Multi-platform render-to-texture?

Hello. Today I wanted to implement render-to-texture functionality in my GL renderer, but then I saw something terrible: All the optimal solutions involved some kind of WGL* extension... The problem is, that I want to make my engine portable, and I would be very happy if I could avoid too much platform specific code. Is the only solution to render using the ordinary color buffer, and then copy (:-O) to a texture? Have I missed something? (I certainly hope so) Sure, I''m going to use WGL_ARB_pbuffer on the Windoze-build, but personaly I think it stinks that the Linux version is going to be slower than the Windoze-one, and there''s nothing I can do about it -- Rasmus Neckelmann royal.adsl.dk