Some questions about texture functions of d3dx8/9

[Jérôme Gardou]

I'm trying to implement the D3DXGetImageInfoFrom* functions in d3dx8/9 dlls, 
and I have a few questions.

As there is no related source file from this kind of functions, I created 
texture.c within dlls/d3dx8. I guess this is the way you want it, but I'd 
like to hear it from you. 

Then I need libpng to handle this. I know that gdi32 has some (limited) 
support for this files, but I wasn't able to know how it was included in its 
code. A simple #include <png.h> doesn't work, as I expected. So I would like 
to know how wine build process handle third party libraries.

Then, I'd like to know what you think about the code attached here. Please 
don't forget that this is the very first time I make some code for wine !

Cheers.
Jérôme