En me baladant sur opengl.org j´ai trouvé un post a propos des gens de SGI qui partaient chez Microsoft
où d´ailleurs Mark Kilgard donne un point de vue interessant sur le devenir d´OpenGL, et puis en etant parti sur le sujet des grands constructeurs ou developpeurs
je tombe sur ça:
" I used Cg but I removed it against GLSL mainly because the resulting code didn´t work properly in ATI cards, and because the lack of support: my ´assigned´ developer relations at that time finished a two months ´please, wait´ emails with one ´we are too busy at the moment, I will try to answer you in a near future´ ( a future that never came). It was a problem of invariance not working on GFFX cards.
Seeing all the problems with GLSL on non-NVIDIA boards, I agree with you that maybe an intermediate pseudo-assembly could be good. But some problems arise: who will be the implementer of the intermediate compiler? The ARB? How many time will then be necessary to have the first version ( that will not make happy to any of the ARB members, including NVIDIA)?
In the case of D3D it is clear that it will MS. But in OpenGL…
How many time will it take for every new version of the assembly language extensions ( arb_fragment_program2/arb_vertex_program2)? And, will them be really useful or will them become a least common denominator between ATI, NVIDIA and 3DLabs?
For example, Will it include instructions like NRM? Or should we imagine that the ‘unified compiler’ will identify the group of instructions and will convert then to a NRM instruction?
For instance, there are similar problems ( or even more) using the assembly extensions in ATI cards than using GLSL. You have to take care about instruction order, about texture indirections, …
It is good to hear from you. I would like to see a conference/tutorial from you at GDC, like some years ago. I think you are a good communicator."
Je comprend mieux pourquoi j´ai du mal avec le Cg et ATI ! Je savais évidemment que ce n´etait pas top étant donné l´appartenance du Cg a Nvidia, mais si les developpeurs professionnels s´y mettent aussi j´ai moins de chance d´arriver a faire quelque chose de compatible Nvidia < => ATI...
Alors dites-moi, quel futur pour le Cg ? Si ça continue je vais me mettre au GLSL lol..