From Ruben, addition of osg::PointSprite and osgpointsprite example.

include/osg/PointSprite

@@ -0,0 +1,55 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 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.
+ */
+
+#ifndef OSG_POINT_SPRITE
+#define OSG_POINT_SPRITE 1
+
+#include <osg/GL>
+#include <osg/StateAttribute>
+
+#ifndef GL_ARB_point_sprite
+#define GL_POINT_SPRITE_ARB               0x8861
+#define GL_COORD_REPLACE_ARB              0x8862
+#endif
+
+namespace osg {
+
+/** PointSprite base class which encapsulates enabling of point sprites .*/
+class SG_EXPORT PointSprite : public osg::StateAttribute {
+public:
+
+	PointSprite() {}
+
+	/** Copy constructor using CopyOp to manage deep vs shallow copy.*/
+	PointSprite(const PointSprite& texenv,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY):        
+	    StateAttribute(texenv,copyop) {}
+
+
+	META_StateAttribute(osg, PointSprite, GL_POINT_SPRITE_ARB);
+
+	/** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.*/
+	virtual int compare(const StateAttribute& sa) const;
+
+	virtual void getAssociatedModes(std::vector<GLMode>& modes) const;
+
+	virtual bool isTextureAttribute() const { return true; }
+
+	virtual void apply(osg::State& state) const;
+
+protected:
+	virtual ~PointSprite( void ) {}
+};
+
+}
+
+#endif