From f230f5a132b85f3a75e1f796bdab0acd36da3f58 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Mon, 5 Jan 2004 13:40:36 +0000
Subject: [PATCH] Added support into osgProducer::Viewer for flushing and
 compiling GL objects via a Producer post swap callback.

---
 include/osgUtil/SceneView  |  5 +++++
 src/osgProducer/Viewer.cpp | 45 +++++++++++++++++++++++++++++++++++++-
 src/osgUtil/SceneView.cpp  | 31 ++++++++++++++++----------
 3 files changed, 68 insertions(+), 13 deletions(-)

diff --git a/include/osgUtil/SceneView b/include/osgUtil/SceneView
index 762c92d4a..a3a97d677 100644
--- a/include/osgUtil/SceneView
+++ b/include/osgUtil/SceneView
@@ -430,6 +430,9 @@ class OSGUTIL_EXPORT SceneView : public osg::Referenced
         /** Do draw traversal of draw bins generated by cull traversal.*/
         virtual void draw();
         
+        /** Flush all the OpenGL objects, such as texture objects, display lists etc.*/
+        virtual void flushDeletedGLObjects(double& availableTime);
+        
     protected:
 
         virtual ~SceneView();
@@ -493,6 +496,8 @@ class OSGUTIL_EXPORT SceneView : public osg::Referenced
         
         GLenum                                      _drawBufferValue;
         
+        bool                                        _requiresFlush;
+        
 };
 
 }
diff --git a/src/osgProducer/Viewer.cpp b/src/osgProducer/Viewer.cpp
index bbf5165f7..2b7184645 100644
--- a/src/osgProducer/Viewer.cpp
+++ b/src/osgProducer/Viewer.cpp
@@ -371,9 +371,15 @@ public:
             
             sh.drawImplementation(camera);
 
-            double availableTime = 0.0025; //  5 ms
+#if 0
+            double availableTime = 0.0025; //  2.5 ms
 
+            // flush deleted GL objects.
+            sh.getSceneView()->flushDeletedGLObjects(availableTime);
+
+            // compile any GL objects that are required.
             _databasePager->compileRenderingObjects(*(sh.getSceneView()->getState()),availableTime);
+#endif
 
             _databasePager->signalEndFrame();
 
@@ -382,6 +388,33 @@ public:
        osg::ref_ptr<osgDB::DatabasePager> _databasePager;
 };
 
+class PostSwapCompileCallback : public Producer::Camera::Callback
+{
+public:
+
+        PostSwapCompileCallback(osgUtil::SceneView* sceneView,osgDB::DatabasePager* databasePager):
+            _sceneView(sceneView),
+            _databasePager(databasePager)
+        {}
+
+       virtual void operator()(const Producer::Camera&)
+       {
+            
+            double availableTime = 0.0025; //  5 ms
+
+            // compile any GL objects that are required.
+            _databasePager->compileRenderingObjects(*(_sceneView->getState()),availableTime);
+
+            // flush deleted GL objects.
+            _sceneView->flushDeletedGLObjects(availableTime);
+
+
+       }
+       
+       osg::ref_ptr<osgUtil::SceneView>     _sceneView;
+       osg::ref_ptr<osgDB::DatabasePager>   _databasePager;
+};
+
 bool Viewer::realize()
 {
     if (_realized) return _realized;
@@ -408,10 +441,20 @@ bool Viewer::realize()
             // set up a draw callback to pre compile any rendering object of database has loaded, 
             // but not yet merged with the main scene graph.
             (*p)->setDrawCallback(new DatabasePagerCompileCallback(_databasePager.get()));
+
             
             // tell the database pager which graphic context the compile of rendering objexts is needed.
             _databasePager->setCompileRenderingObjectsForContexID((*p)->getSceneView()->getState()->getContextID(),true);
         }
+
+    
+        // set up a post swap callback to flush deleted GL objects and compile new GL objects            
+        for(unsigned int cameraNum=0;cameraNum<getNumberOfCameras();++cameraNum)
+        {
+            Producer::Camera* camera=getCamera(cameraNum);
+            camera->addPostSwapCallback(new PostSwapCompileCallback(_shvec[cameraNum]->getSceneView(),_databasePager.get()));
+        }
+
     }
     
     // force a sync before we intialize the keyswitch manipulator to home
diff --git a/src/osgUtil/SceneView.cpp b/src/osgUtil/SceneView.cpp
index 3a9d24df0..8fa60eddd 100644
--- a/src/osgUtil/SceneView.cpp
+++ b/src/osgUtil/SceneView.cpp
@@ -59,6 +59,7 @@ SceneView::SceneView(DisplaySettings* ds)
     
     _drawBufferValue = GL_BACK;
 
+    _requiresFlush = true;
 }
 
 
@@ -612,6 +613,17 @@ void SceneView::cullStage(const osg::Matrixd& projection,const osg::Matrixd& mod
 }
 
 
+void SceneView::flushDeletedGLObjects(double& availableTime)
+{
+    _requiresFlush = false;
+
+    double currentTime = _state->getFrameStamp()?_state->getFrameStamp()->getReferenceTime():0.0;
+    osg::Texture::flushTextureObjects(_state->getContextID(),currentTime,availableTime);
+    osg::Drawable::flushDeletedDisplayLists(_state->getContextID(),currentTime,availableTime);
+    osg::Drawable::flushDeletedVertexBufferObjects(_state->getContextID(),currentTime,availableTime);
+    osg::VertexProgram::flushDeletedVertexProgramObjects(_state->getContextID(),currentTime,availableTime);
+    osg::FragmentProgram::flushDeletedFragmentProgramObjects(_state->getContextID(),currentTime,availableTime);
+}
 
 void SceneView::draw()
 {
@@ -621,19 +633,14 @@ void SceneView::draw()
     // context for when the object were originally created.  Here we know what
     // context we are in so can flush the appropriate caches.
     
-    //static osg::Timer timer;
-    //osg::Timer_t tstart = timer.tick();
-    
-    double currentTime = _state->getFrameStamp()?_state->getFrameStamp()->getReferenceTime():0.0;
-    double availableTime = 0.005; // 5 ms.
-    osg::Drawable::flushDeletedDisplayLists(_state->getContextID(),currentTime,availableTime);
-    osg::Drawable::flushDeletedVertexBufferObjects(_state->getContextID(),currentTime,availableTime);
-    osg::VertexProgram::flushDeletedVertexProgramObjects(_state->getContextID(),currentTime,availableTime);
-    osg::FragmentProgram::flushDeletedFragmentProgramObjects(_state->getContextID(),currentTime,availableTime);
-    osg::Texture::flushTextureObjects(_state->getContextID(),currentTime,availableTime);
+    if (_requiresFlush)
+    {
+        double availableTime = 0.005;
+        flushDeletedGLObjects(availableTime);
+    }
 
-    //osg::Timer_t tend = timer.tick();
-    //std::cout<<"time to flush rendering objects"<<timer.delta_m(tstart,tend)<<std::endl;
+    // assume the the draw which is about to happen could generate GL objects that need flushing in the next frame.
+    _requiresFlush = true;
 
     _state->setInitialViewMatrix(new osg::RefMatrix(_viewMatrix));