From Marcin Hajder, "This submission contains Texture2DMultisample osg implementation.

Texture2DMultismaple as name suggests provides means to directly access subsamples of rendered FBO target. (GLSL 1.5 texelFetch call).

Recently I was working on deferred renderer with OSG, during that I noticed there is no support for multisampled textures (GL_ARB_texture_multisample extension). After consultations with Paul Martz and Wojtek Lewandowski I added Texture2DMultisample class and made few necessary changes around osg::FrameBufferObject, osg::Texture and osgUtil::RenderStage classes."

and from follow email:

"Fixed. According to ARB_texture_multisample extension specification multisample textures  don't need TexParameters since they can only be fetched with  texelFetch."

include/osg/Texture2DMultisample

@@ -0,0 +1,95 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2010 Robert Osfield 
+ *
+ * This library is open source and may be redistributed and/or modified under  
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ * OpenSceneGraph Public License for more details.
+ *
+ * Texture2DMultisample codes Copyright (C) 2010 Marcin Hajder
+ * Thanks to to my company http://www.ai.com.pl for allowing me free this work.
+*/
+
+#ifndef OSG_TEXTURE2DMS
+#define OSG_TEXTURE2DMS 1
+
+#include <osg/Texture>
+
+namespace osg {
+
+ /** Texture2DMultisample state class which encapsulates OpenGL 2D multisampled texture functionality. 
+ * Multisampled texture were introduced with OpenGL 3.1 and extension GL_ARB_texture_multisample.
+ * See http://www.opengl.org/registry/specs/ARB/texture_multisample.txt for more info.
+ */
+
+class OSG_EXPORT Texture2DMultisample : public Texture
+{
+    public :
+        
+        Texture2DMultisample();
+
+        Texture2DMultisample(GLsizei numSamples, GLboolean fixedsamplelocations);
+
+        /** Copy constructor using CopyOp to manage deep vs shallow copy. */
+        Texture2DMultisample(const Texture2DMultisample& text,const CopyOp& copyop=CopyOp::SHALLOW_COPY);
+        
+        META_StateAttribute(osg, Texture2DMultisample,TEXTURE);
+
+        /** Return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs. */
+        virtual int compare(const StateAttribute& rhs) const;
+
+        virtual GLenum getTextureTarget() const 
+        { 
+          return GL_TEXTURE_2D_MULTISAMPLE; 
+        }
+
+        /** Sets the texture width and height. If width or height are zero,
+          * calculate the respective value from the source image size. */
+        inline void setTextureSize(int width, int height) const
+        {
+            _textureWidth = width;
+            _textureHeight = height;
+        }
+
+        inline void setNumSamples( int samples ) { _numSamples = samples; }
+
+        // unnecessary for Texture2DMultisample
+        virtual void setImage(unsigned int face, Image* image){}
+        virtual Image* getImage(unsigned int face){return NULL;}
+        virtual const Image* getImage(unsigned int face) const{return NULL;}
+        virtual unsigned int getNumImages() const{return 0;}
+        virtual void allocateMipmap(State& state) const {}
+
+        void setTextureWidth(int width) { _textureWidth=width; }
+        void setTextureHeight(int height) { _textureHeight=height; }
+
+        virtual int getTextureWidth() const { return _textureWidth; }
+        virtual int getTextureHeight() const { return _textureHeight; }
+        virtual int getTextureDepth() const { return 1; }
+
+        /** Bind the texture object. If the texture object hasn't already been
+          * compiled, create the texture mipmap levels. */
+        virtual void apply(State& state) const;
+
+    protected :
+
+        virtual ~Texture2DMultisample();
+
+        virtual void computeInternalFormat() const;
+
+        /** Subloaded images can have different texture and image sizes. */
+        mutable GLsizei _textureWidth, _textureHeight;
+
+        mutable GLsizei _numSamples;
+
+        mutable GLboolean _fixedsamplelocations;
+
+};
+
+}
+
+#endif