Help needed for Wii and GameCube port #494

Hi there!
I'm trying to port OpenLara to the Wii (and later, GameCube -- these platforms are in most aspects identical), which now has working ports of SDL2 and OpenGL (via OpenGX), though the latter currently only supports up to OpenGL 1.5. I though that, given the number of platforms supported by OpenLara, this would be a very simple port, but it looks like I was too optimistic :-)

The concrete question is about OpenGL support: I see that there is a definition FFP ("Fixed Function Pipeline", I guess), which I interpreted as being a synonym for "OpenGL < 2.0", but after a few attempts at building the project, I'm getting more and more convinced that either I misinterpreted the meaning of this macro or, (more likely) its support is incomplete. For example, I see that the cacheRenderTarget() function makes use of OpenGL 3 framebuffers, and there are no guards with the FFP condition.

What is the meaning of that macro, and am I right in believing that the gapi/gl.h file with the FFP define is the right way to implement a OpenGL 1.5 port?

Just for reference, here's my branch (currently not building): https://github.com/mardy/OpenLara/tree/wii