Query the fading status of the music stream.
Defined in <SDL3_mixer/SDL_mixer.h>
Mix_Fading Mix_FadingMusic(void);(Mix_Fading) Returns the current fading status of the music stream.
This reports one of three values:
If music is not currently playing, this returns MIX_NO_FADING.
This function is available since SDL_mixer 3.0.0.