Introduced CMake option OSG_PROVIDE_READFILE option that defaults to ON, but when switched to OFF disables the building of the osgDB::read*File() methods,

forcing users to use osgDB::readRef*File() methods.  The later is preferable as it closes a potential threading bug when using paging databases in conjunction
with the osgDB::Registry Object Cache.  This threading bug occurs when one thread gets an object from the Cache via an osgDB::read*File() call where only
a pointer to the object is passed back, so taking a reference to the object is delayed till it gets reassigned to a ref_ptr<>, but at the same time another
thread calls a flush of the Object Cache deleting this object as it's referenceCount is now zero.  Using osgDB::readREf*File() makes sure the a ref_ptr<> is
passed back and the referenceCount never goes to zero.

To ensure the OSG builds when OSG_PROVIDE_READFILE is to OFF the many cases of osgDB::read*File() usage had to be replaced with a ref_ptr<> osgDB::readRef*File()
usage.  The avoid this change causing lots of other client code to be rewritten to handle the use of ref_ptr<> in place of C pointer I introduced a serious of
templte methods in various class to adapt ref_ptr<> to the underly C pointer to be passed to old OSG API's, example of this is found in include/osg/Group:

    bool addChild(Node* child); // old method which can only be used with a Node*

    tempalte<class T> bool addChild(const osg::ref_ptr<T>& child) { return addChild(child.get()); } // adapter template method

These changes together cover 149 modified files, so it's a large submission. This extent of changes are warrent to make use of the Object Cache
and multi-threaded loaded more robust.



git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/branches/OpenSceneGraph-3.4@15165 16af8721-9629-0410-8352-f15c8da7e697

include/osgWidget/Frame

@@ -175,6 +175,18 @@ class OSGWIDGET_EXPORT Frame: public Table
             Frame*       = 0
         );
 
+        template<class T>
+        static Frame* createSimpleFrameWithSingleTexture(
+            const std::string& name,
+            const osg::ref_ptr<T>& image,
+            point_type width,
+            point_type height,
+            unsigned int flags = 0,
+            Frame* exFrame = 0)
+        {
+            return Frame::createSimpleFrameWithSingleTexture(name, image.get(), width, height, flags, exFrame);
+        }
+
         static Frame* createSimpleFrameFromTheme(
             const std::string&,
             osg::Image*,
@@ -184,6 +196,18 @@ class OSGWIDGET_EXPORT Frame: public Table
             Frame*       = 0
         );
 
+        template<class T>
+        static Frame* createSimpleFrameFromTheme(
+            const std::string& name,
+            const osg::ref_ptr<T>& image,
+            point_type width,
+            point_type height,
+            unsigned int flags = 0,
+            Frame* exFrame = 0)
+        {
+            return Frame::createSimpleFrameFromTheme(name, image.get(), width, height, flags, exFrame);
+        }
+
         void createSimpleFrame(point_type cw, point_type ch, point_type w, point_type h)
         {
             createSimpleFrame(_name, cw, ch, w, h, 0, this);

include/osgWidget/Widget

@@ -129,6 +129,10 @@ public:
         void setTexCoordWrapVertical   ();
 
         bool setImage   (osg::Image*, bool = false, bool = false);
+
+        template<class T> bool setImage(const osg::ref_ptr<T>& image, bool f1 = false, bool f2 = false) { return setImage(image.get(), f1, f2); }
+
+
         bool setImage   (const std::string&, bool = false, bool = false);
         bool setTexture (osg::Texture*, bool = false, bool = false);