如何在OpenAL中调整声音的音量？

Question

如何调整OpenAL声音库中声音的音量？

Answer 1

float newVolume = 0.4f;
alSourcef(currentSourceID, AL_GAIN, newVolume);

Answer 2

void Listener::setVolume(float v)
{
    Assert::isTrue(0 <= v && v <= 1);
    alListenerf(AL_GAIN, v);
}

float Listener::getVolume()
{
    ALfloat v;
    alGetListenerf(AL_GAIN, &v);
    return v;
}