from os import path,getenv

def root():

    r = getenv("LIGHT9_SHOW")

    if r is None:

        raise OSError("LIGHT9_SHOW env variable has not been set to the show root")

    return r

def musicDir():

    return path.join(root(),"music")

def curvesDir():

    return path.join(root(),"curves")

def songFilename(song):

    return path.join(musicDir(),"%s.wav" % song)

def subtermsForSong(song):

    return path.join(root(),"subterms",song)

def subFile(subname):

    return path.join(root(),"subs",subname)

def subsDir():

    return path.join(root(),'subs')

def patchData():

    return path.join(root(),"patchdata.py")