From 62f5a4d3bc9c874e057e694cbe9144a2170cf6cf Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Mon, 18 May 2009 15:49:19 +0000
Subject: [PATCH] Merged changed from svn/trunk, improving the reliability of
 the clear of the stencil and depth buffer.

---
 src/osgUtil/RenderStage.cpp | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/src/osgUtil/RenderStage.cpp b/src/osgUtil/RenderStage.cpp
index 836454d21..95b0b6418 100644
--- a/src/osgUtil/RenderStage.cpp
+++ b/src/osgUtil/RenderStage.cpp
@@ -1202,17 +1202,12 @@ void RenderStage::drawImplementation(osg::RenderInfo& renderInfo,RenderLeaf*& pr
     // set up the back buffer.
     state.applyAttribute(_viewport.get());
 
-#define USE_SISSOR_TEST
-#ifdef USE_SISSOR_TEST
     glScissor( static_cast<int>(_viewport->x()),
                static_cast<int>(_viewport->y()),
                static_cast<int>(_viewport->width()),
                static_cast<int>(_viewport->height()) );
     //cout << "    clearing "<<this<< "  "<<_viewport->x()<<","<< _viewport->y()<<","<< _viewport->width()<<","<< _viewport->height()<<std::endl;
-    
-    glEnable( GL_SCISSOR_TEST );
-#endif
-
+    state.applyMode( GL_SCISSOR_TEST, true );
 
     // glEnable( GL_DEPTH_TEST );
 
@@ -1221,21 +1216,33 @@ void RenderStage::drawImplementation(osg::RenderInfo& renderInfo,RenderLeaf*& pr
     else glColorMask(GL_TRUE,GL_TRUE,GL_TRUE,GL_TRUE);
 
     if (_clearMask & GL_COLOR_BUFFER_BIT)
+    {
         glClearColor( _clearColor[0], _clearColor[1], _clearColor[2], _clearColor[3]);
+    }
 
     if (_clearMask & GL_DEPTH_BUFFER_BIT)
+    {
         glClearDepth( _clearDepth);
+        glDepthMask ( GL_TRUE );
+        state.haveAppliedAttribute( osg::StateAttribute::DEPTH );
+    }
 
     if (_clearMask & GL_STENCIL_BUFFER_BIT)
+    {
         glClearStencil( _clearStencil);
+        glStencilMask ( GL_TRUE );
+        state.haveAppliedAttribute( osg::StateAttribute::STENCIL );
+    }
 
     if (_clearMask & GL_ACCUM_BUFFER_BIT)
+    {
         glClearAccum( _clearAccum[0], _clearAccum[1], _clearAccum[2], _clearAccum[3]);
+    }
 
 
     glClear( _clearMask );
     
-#ifdef USE_SISSOR_TEST
+#ifdef USE_SCISSOR_TEST
     glDisable( GL_SCISSOR_TEST );
 #endif