From 90afef26bb92e8493ac2f2cd8b870b83231f27a9 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Thu, 21 Jul 2011 09:19:45 +0000
Subject: [PATCH] Merged from svn/trunk, workaround to culling issues
 assocaited with text that is set to scale relative to screen coords or is
 rotated to the screen.

---
 src/osgText/TextBase.cpp | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/osgText/TextBase.cpp b/src/osgText/TextBase.cpp
index 8b12808e9..090752d39 100644
--- a/src/osgText/TextBase.cpp
+++ b/src/osgText/TextBase.cpp
@@ -287,11 +287,17 @@ osg::BoundingBox TextBase::computeBound() const
 
         if (!bbox.valid())
         {
-            // provide a fallback in cases where no bounding box has been been setup so far
-            if (_characterSizeMode!=OBJECT_COORDS || _autoRotateToScreen)
+            // Provide a fallback in cases where no bounding box has been been setup so far.
+            // Note, assume a scaling of 1.0 for _characterSizeMode!=OBJECT_COORDS as the
+            // for screen space coordinates size modes we don't know what scale will be used until
+            // the text is actually rendered, but we haven't to assume something otherwise the
+            // text label will be culled by view or small feature culling on first frame.
+            if (_autoRotateToScreen)
             {
-                // default to a zero size.
-                bbox.set(_position, _position);
+                // use bounding sphere encompassing the maximum size of the text centered on the _position
+                double radius = _textBB.radius();
+                osg::Vec3 diagonal(radius, radius, radius);
+                bbox.set(_position-diagonal, _position+diagonal);
             }
             else
             {