From e2f4e96416d38ab7b73df6e6b4477b758ed1e779 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 5 May 2009 11:05:17 +0000
Subject: [PATCH] Added checks to prevent crash when no imagery is applied

---
 src/osgVolume/FixedFunctionTechnique.cpp | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/osgVolume/FixedFunctionTechnique.cpp b/src/osgVolume/FixedFunctionTechnique.cpp
index d3885f340..404186263 100644
--- a/src/osgVolume/FixedFunctionTechnique.cpp
+++ b/src/osgVolume/FixedFunctionTechnique.cpp
@@ -98,9 +98,25 @@ osg::Node* createCube(const osg::Vec3& center, float size, unsigned int numSlice
 
 void FixedFunctionTechnique::init()
 {
-    osg::notify(osg::NOTICE)<<"FixedFunctionTechnique::init()"<<std::endl;
+    osg::notify(osg::INFO)<<"FixedFunctionTechnique::init()"<<std::endl;
 
-    if (!_volumeTile) return;
+    if (!_volumeTile)
+    {
+        osg::notify(osg::NOTICE)<<"FixedFunctionTechnique::init(), error no volume tile assigned."<<std::endl;
+        return;
+    }
+
+    if (_volumeTile->getLayer()==0)
+    {
+        osg::notify(osg::NOTICE)<<"FixedFunctionTechnique::init(), error no layer assigend to volume tile."<<std::endl;
+        return;
+    }
+
+    if (_volumeTile->getLayer()->getImage()==0)
+    {
+        osg::notify(osg::NOTICE)<<"FixedFunctionTechnique::init(), error no image assigned to layer."<<std::endl;
+        return;
+    }
 
     float alphaFuncValue = 0.1;