Function AllocFilter

3rdparty/openal/al/filter.cpp:309–327

ALfilter *AllocFilter(ALCdevice *device)
{
    auto sublist = std::find_if(device->FilterList.begin(), device->FilterList.end(),
        [](const FilterSubList &entry) noexcept -> bool
        { return entry.FreeMask != 0; }
    );
    auto lidx = static_cast<ALuint>(std::distance(device->FilterList.begin(), sublist));
    auto slidx = static_cast<ALuint>(CTZ64(sublist->FreeMask));

    ALfilter *filter{::new (sublist->Filters + slidx) ALfilter{}};
    InitFilterParams(filter, AL_FILTER_NULL);

    /* Add 1 to avoid filter ID 0. */
    filter->id = ((lidx<<6) | slidx) + 1;

    sublist->FreeMask &= ~(1_u64 << slidx);

    return filter;
}

void FreeFilter(ALCdevice *device, ALfilter *filter)
{