Re: string.sub still failing, problem seems a bit weird...

[Jan Kratochvíl <jan.kratochvil@...>]

> > I actually zoomed in to a call to DirectX9-s CreateDevice() (which 
> > returns
> > successfully, I don't think it is memory leaking / writing in invalid
> > places). *Right* before CreateDevice() string.sub works, *right* after
> > CreateDevice(), string.sub fails.
>
>
> This could be the FAQ where DirectX sets the FPU precision to
> single, which starts to clobber double lua_numbers.  I think
> there was a thread about it quite recently (or maybe I'm mixing
> up this list with one of the many others where people get frequently
> hit by the same DirectX misdesign... sigh...).
It was this list :).

> There's a DirectX init flag which causes DirectX calls to preserve
> the FPU state, which is anecdotally a speed hit but avoids the
> problem.  Using OpenGL is also a pretty good workaround. :D
Exact name of this flag is GCF_FPUPRESERVE. Can it be part of lua FAQ? :)
Using OpenGL is surely most safe workaround :) but if you really want 
DirectX
you can use lua with floats instead of doubles or you can pass this 
magic directx flag.
In documentation (msdn) are few lines about speed but I made few tests 
and can't
tell you the difference between using and not using this flag. Maybe it 
is some dinosaur from
fixed function pipeline era :-))

Jan Kratochvil
Illusion softworks, a.s.