Hi all,
One of the most important missing feature in octave's "native" gl-renderer is the lack of an offscreen rendering option. After some searching, I had settled on using OSMesa, a part of the Mesa library which is used in most linux distros as the OpenGL implementation. Other solutions were not cross platform and it seemed to me that I would not be able to maintain them.
I tried implementing an offscreen backend based on OSMesa only to find out that it does not play well with the other OpenGL implementation that is used to render on-screen -- it re-implements all the OpenGL functions, so you can either link to OSMesa or to the system's GL libraries. This leads me to several possibilities:
1. Is it possible to link different oct files against different versions of libraties? -- i.e link offscreen_backend.oct to OSMesa and fltk_backend.oct to the system's GL? That would certainly solve the problem.
2. If not, another possibility is to compile OSMesa so that all OpenGL functions have the mgl prefix instead of the usual gl prefix (i.e. mglBegin instead of glBegin). This together with some scripted way to make a m-prefixed version of gl-render (to be called mgl-render of course!) might be a solution (all be it a very ugly one).
Does anyone else have any other ideas or recommendations?
Shai