def closestChord(allFrets, bestChords, allChords):
# this method is basically a rough adaptation of
# how I remembered the shorest path algorithm.
# Each level of recursion that a chord goes down
# adds another note to it. If best chords have
# 5 chords in it then the best 5 chords have been made,
# so exit and if allchords is empty then
# all combinations have been tried to exit
if ((len(bestChords) == 5) or (len(allChords) == 0)):
return
# get the chord with the lowest score from heap
chord = heapq.heappop(allChords)
# if the chord holds all of the notes in it then it is finished
if (len(allFrets) <= chord.numNotes):
# this for loop sees if the finished
# chord is a duplicate, if so move on
for x in range(0, len(bestChords)):
if chord.__eq__(bestChords[x]):
# continue recursion
closestChord(allFrets, bestChords, allChords)
return # tail recursion
bestChords.append(chord) # add the finished chord to the list
closestChord(allFrets, bestChords, allChords) # continue recursion
return # tail recursion
numNotes = chord.numNotes # finds which note the chord is on
# the loop gets the frets of the next note to be
for y in range(0, len(allFrets[numNotes])):
# makes sure that the string that the fret is on is not in use
if (chord.frets[allFrets[numNotes][y].string] is None):
# this makes sure the note being added
# is not lower than the bass note
if (chord.bass <= allFrets[numNotes][y].note.numValue):
# add fret to chord
chord.frets[allFrets[numNotes]
[y].string] = allFrets[numNotes][y]
# create a new chord to add the new fret onto
tempChord = Chord(chord.frets)
tempChord.bass = chord.bass # set the bass note of new chord
# creates a new chord using the base chord's notes so that
# the base chord can be altered without altering the new chord
# Push it onto the heap
heapq.heappush(allChords, tempChord)
# remove the fret from the base chord so that other
# frets on the note can be added to the chord
chord.frets[allFrets[numNotes][y].string] = None
closestChord(allFrets, bestChords, allChords) # continue recursion
return # tail recursion
def chordCreate(notes, tuning, numFrets, targetFret, low, high, fretsOnStrings,
isBass):
app.logger.debug('in chordCreate')
# list that will hold all of the possible frets that
# can be played with the given notes
allFrets = []
for note in notes:
# returns the frets that each note can be played on
frets = getFrets(note, tuning, numFrets, targetFret, low, high)
frets = sortStuff(frets) # sort the frets by distance to the target
for fret in frets:
# makes sure not to add duplicate frets
# if the user say has two of the same note
if fret not in fretsOnStrings[fret.string]:
# this will store all of the frets that
# can be played on each string for the ui
fretsOnStrings[fret.string].append(fret)
allFrets.append(frets)
strings = [None] * 6 # create a 6 unit long list full of None
baseChord = Chord(strings) # This is a chord with no notes in it
bestChords = [] # stores the five best chords
allChords = [] # stores all of the chords that get created in method
# creates chords that each hold only one fret of the first note
if (len(allFrets) > 0):
for fret in allFrets[0]: # get each possible fret of the first note
# add the fret of the first note to the baseChord
baseChord.frets[fret.string] = fret
# create a new chord with the strings
tempChord = Chord(baseChord.frets)
if (bool(isBass)):
# if the user wants to use a bass note this will set it,
# it is intialized to 0 otherwise
tempChord.bass = fret.note.numValue
heapq.heappush(allChords, tempChord) # heap push it to allChords
# remove the fret so that the chord is empty again
baseChord.frets[fret.string] = None
# this is the method that finds the best chords
closestChord(allFrets, bestChords, allChords)
if len(bestChords) >= 1: # this means at least one chord was found
return bestChords
# The chord is not possible to make
errorStrings = []
for x in range(0, 6):
errorStrings.append(Fret(-1, -1, 100, Note(0)))
bestChords.append(Chord(errorStrings))
# returns an array holding only one chord with no notes in it
return bestChords
