From baeb41a416c78f6d378c8f4a9e9a2df4e36b76c5 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Mon, 30 Oct 2006 12:19:41 +0000
Subject: [PATCH] From Michael Henheffer, "There's a problem with OverlayNodes
 where the texture will not display if continuous updating is set to false.

The problem was being caused by the camera update call never being made
if continuous updating was not set to true.  This fix adds a flag that
is set when dirtyOverlayTexture() is called and checked in the update
visitor section of the traversal to determine if the camera should be
updated.

I tested the fix by making some changes to the osgAnimate example
program so it has continuous updating off and calls dirtyOverlayTexture
for each frame.  The overlay texture now displays properly."
---
 include/osgSim/OverlayNode | 1 +
 src/osgSim/OverlayNode.cpp | 8 +++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/osgSim/OverlayNode b/include/osgSim/OverlayNode
index aabd47df5..80b66c9e2 100644
--- a/include/osgSim/OverlayNode
+++ b/include/osgSim/OverlayNode
@@ -117,6 +117,7 @@ class OSGSIM_EXPORT OverlayNode : public osg::Group
         osg::ref_ptr<osg::Texture2D>    _texture;
 
         bool                            _continuousUpdate;
+        bool                            _updateCamera;
         osg::Polytope                   _textureFrustum;
 };
 
diff --git a/src/osgSim/OverlayNode.cpp b/src/osgSim/OverlayNode.cpp
index 47a1a665e..9d3338ade 100644
--- a/src/osgSim/OverlayNode.cpp
+++ b/src/osgSim/OverlayNode.cpp
@@ -26,7 +26,8 @@ OverlayNode::OverlayNode():
     _texEnvMode(GL_DECAL),
     _textureUnit(1),
     _textureSizeHint(1024),
-    _continuousUpdate(false)
+    _continuousUpdate(false),
+    _updateCamera(false)
 {
     setNumChildrenRequiringUpdateTraversal(1);
     init();
@@ -100,9 +101,8 @@ void OverlayNode::traverse(osg::NodeVisitor& nv)
 
         Group::traverse(nv);
 
-        if (_continuousUpdate)
+        if (_continuousUpdate || _updateCamera)
         {
-
             // now compute the camera's view and projection matrix to point at the shadower (the camera's children)
             osg::BoundingSphere bs;
             for(unsigned int i=0; i<_camera->getNumChildren(); ++i)
@@ -176,6 +176,7 @@ void OverlayNode::traverse(osg::NodeVisitor& nv)
                 _textureFrustum.setToUnitFrustum(false,false);
                 _textureFrustum.transformProvidingInverse(MVP);
             }
+            _updateCamera = false;
         }
 
         return;
@@ -257,6 +258,7 @@ void OverlayNode::setOverlaySubgraph(osg::Node* node)
 void OverlayNode::dirtyOverlayTexture()
 {
     _textureObjectValidList.setAllElementsTo(0);
+    _updateCamera = true;
 }
 
 void OverlayNode::setOverlayClearColor(const osg::Vec4& color)