From 41f7efbab6217642628d018e9601838e87de7059 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Mon, 14 May 2018 10:47:50 +0100
Subject: [PATCH] Imoroved backwards compatibility with 3.6

---
 include/osg/Callback    |  2 +-
 include/osg/Object      |  8 ++++++++
 include/osg/Uniform     |  2 ++
 include/osg/UniformBase |  3 +++
 src/osg/Callback.cpp    | 11 +++++++++++
 5 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/include/osg/Callback b/include/osg/Callback
index 07924b52f..e1250abee 100644
--- a/include/osg/Callback
+++ b/include/osg/Callback
@@ -286,7 +286,7 @@ public:
     virtual bool run(osg::Object* object, osg::Object* data);
 
     /** do customized update code.*/
-    virtual void operator () (UniformBase*, NodeVisitor*) {}
+    virtual void operator () (UniformBase* ub, NodeVisitor* nv);
 
     virtual void operator () (Uniform*, NodeVisitor*) {}
 
diff --git a/include/osg/Object b/include/osg/Object
index f15257e2b..a03ec1226 100644
--- a/include/osg/Object
+++ b/include/osg/Object
@@ -135,6 +135,14 @@ class OSG_EXPORT Object : public Referenced
           * Equivalent to dynamic_cast<Uniform*>(this).*/
         virtual Uniform* asUniform() { return 0; }
 
+        /** convert 'const this' into a const Uniform pointer if Object is a Uniform, otherwise return 0.
+          * Equivalent to dynamic_cast<const UniformBase*>(this).*/
+        virtual const UniformBase* asUniformBase() const { return 0; }
+
+        /** Convert 'this' into a Uniform pointer if Object is a Uniform, otherwise return 0.
+          * Equivalent to dynamic_cast<UniformBase*>(this).*/
+        virtual UniformBase* asUniformBase() { return 0; }
+
         /** convert 'const this' into a const Uniform pointer if Object is a Uniform, otherwise return 0.
           * Equivalent to dynamic_cast<const Uniform*>(this).*/
         virtual const Uniform* asUniform() const { return 0; }
diff --git a/include/osg/Uniform b/include/osg/Uniform
index b15fc7a47..1d3668c5f 100644
--- a/include/osg/Uniform
+++ b/include/osg/Uniform
@@ -627,6 +627,8 @@ class OSG_EXPORT Uniform : public UniformBase
 
         virtual void apply(const GLExtensions* ext, GLint location) const;
 
+        typedef osg::UniformCallback Callback;
+
     protected:
 
         virtual ~Uniform();
diff --git a/include/osg/UniformBase b/include/osg/UniformBase
index 1d778fdd4..62bf5e4eb 100644
--- a/include/osg/UniformBase
+++ b/include/osg/UniformBase
@@ -33,6 +33,9 @@ class OSG_EXPORT UniformBase : public Object
 
         META_Object(osg, UniformBase);
 
+        virtual const UniformBase* asUniformBase() const { return this; }
+        virtual UniformBase* asUniformBase() { return this; }
+
         /** Set the name of the glUniform, ensuring it is only set once.*/
         virtual void setName( const std::string& name );
 
diff --git a/src/osg/Callback.cpp b/src/osg/Callback.cpp
index 064da571a..d005c9329 100644
--- a/src/osg/Callback.cpp
+++ b/src/osg/Callback.cpp
@@ -15,6 +15,7 @@
 #include <osg/ScriptEngine>
 #include <osg/RenderInfo>
 #include <osg/Drawable>
+#include <osg/Uniform>
 
 using namespace osg;
 
@@ -162,3 +163,13 @@ bool DrawableCullCallback::cull(osg::NodeVisitor* nv, osg::Drawable* drawable, o
 {
     return cull(nv, drawable, renderInfo? renderInfo->getState():0);
 }
+
+
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+//
+//
+void UniformCallback::operator () (UniformBase* ub, NodeVisitor* nv)
+{
+    Uniform* uniform = ub->asUniform();
+    if (uniform) this->operator()(uniform, nv);
+}