CTor with a Texture and the boolean flag if you want a depthBuffer
Bind the current FBO. This is mostly done automatically.
Clears the content of the FBO.
Draw a Drawable on the current render target
Set a new Texture to the FBO which is now the new render target.
Unbind the current FBO. This is mostly done automatically.
A FrameBufferObject is usefull if you want to blit Drawables on a Texture. You create an FBO, set an Image/Texture to it and draw what you want. After drawing it is on your Texture.