abstraction layer definition - Which pattern to use?

[nsriram]

Hi all,
I am not sure whether the this topic is relevant to this thread. Any ways I hope you guys will lead me to the right path.

I am working on a simple graphics appplication that has to run on different graphics engines( say GTK , FLTK, etc).
I want to make my application common and can be ported to any graphic engines.

So there comes the abstraction layer between the application and the graphics engine.

To put it simple from top to bottom
1. Application 2. Draw Factory 3. Object pool 4. Abstratcion and finally 4. Graphics engine.

How do i go about in designing this abstraction ( What kind of design pattern approach should i take) ? we can also call this abstraction as "Object Base Classes" in oo terminology .

[nsriram]

In case my question is not clear here is a brief explanation. A question on implementing Abstraction layer on OODesign.
How can I design my graphics application suit for different Graphics Engine ? meaning I should have a single application(C++ based) which can be ported to any graphics engine( FLTK , GTK as of now).
I know that there should be an abstraction layer in between the Apllication and Graphics engine but I am unable to get an idea on the method to design it.

Any idea or samples or examples or books on this ?


Thanks in advance