IGameInputDevice::GetSupportedLightingGroupSize

uint32_t GetSupportedLightingGroupSize(
    GameInputLightingGroups group
);

void SetFaceButtonGradient(IGameInputDevice* device) noexcept
{
    const uint32_t lampCount = device->GetSupportedLightingGroupSize(GameInputLightingGroupFaceButtons);
    for (uint32_t i = 0; i < lampCount; ++i)
    {
        const uint8_t green = static_cast<uint8_t>(255 * (i + 1) / lampCount);
        device->SetLightingColor({ 0, green, 0 }, GameInputLightingGroupFaceButtons, i);
    }

    device->ApplyLightingColors();
}