Added set/getUnrefImageOnApply() methods and associated flag and

code in Texture::apply() to set the _image to 0 on apply.  Note,
this will only work when you have a single graphics context, as
with multiple graphics contexts one can't delete the image after
the first apply, as there will be more than one texture object to
update.

include/osg/Texture

@@ -82,6 +82,7 @@ class SG_EXPORT Texture : public StateAttribute
             _handleList(),
             _modifiedTag(),
             _image(copyop(text._image.get())),
+            _unrefImageAfterApply(text._unrefImageAfterApply),
             _target(text._target),
             _wrap_s(text._wrap_s),
             _wrap_t(text._wrap_t),
@@ -120,6 +121,10 @@ class SG_EXPORT Texture : public StateAttribute
 
         /** Get the const texture image. */
         inline const Image* getImage() const { return _image.get(); }
+        
+        void setUnrefImageAfterApply(bool unrefImage) { _unrefImageAfterApply = unrefImage; }
+
+        bool getUnrefImageAfterApply() const { return _unrefImageAfterApply; }
 
         /** Copy pixels into a 2D texture image.As per glCopyTexImage2D.
           * Creates an OpenGL texture object from the current OpenGL background
@@ -273,7 +278,7 @@ class SG_EXPORT Texture : public StateAttribute
         {
             // pad out handle list if required.
             if (_modifiedTag.size()<=contextID)
-                _modifiedTag.resize(contextID,0);
+                _modifiedTag.resize(contextID+1,0);
 
             // get the modified tag for the current contextID.
             return _modifiedTag[contextID];
@@ -329,6 +334,8 @@ class SG_EXPORT Texture : public StateAttribute
         // which is const...
         mutable ref_ptr<Image> _image;
 
+        bool _unrefImageAfterApply;
+
         GLenum _target; // defaults to GL_TEXTURE_2D
 
         WrapMode _wrap_s;

src/osg/Texture.cpp

@@ -20,6 +20,7 @@ Texture::DeletedTextureObjectCache Texture::s_deletedTextureObjectCache;
 
 Texture::Texture():
     _target(GL_TEXTURE_2D),
+    _unrefImageAfterApply(true),
     _wrap_s(CLAMP),
     _wrap_t(CLAMP),
     _wrap_r(CLAMP),
@@ -223,6 +224,9 @@ void Texture::apply(State& state) const
         // unless a second bind is called?!!
         // perhaps it is the first glBind which is not required...
         glBindTexture( _target, handle );
+        
+        if (_unrefImageAfterApply)
+            _image = 0;
 
     }
 }