Improved handling of clean up of osg::Program/osg::Shader on closing of a graphis context.

include/osg/Program

@@ -132,7 +132,7 @@ class OSG_EXPORT Program : public osg::StateAttribute
 
                 void requestLink();
                 void linkProgram();
-                void validateProgram();
+                bool validateProgram();
                 bool needsLink() const {return _needsLink;}
                 bool isLinked() const {return _isLinked;}
                 bool getInfoLog( std::string& infoLog ) const;

include/osg/Shader

@@ -81,6 +81,11 @@ class OSG_EXPORT Shader : public osg::Object
         /** Get the Shader type as a descriptive string. */
         const char* getTypename() const;
 
+        /** release OpenGL objects in specified graphics context if State
+            object is passed, otherwise release OpenGL objects for all graphics context if
+            State object pointer NULL.*/
+        void releaseGLObjects(osg::State* state=0) const;
+
         /** Mark our PCSs as needing recompilation.
           * Also mark Programs that depend on us as needing relink */
         void dirtyShader();        

src/osg/Program.cpp

@@ -1999,9 +1999,19 @@ void Program::dirtyProgram()
 }
 
 
-void Program::releaseGLObjects(osg::State* /*state*/) const
+void Program::releaseGLObjects(osg::State* state) const
 {
-    // TODO
+    for( unsigned int i=0; i < _shaderList.size(); ++i )
+    {
+        if (_shaderList[i].valid()) _shaderList[i]->releaseGLObjects(state);
+    }
+
+    if (!state) _pcpList.setAllElementsTo(0);
+    else
+    {
+        unsigned int contextID = state->getContextID();
+        _pcpList[contextID] = 0;
+    }   
 }
 
 
@@ -2274,13 +2284,13 @@ void Program::PerContextProgram::linkProgram()
     osg::notify(osg::INFO) << std::endl;
 }
 
-void Program::PerContextProgram::validateProgram()
+bool Program::PerContextProgram::validateProgram()
 {
     GLint validated = GL_FALSE;
     _extensions->glValidateProgram( _glProgramHandle );
     _extensions->glGetProgramiv( _glProgramHandle, GL_VALIDATE_STATUS, &validated );
     if( validated == GL_TRUE)
-        return;
+        return true;
 
     osg::notify(osg::INFO)
         << "glValidateProgram FAILED \"" << _program->getName() << "\""
@@ -2293,6 +2303,8 @@ void Program::PerContextProgram::validateProgram()
         osg::notify(osg::INFO) << "infolog:\n" << infoLog << std::endl;
 
     osg::notify(osg::INFO) << std::endl;
+    
+    return false;
 }
 
 bool Program::PerContextProgram::getInfoLog( std::string& infoLog ) const

src/osg/Shader.cpp

@@ -201,6 +201,16 @@ const char* Shader::getTypename() const
 }
 
 
+void Shader::releaseGLObjects(osg::State* state) const
+{
+    if (!state) _pcsList.setAllElementsTo(0);
+    else
+    {
+        unsigned int contextID = state->getContextID();
+        _pcsList[contextID] = 0;
+    }
+}
+
 void Shader::compileShader( unsigned int contextID ) const
 {
     PerContextShader* pcs = getPCS( contextID );

src/osgUtil/SceneView.cpp

@@ -736,6 +736,9 @@ void SceneView::releaseAllGLObjects()
     if (!_camera) return;
    
     _camera->releaseGLObjects(_state.get());
+    
+    // we need to reset State as it keeps handles to Program objects.
+    if (_state.valid()) _state->reset();
 }