added start and end render methods

src/GlrRen.cc

@@ -164,6 +164,11 @@ int vlGlrRenderer::UpdateLights ()
 // Concrete gl render method.
 void vlGlrRenderer::Render(void)
 {
+  if (this->StartRenderMethod) 
+    {
+    (*this->StartRenderMethod)(this->StartRenderMethodArg);
+    }
+
   // standard render method 
   this->ClearLights();
   this->DoCameras();
@@ -177,6 +182,11 @@ void vlGlrRenderer::Render(void)
     {
     this->VolumeRenderer->Render((vlRenderer *)this);
     }
+
+  if (this->EndRenderMethod) 
+    {
+    (*this->EndRenderMethod)(this->EndRenderMethodArg);
+    }
 }
 
 // Description:

src/SbrRen.cc

@@ -147,6 +147,11 @@ void vlSbrRenderer::Render(void)
 {
   vlSbrRenderWindow *temp;
 
+  if (this->StartRenderMethod) 
+    {
+    (*this->StartRenderMethod)(this->StartRenderMethodArg);
+    }
+
   // update our Fd first
   temp = (vlSbrRenderWindow *)this->GetRenderWindow();
   this->Fd = temp->GetFd();
@@ -161,6 +166,11 @@ void vlSbrRenderer::Render(void)
     {
     this->VolumeRenderer->Render((vlRenderer *)this);
     }
+
+  if (this->EndRenderMethod) 
+    {
+    (*this->EndRenderMethod)(this->EndRenderMethodArg);
+    }
 }
 
 // Description: