How to find rendering code

[Markus]

Hi,

I am new to Wine development and wanted to ask on the list, whether someone 
could point me to the correct place where the code for issues 3 and 4 in 
http://bugs.winehq.org/show_bug.cgi?id=7273 might be located. It looks like 
the solution could be rather straightforward to implement but I have no idea 
how to find the respective rendering method.

Any help would be greatly appreciated.
Thanks.