[ODE] Particle/cloth/skeleton (was: Re: Choleski factorization)

[gl]

> I've always wondered if it would make any sense to use Windows' Direct3D
vector
> and matrix operations on Win32 platforms.  If they by chance use SIMD
> instructions etc, you'd get that for free, and in the distant future, when
the
> Pentium XXIV has single-cycle matrix multiplies, you'd get that for free
with no
> code changes.

Be nice for all us win guys, that's for sure : ).  There is some processor
specific optimisation going on in D3DX (the DX utility library that provides
quat, matrix and various vector classes/functions, amongst others), and yes,
you do get it transparently and its updated over time.  Using that library
doesn't tie you to any other parts of DX in any way (eg. there are no
rendering dependencies).

It's not clear though exactly what they've optimised - their vec3
equivialent doesn't use padding, so they probably only accelerate a few
complex operations.  Matrices should be (you can use an aligned version),
not sure about quats.  They do intend to keep adding optimisations in key
areas though.
--
gl