Added osgFX::MultiTextureControl node for managing blending between

different texture layers.

include/osgFX/MultiTextureControl

@@ -0,0 +1,53 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2005 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 OSGFX_MULTITEXTURECONTROL
+#define OSGFX_MULTITEXTURECONTROL
+
+#include <osg/Group>
+
+#include <osgFX/Export>
+
+namespace osgFX
+{
+    /**
+      This node provides control over the which texture units are active and the
+      blending weighting between them.
+     */
+    class OSGFX_EXPORT MultiTextureControl: public osg::Group {
+    public:
+
+        MultiTextureControl();
+        MultiTextureControl(const MultiTextureControl& copy, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY);
+
+        META_Node(osgFX, MultiTextureControl);
+        
+        void setTextureWeight(unsigned int unit, float weight);
+
+        float getTextureWeight(unsigned int unit) const { return (unit<_textureWeightList.size()) ?  _textureWeightList[unit] : 0.0f; }
+        
+        unsigned int getNumTextureWeights() const { return _textureWeightList.size(); }
+        
+    protected:
+        virtual ~MultiTextureControl() {}
+        MultiTextureControl& operator = (const MultiTextureControl&) { return *this; }
+        
+        void updateStateSet();
+        
+        typedef std::vector<float> TextureWeightList;
+        TextureWeightList _textureWeightList;
+    };
+
+}
+
+#endif