this sounds extremely weird to me but, believe it or not, i’m getting light positions in world space on ati boards when using arb_fragment_program and asking for state.light[x].position
i always thought light vectors were transformed by the current mv matrix when calling a glLightfv command, and actually this is what i get on nv boards in the same test application
vertex programs are working fine instead (returns eye space position)
can anyone confirm this?
oh btw i am using the latest omega drivers, based on CATALYST 5.1 Driver Build 184.108.40.20605
thanks for any help you may provide
this is something i ran into a few weeks ago as well… but not only that state.light[x].position seems to be wrong within an arb_fp (and correct in an arb_vp) also the modelview matrix in a fragment program seems not to be correct…
i tested this by writing a vertex program that was passing one row of the modelview matrix as color and comparing the results to a fp that did the same… in the fp the modelviewmatrix seemed to be the inverse of the true modelviewmatrix.
sheez, you are definitely right, i’ve been trying to output row of texmatrix, and ati fps actually output column 0, while vps output row 0
is this the way it’s meant to be?!?
on the other side, nv boards show coherent behaviour between vps and fps
This is one of multiple fragment program bugs that I reported to ATI months ago. If it isn’t fixed by now I don’t expect it to ever be fixed. That’s why I have an NVidia card now
Yes, that may have been a bit harsh. I’ll start a flame war if I’m not careful I guess I also switched because I got tired of waiting for GLSL support under Linux. I almost never use arb_vp and arb_fp anymore; GLSL is too much fun.
so, is there any chance this could be fixed in the near future? how do i report this to ati driver team?
I’ve found that they listen better if you include a program that is easy to run to see the problem; ideally in source.
thanks for your reply
i have already sent em an email saying i may provide some test app if needed
but i think they should definitely be aware of it judging by the gravity of the problem and by the number of people experiencing it