff --git a/examples/osgtext/osgtext.cpp b/examples/osgtext/osgtext.cpp
index 63ad5be11..99ab1f333 100644
--- a/examples/osgtext/osgtext.cpp
+++ b/examples/osgtext/osgtext.cpp
@@ -23,11 +23,14 @@
 #include <osgDB/Registry>
 
 #include <osgViewer/Viewer>
+#include <osgViewer/ViewerEventHandlers>
 
 #include <osg/Geode>
 #include <osg/Camera>
 #include <osg/ShapeDrawable>
 #include <osg/Sequence>
+#include <osg/PolygonMode>
+#include <osg/io_utils>
 
 #include <osgText/Font>
 #include <osgText/Text>
@@ -474,13 +477,173 @@ osg::Group* create3DText(const osg::Vec3& center,float radius)
     return rootNode;    
 }
 
-int main(int , char **)
+class UpdateTextOperation : public osg::Operation
 {
-    // construct the viewer.
-    osgViewer::Viewer viewer;
+public:
 
-    // prepare scene.
+    UpdateTextOperation(osg::Group* group):        
+        Operation("UpdateTextOperation", true),
+        _group(group),
+        _maxNumChildren(20),
+        _maxNumTextPerGeode(100)
     {
+    }
+
+    virtual void operator () (osg::Object* callingObject)
+    {
+        // decided which method to call according to whole has called me.
+        osgViewer::Viewer* viewer = dynamic_cast<osgViewer::Viewer*>(callingObject);
+
+        if (viewer) update();
+        else load();
+    }
+    
+    void update()
+    {
+        // osg::notify(osg::NOTICE)<<"*** Doing update"<<std::endl;
+        
+        OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
+        
+        if (_mergeSubgraph.valid())
+        {
+            _group->addChild(_mergeSubgraph.get());
+
+            _mergeSubgraph = 0;
+
+            if (_group->getNumChildren()>_maxNumChildren)
+            {
+                osg::Geode* geode = dynamic_cast<osg::Geode*>(_group->getChild(0));
+                if (geode)
+                {
+                    _availableSubgraph.push_back(geode);
+                    geode->removeDrawables(0,geode->getNumDrawables());
+                }
+                _group->removeChild(0,1);
+            }
+            
+            _waitOnMergeBlock.release();
+        }        
+    }
+    
+    void load()
+    {
+    
+        // osg::notify(osg::NOTICE)<<"Doing load"<<std::endl;
+
+        osg::ref_ptr<osg::Geode> geode;
+        {
+            OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
+            if (!_availableSubgraph.empty())
+            {
+                geode = _availableSubgraph.front();
+                _availableSubgraph.pop_front();
+            }
+        }
+        
+        if (!geode) geode = new osg::Geode;
+
+        for(unsigned int i=0; i<_maxNumTextPerGeode; ++i)
+        {
+            osg::Vec3 position(float(rand()) / float(RAND_MAX), float(rand()) / float(RAND_MAX), float(i)/float(_maxNumTextPerGeode));
+
+            std::string str;
+            unsigned int _numCharacters = 5;
+            for(unsigned int ni=0; ni<_numCharacters;++ni)
+            {
+                str.push_back(char(32.0 + (float(rand())/float(RAND_MAX))*128.0f));
+            }
+                        
+            osgText::Text* text = new osgText::Text;
+            text->setDataVariance(osg::Object::DYNAMIC);
+            text->setPosition(position);
+            text->setFont("times.ttf");
+            text->setText(str);
+            text->setCharacterSize(0.025f);
+            text->setAxisAlignment(osgText::Text::SCREEN);
+            
+            geode->addDrawable(text);
+        }
+
+
+        {        
+            OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
+            _mergeSubgraph = geode;
+        }
+        
+        // osg::notify(osg::NOTICE)<<"Waiting on merge"<<std::endl;
+
+        _waitOnMergeBlock.block();
+
+    }
+    
+    virtual void release()
+    {
+        _waitOnMergeBlock.release();
+    }
+
+    typedef std::list< osg::ref_ptr<osg::Geode> > AvailableList;
+
+    unsigned int                _maxNumChildren;
+    unsigned int                _maxNumTextPerGeode;
+    
+    OpenThreads::Mutex          _mutex;
+    osg::ref_ptr<osg::Group>    _group;
+    osg::ref_ptr<osg::Geode>    _mergeSubgraph;
+    AvailableList               _availableSubgraph;
+    OpenThreads::Block          _waitOnMergeBlock;
+    
+    unsigned int                _counter;
+
+};
+
+
+int main(int argc, char** argv)
+{
+    osg::ArgumentParser arguments(&argc, argv);
+
+    // construct the viewer.
+    osgViewer::Viewer viewer(arguments);
+
+    osg::ref_ptr<osg::OperationThread> operationThread;
+    osg::ref_ptr<UpdateTextOperation> updateOperation;
+
+    if (arguments.read("--mt"))
+    {
+        // construct a multi-threaded text updating test.
+        
+        // create a group to add everything into.
+        osg::Group* mainGroup = new osg::Group;
+
+        osg::Group* textGroup = new osg::Group;
+        mainGroup->addChild(textGroup);
+
+        // create the background thread
+        operationThread = new osg::OperationThread;
+        
+        // create the operation that will run in the background and
+        // sync once per frame with the main viewer loop.
+        updateOperation = new UpdateTextOperation(textGroup);
+        
+        // add the operation to the operation thread and start it.
+        operationThread->add(updateOperation.get());
+        operationThread->startThread();
+        
+        // add the operation to the viewer to sync once per frame.
+        viewer.addUpdateOperation(updateOperation.get());
+
+
+        // add a unit cube for the text to appear within.
+        osg::Geode* geode = new osg::Geode;
+        geode->getOrCreateStateSet()->setAttribute(new osg::PolygonMode(osg::PolygonMode::FRONT_AND_BACK,osg::PolygonMode::LINE));
+        geode->addDrawable(new osg::ShapeDrawable(new osg::Box(osg::Vec3(0.5f,0.5f,0.5f),1.0)));
+
+        mainGroup->addChild(geode);
+        
+        viewer.setSceneData(mainGroup);        
+    }
+    else
+    {
+        // prepare scene.
         osg::Vec3 center(0.0f,0.0f,0.0f);
         float radius = 1.0f;
         
@@ -506,8 +669,17 @@ int main(int , char **)
         viewer.setSceneData(group);
     }
 
+#if 0
     osgDB::writeNodeFile(*viewer.getSceneData(),"text.osg");
+#endif
 
-    return viewer.run();
+    viewer.addEventHandler(new osgViewer::StatsHandler());
+
+    viewer.run();
+    
+    if (operationThread.valid())
+    {
+        operationThread->cancel();
+    }
 }