From 6a73dfc193d9fadb64f46f0e52b91d8eb6d3adc4 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 20 Apr 2010 11:13:27 +0000
Subject: [PATCH] From Farshid Lashkari, "Anaglyphic stereo does not seem to
 work properly when performing pre-render stages. I believe the reason is that
 the pre-render stages are performed with the last applied color mask, which
 is cyan. I've fixed this by resetting the color mask before performing the
 pre-render stages."

---
 src/osgUtil/SceneView.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/osgUtil/SceneView.cpp b/src/osgUtil/SceneView.cpp
index ce977a3a4..39e133c8f 100644
--- a/src/osgUtil/SceneView.cpp
+++ b/src/osgUtil/SceneView.cpp
@@ -1112,6 +1112,20 @@ void SceneView::draw()
                     _renderStageRight->setDrawBuffer(_camera->getDrawBuffer());
                     _renderStageRight->setReadBuffer(_camera->getDrawBuffer());
                 }
+
+                // ensure that all color planes are active.
+                osg::ColorMask* cmask = static_cast<osg::ColorMask*>(_localStateSet->getAttribute(osg::StateAttribute::COLORMASK));
+                if (cmask)
+                {
+                    cmask->setMask(true,true,true,true);
+                }
+                else
+                {
+                    cmask = new osg::ColorMask(true,true,true,true);
+                    _localStateSet->setAttribute(cmask);
+                }
+                _renderStageLeft->setColorMask(cmask);
+                _renderStageRight->setColorMask(cmask);
                 
                 _localStateSet->setAttribute(getViewport());