random.js

inlets = 1;
outlets = 3;

Gm_triad = triad(7,false) //notes of Gm chord
Gm_scale = scale(7,true,true)
F_triad = triad(5,true) //notes of F chord
F_scale = scale(5,true)
D_triad = triad(2,true) // notes of D chord
special = pentatonic(0,true)

bass = [55,53,50,0] //bass notes (not implemented)

last_mode = 1
last_note = 76
displacement = 0
last_movement = 0

//below is dictionary of MIDI number to note name
notes = {0:"C", 1:"C#", 2:"D", 3:"D#", 4:"E", 5:"F", 6:"F#", 7:"G", 9:"A", 10:"Bb", 11:"B"}

min_octave = 4
max_octave = 7

function get_note(mode) {
    offset = 0
    post(mode)
    post(offset)
    //offset = 0
    modes = [Gm_triad,F_triad,D_triad,special]
    mode = modes[mode]//selects the mode we are in
    sorted_mode = []
    for (i=0; i<mode.length; i++){
        sorted_mode.push(mode[i]%12)
    }
    a.sort //puts the mode in sorted value (for octave reasons)


    last_pitch = last_note%12 //gets the previous pitch we used
    last_octave = Math.floor(last_note/12) //previous octave we were in

    index = sorted_mode.indexOf(last_pitch); //where the last pitch is in the mode

    note_shift = 0 //how much we will move the pitch
    octave_shift = 0 //how much we will move the octave
    movements = [0,1,2,3,4] //possibly movements (positive or negative)
    movement_probabilities = [1.5,5,2,3.5,2] //probability of hitting each note (weighted, so 5 is 5x more likely than 1)


    position=0 //current movement we could be at
    random_num = random_float(0,list_sum(movement_probabilities)) //random number placed between one of these movements

    post("random num: ")
    post(random_num)
    for (i=0; i<movements.length; i++){
        position += movement_probabilities[i]

        if (random_num < position){ //if the number is that movement
            note_shift = movements[i] //make that the note shift
            break
        }
    }
    d = .3*sign(last_movement) // -.3 or +.3
    s = Math.random() //random number between 0 and 1

    if (s>.5+d){ //if that random number is greater than .5+d, it will go in the negative direction
        //this is so when there is a downward trend, it is more likely that it will go down than up, and vice versa
        note_shift = note_shift*-1
    }
    post("amount moving: ")
    post(note_shift)

    //the new note is the old index plus however many the note shifted, wrapped around (and positive)
    new_note = sorted_mode[Math.abs((index+note_shift)%mode.length)]

    post ("new pitch: ")
    post(new_note)

    //the octave shift is the old octave shift, plus however much the shift made it go up or down
    octave_shift = last_octave + Math.floor((index+note_shift)/mode.length)

    if (octave_shift<min_octave){
        octave_shift = last_octave+1
        note_shift = -1*(last_movement) + 3
        post("too low!")
    }
    else if (octave_shift>max_octave){
        post("Too high!")
        octave_shift = last_octave-1
        note_shift = -1*(last_movement) - 3
    }

    new_note = new_note + 12*octave_shift + offset

    last_note = new_note
    last_movement = note_shift



/*  note = mode[random(0,3)]; //chooses a random note from the mode
    midi_value = note+(12*random(min_octave,max_octave+1))

    outlet(1,midi_value); // puts in outlet 1 that note from 4-8 octaves above
    outlet(0,notes[note%12]); //puts the name of that note in outlet 0
    outlet(2,toHz(midi_value)) */

    outlet(1,new_note);
    outlet(0,notes[new_note%12])
    outlet(2,toHz(new_note))
}

function random(min,maximum){
    //simple function that returns a number within the min/max bounds
    return Math.floor(Math.random()*(maximum-min)+min);
}

function random_float(min,maximum){
    return Math.random()*(maximum-min)+min
}

function toHz(midi){
    return Math.pow(2,(midi-69)/12)*440
}

function triad(midi, major){
    add = 0
    if (major){
        add=1
    }
    return [midi,midi+3+add,midi+7]
}


function scale(midi, major, harmonic){
    add=0
    seventh=0
    if (major){
        add = 1
    }
    else{
        if (harmonic){
            seventh=1
        }
    }
    L = [midi,midi+2, midi+3+add, midi+5, midi+7, midi+8+add, midi+10+add+seventh, midi+12]
    return L
}

function pentatonic(midi,major){
    add = 0
    if (major){
        add=1
    }
    return [midi, midi+2, midi+3+add, midi+7, midi+8+add, midi+12]
}

function sign(n){
    if (n<0){
        return -1
    }
    else if (n>0){
        return 1
    }
    else{
        return 0
    }
}

function list_sum(L){
    sum=0
    for (i=0; i<L.length; i++){
        sum+=L[i]
    }
    return sum
}