[PATCH v2 2/6] wined3d: Add a real implementation of wined3d_check_device_multisample_type().

[Matteo Bruni]

2016-01-18 15:50 GMT+01:00 Henri Verbeet <hverbeet at gmail.com>:
> I finally had a look at D3D FSAAViewer on Windows, and I think this
> makes sense in general.
>
> On 14 January 2016 at 00:00, Matteo Bruni <mbruni at codeweavers.com> wrote:
>> +static inline unsigned int popcount(unsigned int v)
>> +{
>> +    v -= v >> 1 & 0x55555555;
>> +    v = (v & 0x33333333) + (v >> 2 & 0x33333333);
>> +    return ((v + (v >> 4)) & 0x0f0f0f0f) * 0x01010101 >> 24;
>> +}
>> +
> This is probably at least as good as the existing count_bits(), but it
> does duplicate that function.

I had the feeling we have a similar function already but somehow I
couldn't see it...

> GCC's __builtin_popcount() may also be
> worth a look. I'd probably call it wined3d_popcount() for consistency
> with e.g. wined3d_log2i().

I'll have a look and come up with a v2 hopefully soon.

BTW, technically the GL_SAMPLES and GL_NUM_SAMPLE_COUNT query are also
part of ARB_internalformat_query. I haven't bothered adding a separate
extension check for that but I can if you feel it's worthwhile.