[Mesa-dev] Building Mesa for Windows using Visual Studio

[Jose Fonseca]

On 14/04/15 13:41, Emil Velikov wrote:
> Hi Shervin,
>
> On 14 April 2015 at 00:22, Shervin Sharifi <shervin0 at gmail.com> wrote:
>> Hi,
>>    I tried to use Mesa (compiled with MSVC) to run OpenGL ES content on
>> Windows . I ran into a few problems.
>>    I don't know if this is the right way of reporting issues, but thought
>> people may be interested to know.
>>
> Another thing would be to file a bug report, although most people
> appreciate patches (send via git send-email) even more :-)
>
>>   Here's a piece of code in functions _mesa_dlopen(const char*, int) in
>> src\mesa\main\dlopen.h  (same problem happens with function _mesa_dlsym(void
>> *, const char *) in the same file).
>>
>>   The original code returns NULL and doesn't load the library if the code is
>> compiled with Visual Studio.
>>
> True but is the library, that is to be opened, there in the first
> place ? Last time I've looked nothing seriously bad was happening
> (apart from the missing EXT_texture_compression_s3tc and
> ANGLE_texture_compression_dxt extensions) when we fail to open the
> dxtn library.
>
> Cheers,
> Emil
>
>>   #if defined(HAVE_DLOPEN)
>>     flags = RTLD_LAZY | RTLD_GLOBAL; /* Overriding flags at this time */
>>     return dlopen(libname, flags);
>> #elif defined(__MINGW32__)
>>     return LoadLibraryA(libname);
>> #else
>>     return NULL;
>> #endif
>>
>>   Adding the following lines to the code resolves the problem:
>>
>> #elif defined(_WIN32)
>>     return LoadLibraryA(libname);
>>
>>   Thanks,
>>       Shervin
>>


Yep, the C-pre-processor logic is wrong.

But as Emil said, unless you actually have a Windows build of the 
libtxc_dxtn library it won't make any difference in practice.

Jose