//==========================================================================
//
// S_GetRolloff
//
//==========================================================================

float S_GetRolloff(FRolloffInfo *rolloff, float distance, bool logarithmic)
{
    if (rolloff == NULL)
    {
        return 0;
    }

    if (distance <= rolloff->MinDistance)
    {
        return 1;
    }
    if (rolloff->RolloffType == ROLLOFF_Log)
    { // Logarithmic rolloff has no max distance where it goes silent.
        return rolloff->MinDistance / (rolloff->MinDistance + rolloff->RolloffFactor * (distance - rolloff->MinDistance));
    }
    if (distance >= rolloff->MaxDistance)
    {
        return 0;
    }

    float volume = (rolloff->MaxDistance - distance) / (rolloff->MaxDistance - rolloff->MinDistance);
    if (rolloff->RolloffType == ROLLOFF_Custom && S_SoundCurve != NULL)
    {
        volume = S_SoundCurve[int(S_SoundCurveSize * (1 - volume))] / 127.f;
    }
    if (logarithmic)
    {
        if (rolloff->RolloffType == ROLLOFF_Linear)
        {
            return volume;
        }
        else
        {
            return float((powf(10.f, volume) - 1.) / 9.);
        }
    }
    else
    {
        if (rolloff->RolloffType == ROLLOFF_Linear)
        {
            return float(log10(9. * volume + 1.));
        }
        else
        {
            return volume;
        }
    }
}