[Mesa-dev] Mesa (d3d1x): d3d1x: add new Direct3D 10/11 COM state tracker for Gallium

[Henri Verbeet]

On 21 September 2010 13:13, Luca Barbieri <luca at luca-barbieri.com> wrote:
> Why are you claiming this?
> I assume it's because of the comment in tpf.h, which states that it
> has been written according to Microsoft's documentation, which is
> available solely from reading the d3d11TokenizedProgramFormat.h header
> in the DDK.
> Using the header, which is documented in the DDK documentation as the
> place to look for documentation of the format, as reference, doesn't
> seem to me unusual or problematic.
>
...
> Could you please explain your concerns in more detail?
>
The basic rule Wine uses is that if you've ever seen Microsoft code,
you can't work on similar code for Wine. That may or may not be more
strict than would legally be required in a given jurisdiction, but
Wine simply doesn't want to take that risk. I think Bridgman expressed
the issue fairly well at some point as "Stay well back from the
abyss".

The only reason we can look at e.g. PSDK headers at all is because you
can't copyright facts like constant values or structure layouts. Even
then, we have to be very careful to only take the facts from the
header and not anything that would be considered "expression".
Non-trivial macros would probably be considered code. Wine certainly
wouldn't go through all the trouble of figuring out the formats from
scratch if we considered looking at the DDK implementation an
acceptable risk. Also, at least a couple of years ago the license for
the DDK explicitly restricted its use to Windows development. That's
again something that may or may not hold up, but we're not going to
try.

Note that I've looked at neither the DDK nor your actual
implementation. The fact that apparently you looked at the DDK while
writing the code makes me cautious to avoid it.