what avaialble methods are available in OGL for offscren rendering?
i am currently reading up on pbuffers, but have also heard of uber/super buffers?
im looking for the most standard with regards to opengl 2 (ie whats panned to be standard) if ya get what i mean.
im currently working on shadow mapping so gonna need depth info also in the buffer
seems pbuffers are windows only? looking in wglext.h looks as if its using win32 variables like HDC, which i dont want!
Offscreen rendering done (faked) in the most compatible way :
render to backbuffer, and glTexCopySubImage to your texture. Easy, reasonably fast, and very well supported. But you need an actual visible windows, obscured parts are undefined, so this is not 'true offscreen rendering.
pbuffers : complex to program, but works on windows and apparently on linux too, check glx stuff (wglext.h is indeed windows only). You have to code both path differently though.
You may check my website and my tries on render-to-texture stuff, both with windows’ pbuffers and glCopyTexSubImage :
http://www.chez.com/dedebuffer/
OpenGL 2.0 method : well forget about uber/super buffers, they are not in.
See this thread about the future child of the never born uberbuffers and EXT_render_target :
http://www.opengl.org/discussion_boards/cgi_directory/ultimatebb.cgi?ubb=get_topic;f=3;t=011406