Hello Marco,
Believe me, You do _not_ need to do such a thing. I have already made a
RT visual flight simulation as a part of my MSc thesis. Pls allow me to
"make some points"(forgive me if you are familiar with these facts):
* RTlinux modules have been used for dynamics calculation (using FP
calculations, with doubles), whereas I used OpenGL under X for graphics;
communication was via RT-FIFO-s.
* I had to interpolate (1D,2D and 3D interpolations) more than 35 tables
(and I did it every single pass) per derivatives calculation. State
vector consisted of 22 elements.
* I choose _very_ small integration step of 5ms (dynamics of landing
gear), and RK3 as a method of integration (as well as 4th order spline
interpolation). It took less than 300 microseconds to calculate state
vector for next time-point. Compared to 5ms of step time, it would be
6%. (6% of the time step has been used for dynamics calculation, and 94%
was free for graphics). (P II 300 MHz, 64MB, Voodoo3 3000 video card)
* I didn't even consider multistep methods, or RK2 method, or linear
interpolation, or lengthening the integration step (when dealing with RT
constraints). I didn't have to sacrifice correctness of the
calculations, RT constraints proved not to be problem.
* should you calculate AD derivatives (interpolation) every (let's say)
every 50ms and implement some kind of "subscheduler" for low frequency
dynamics,
you should make results _much_ more drastic. Of course, you might use
faster
computer as well.
In the light of this, I think (AFAIK) you really do not need RT
implementation of OpenGL.
Hope it helped a bit,
Gordan Sikic
mailto:[EMAIL PROTECTED]
marco zoncu wrote:
>
> Is it possible to use OpenGL libraries in a rtlinux
> task? I should not want to see my graphics scheduled
> in background (as a standard Linux process), 'cause
> I'm gonna write a VR application (or I hope so)!
> Thank U very much!
>
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