From Mihair Radu, "Most of the additions are small utility methods:

- set the resolution of the shadow map; it calls dirty() to
re-initialize at next update
- keep a list of Shader objects to use instead of the default ones, if
the list is empty, the default shaders are used
- explicitly create the Uniform variables, so that subsequent additions
that require more Uniforms can put them in a central place
- set a Light or LightSource to use explicitly for shadow casting,
allows multiple lights in the scene, with one casting shadows

There are two additions that do not ( yet ) function correctly, but in
the present usage they do not interfere with the regular usage of the
techique:
- support for using spotlights, it's using Light.spotCutoff to determine
if it's a spot-light and not point-light,
   there is an error in the setup of either the shadow camera or the
texgen, most likely due to the direction of the spotlight, since the
position is being used just like in point or directional lights.
- creation of a debugHUD
   the hud is created properly, ( the example included shows it ), but
it displays only white, there has been some discussion of displaying the
shadow map, but I could not find it, the addition of a simple fragment
shader with the appropriate color transform should get this going."

include/osgShadow/ShadowMap

@@ -16,6 +16,8 @@
 
 #include <osg/Camera>
 #include <osg/Material>
+#include <osg/MatrixTransform>
+#include <osg/LightSource>
 
 #include <osgShadow/ShadowTechnique>
 
@@ -35,14 +37,34 @@ class OSGSHADOW_EXPORT ShadowMap : public ShadowTechnique
         void setTextureUnit(unsigned int unit);
 
         /** Get the texture unit that the shadow texture will be applied on.*/
-        unsigned int getTextureUnit() const { return _textureUnit; }
+        unsigned int getTextureUnit() const { return _shadowTextureUnit; }
 
         /** Set the values for the ambient bias the shader will use.*/
         void setAmbientBias(const osg::Vec2& ambientBias );
 
         /** Get the values that are used for the ambient bias in the shader.*/
         const osg::Vec2& getAmbientBias() const { return _ambientBias; }
-     
+
+        /** set the size in pixels x / y for the shadow texture.*/
+        void setTextureSize(const osg::Vec2s& textureSize);
+
+        /** Get the values that are used for the ambient bias in the shader.*/
+        const osg::Vec2s& getTextureSize() const { return _textureSize; }
+
+        /** Set the Light that will cast shadows */
+        void setLight(osg::Light* light);
+        void setLight(osg::LightSource* ls);
+
+        typedef std::vector< osg::ref_ptr<osg::Uniform> > UniformList;
+
+        typedef std::vector< osg::ref_ptr<osg::Shader> > ShaderList;
+
+        /** Add a shader to internal list, will be used instead of the default ones */
+        inline void addShader(osg::Shader* shader) { _shaderList.push_back(shader); }
+        
+        /** Reset internal shader list */
+        inline void clearShaderList() { _shaderList.clear(); }
+
         /** initialize the ShadowedScene and local cached data structures.*/
         virtual void init();
         
@@ -55,19 +77,35 @@ class OSGSHADOW_EXPORT ShadowMap : public ShadowTechnique
         /** Clean scene graph from any shadow technique specific nodes, state and drawables.*/
         virtual void cleanSceneGraph();
         
+        // debug methods
 
-    protected :
+        osg::ref_ptr<osg::Camera> makeDebugHUD();
 
-        virtual ~ShadowMap() {}
+    protected:
+        virtual ~ShadowMap(void) {};
+
+        /** Create the managed Uniforms */
+        void createUniforms();
+
+        void createShaders();
 
         osg::ref_ptr<osg::Camera>       _camera;
         osg::ref_ptr<osg::TexGen>       _texgen;
         osg::ref_ptr<osg::Texture2D>    _texture;
         osg::ref_ptr<osg::StateSet>     _stateset;
-        unsigned int                    _textureUnit;
+        osg::ref_ptr<osg::Program>      _program;
+        osg::ref_ptr<osg::Light>        _light;
+
+        osg::ref_ptr<osg::LightSource>  _ls;
+
+        UniformList                     _uniformList;
+        ShaderList                      _shaderList;
+        unsigned int                    _baseTextureUnit;
+        unsigned int                    _shadowTextureUnit;
         osg::Vec2                       _ambientBias;
-        
-};
+        osg::Vec2s                      _textureSize;
+
+    };
 
 }