FadeIn Effect for Music

Newbie & Debugging Questions
#1

Hello! I’m creating a game with Slick2D library, and I have a problem to calculate fadeIn effect for a volume of the music. Sadly, class Music has a fadeOut method fade(duration, endVolume, stopAfterFade), but does not contain and fadeIn.
So I want to increase volume from 0.0f to 1.0f in 3s.


if (gameContainer.isMusicOn()) {
    if (!music.playing()) {
        music.play(1.0f, 0.0f);
    }
    
    int fadeInDuration = 3000;
    if (startTime + fadeInDuration > gameContainer.getTime()) {
        float increaseVol = music.getVolume() + 0.1f;        
        music.setVolume(vol);
    }
}