[PATCH 3/5] opengl32: Fix extension checks on OpenGL core profile contexts.

[Matteo Bruni]

2015-01-05 18:33 GMT+01:00 Henri Verbeet <hverbeet at gmail.com>:
> On 5 January 2015 at 17:17, Matteo Bruni <mbruni at codeweavers.com> wrote:
>>  static BOOL has_extension( const char *list, const char *ext, size_t len )
>>  {
>> +    if (!list)
>> +    {
>> +        const struct opengl_funcs *funcs = NtCurrentTeb()->glTable;
>> +        const char *gl_ext;
>> +        unsigned int i;
>> +        GLint extensions_count;
>> +
>> +        glGetIntegerv(GL_NUM_EXTENSIONS, &extensions_count);
>> +        for (i = 0; i < extensions_count; ++i)
>> +        {
>> +            gl_ext = (const char *)funcs->ext.p_glGetStringi(GL_EXTENSIONS, i);
>> +            if (!strncmp(gl_ext, ext, len) && !gl_ext[len])
>> +                return TRUE;
>> +        }
>> +        return FALSE;
>> +    }
>> +
> If I'm reading this correctly, this effectively ignores
> DisabledExtensions for anything newer than GL 3.0. (And at least as
> far as wglGetProcAddress() is concerned it affects both compatibility
> and core contexts.)

Hmm, it should still work via filter_extensions(). On the other hand
we don't filter the extensions the application queries through
glGetStringi(GL_EXTENSIONS, i), so yeah, that is missing and I should
add that (maybe in a separate patch?)

>> +    gl_version = (const char *)glGetString(GL_VERSION);
>> +    sscanf(gl_version, "%u", &major);
>> +    if (major >= 3)
>> +    {
> It seems tempting to just flag the context in
> wglCreateContextAttribsARB() under the appropriate conditions, perhaps
> in a similar way to wgl_handle_type. Not sure if it would really make
> it better though.

I'm going to give it a try and see how it looks.

> As an aside, note that winex11.drv also uses
> "glGetString(GL_EXTENSIONS);" in X11DRV_WineGL_InitOpenglInfo().

That should be fine, that's always a compatibility context created
with glXCreateContext().