NoteBlock API

-- NoteBlock Controller API
-- by MysticT

-- Config

-- id of the players
local tIds = {}
-- number of notes per player
local nNotes = 0

-- Instruments
piano = 1
bass = 2
bass_drum = 3
snare_drum = 4
click = 5

local function send(id, t)
    rednet.send(id, "<PLAY> "..textutils.serialize(t))
end

--[[
i: instrument (1-5)
n: note (0-24)
--]]
function playNote(i, n)
    local t = {}
    t[i] = { n }
    local id = tIds[math.floor(n / nNotes) + 1]
    send(id, t)
end

--[[
i: instrument (1-5)
notes: { n1, n2, n3, ..., nN}

n: note (0-24)
--]]
function playChord(i, notes)
    local ts = {}
    for _,n in ipairs(notes) do
        local id = tIds[math.floor(n / nNotes) + 1]
        if not ts[id] then
            ts[id] = {}
        end
        if not ts[id][i] then
            ts[id][i] = {}
        end
        table.insert(ts[id][i], n)
    end
    for id, v in pairs(ts) do
        send(id, v)
    end
end

--[[
Table format:
t = {
[i1] = { n1, n2, n3, ..., nN },
[i2] = { n1, n2, n3, ..., nN },
...
[iN] = { n1, n2, n3, ..., nN }
}

i: instrument (1-5)
n: note (0-24)
--]]
function play(t)
    local ts = {}
    for i, notes in pairs(t) do
        for _,n in ipairs(notes) do
            local id = tIds[math.floor(n / nNotes) + 1]
            if not ts[id] then
                ts[id] = {}
            end
            if not ts[id][i] then
                ts[id][i] = {}
            end
            table.insert(ts[id][i], n)
        end
    end
    for id, v in pairs(ts) do
        send(id, v)
    end
end

--[[
Table format:
t = {
[1] = n,
[2] = n,
[3] = n,
...
[N] = n,
["delay"] = d,
}

d: delay (in seconds), default 0.5
n: instrument-notes table (play() format, see above)
--]]
function playSong(t)
    local nDelay = t.delay or 0.5
    for _,n in ipairs(t) do
        play(n)
        sleep(nDelay)
    end
end