From bac4cfe3d56c947b17665986d22b55d740e3e011 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 2 Jun 2010 15:07:27 +0000
Subject: [PATCH] Added check for presence of extension.

---
 src/osg/FrameBufferObject.cpp | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/osg/FrameBufferObject.cpp b/src/osg/FrameBufferObject.cpp
index 158a99f69..9990ecb82 100644
--- a/src/osg/FrameBufferObject.cpp
+++ b/src/osg/FrameBufferObject.cpp
@@ -561,13 +561,23 @@ void FrameBufferAttachment::attach(State &state, GLenum target, GLenum attachmen
         break;
     case Pimpl::TEXTURE3D:
         if (_ximpl->zoffset == Camera::FACE_CONTROLLED_BY_GEOMETRY_SHADER)
-            ext->glFramebufferTexture(target, attachment_point, tobj->id(), _ximpl->level);
+        {
+            if (ext->glFramebufferTexture)
+            {
+                ext->glFramebufferTexture(target, attachment_point, tobj->id(), _ximpl->level);
+            }
+        }
         else
             ext->glFramebufferTexture3D(target, attachment_point, GL_TEXTURE_3D, tobj->id(), _ximpl->level, _ximpl->zoffset);
         break;
     case Pimpl::TEXTURE2DARRAY:
-        if (_ximpl->zoffset == Camera::FACE_CONTROLLED_BY_GEOMETRY_SHADER)
-            ext->glFramebufferTexture(target, attachment_point, tobj->id(), _ximpl->level);
+        if (_ximpl->cubeMapFace == Camera::FACE_CONTROLLED_BY_GEOMETRY_SHADER)
+        {
+            if (ext->glFramebufferTexture)
+            {
+                ext->glFramebufferTexture(target, attachment_point, tobj->id(), _ximpl->level);
+            }
+        }
         else
             ext->glFramebufferTextureLayer(target, attachment_point, tobj->id(), _ximpl->level, _ximpl->zoffset);
         break;
@@ -576,7 +586,12 @@ void FrameBufferAttachment::attach(State &state, GLenum target, GLenum attachmen
         break;
     case Pimpl::TEXTURECUBE:
         if (_ximpl->cubeMapFace == Camera::FACE_CONTROLLED_BY_GEOMETRY_SHADER)
-            ext->glFramebufferTexture(target, attachment_point, tobj->id(), _ximpl->level);
+        {
+            if (ext->glFramebufferTexture)
+            {
+                ext->glFramebufferTexture(target, attachment_point, tobj->id(), _ximpl->level);
+            }
+        }
         else
             ext->glFramebufferTexture2D(target, attachment_point, GL_TEXTURE_CUBE_MAP_POSITIVE_X + _ximpl->cubeMapFace, tobj->id(), _ximpl->level);
         break;