punymusiclang.lua

local comp = require('component')
local snd = comp.sound
local tap = comp.tape_drive
local no = require('note')
local thrd = require('thread')
local tbl = require('table')
local sh = require('shell')
local fs = require('filesystem')

local args, opts = sh.parse( ... )

if opts.t then
  print("Tape mode")
elseif opts.f then
  print("File mode")
else
  print("Usage: punymusiclang [-t][-f <filename>]")
  print("You must write exactly one of (-t/-f)")
  print("If you use both, the program is written to crash itself.")
  os.exit()
end

local commsize = 2
channs = 4

local channadsr = {[1]={[1]=0,[2]=0,[3]=0,[4]=0,['chg']=false},
[2]={[1]=0,[2]=0,[3]=0,[4]=0,['chg']=false},
[3]={[1]=0,[2]=0,[3]=0,[4]=0,['chg']=false},
[4]={[1]=0,[2]=0,[3]=0,[4]=0,['chg']=false},
[5]={[1]=0,[2]=0,[3]=0,[4]=0,['chg']=false},
[6]={[1]=0,[2]=0,[3]=0,[4]=0,['chg']=false},
[7]={[1]=0,[2]=0,[3]=0,[4]=0,['chg']=false},
[8]={[1]=0,[2]=0,[3]=0,[4]=0,['chg']=false}}

function setChanns(chn)
  channs = chn
end

function rnoteplay(midn, chn)
  if channadsr[chn].chg then
    channadsr[chn].chg = false
    local adsr = channadsr[chn]
    snd.setADSR(chn, adsr[1], adsr[2], adsr[3], adsr[4])
  end
  snd.close(chn)
  snd.open(chn)
  snd.setFrequency(chn, no.freq(midn) * 2)
end

function nnoteplay(midn, chn)
  snd.setFrequency(chn, no.freq(midn) * 2)
end

function noterel(chn)
  snd.close(chn)
end

function volume(vol, chn)
  snd.setVolume(chn, (vol / 255)*0.2)
end

function inst(inst, chn)
  snd.setWave(chn, inst)
end

function sattack(att, chn)
  channadsr[chn][1] = att * 8
  channadsr[chn].chg = true
end

function sdelay(del, chn)
  channadsr[chn][2] = del * 8
  channadsr[chn].chg = true
end

function ssustain(sus, chn)
  channadsr[chn][3] = (sus / 255)*0.2
  channadsr[chn].chg = true
end

function srelease(rel, chn)
  channadsr[chn][4] = rel * 8
  channadsr[chn].chg = true
end

if opts.t then
  tap.seek(-(tap.getSize()))
  tapesize = string.unpack("<I4", tap.read(4))
  re = tap
elseif opts.f then
  fil = fs.open(sh.resolve(args[1]), "rb")
  fil:seek("set", 0)
  filsiz = fs.size(sh.resolve(args[1]))
  filpos = 0
end

currChan = 1
tickwait = 1

function decComm(bytecomm, data)
  if bytecomm == 118 then
    setChanns(data)
    currChan = 1
    print("set channels to " .. data)
  elseif bytecomm == 100 then
    tickwait = data
    currChan = 1
    print("set line length to " .. data .. " ticks")
  elseif bytecomm == 130 then
    sattack(data, currChan)
  elseif bytecomm == 131 then
    sdelay(data, currChan)
  elseif bytecomm == 132 then
    ssustain(data, currChan)
  elseif bytecomm == 133 then
    srelease(data, currChan)
  elseif bytecomm == 155 then
    volume(data, currChan)
  elseif bytecomm == 144 then
    inst(data - 1, currChan)
  elseif bytecomm == 2 then
    rnoteplay(data, currChan)
  elseif bytecomm == 3 then
    nnoteplay(data, currChan)
  elseif bytecomm == 4 then
    noterel(currChan)
  elseif bytecomm == 0 then
    local linesize = commsize * channs
    if opts.f then
      fil:seek("cur", -((linesize * data) + 2))
      filpos = filpos - (linesize * data)
    elseif opts.t then re.seek(-(linesize * data)) end
    currChan = 1
  end
end

print("OK, starting")

tickstowait = 1

while true do
  tickstowait = tickstowait - 1
  if tickstowait <= 0 then
    while currChan <= channs do
      if opts.f then
        co = fil:read(2)
      else
        co = re.read(2) end
      --if co[2] == nil then
        --print("UNALIGNED FILE?")
        --os.exit()
      --end
      --if co and not (co:len() < 2) then
        comma, comval = string.unpack("<BB", co)
        decComm(comma, comval)
      --end
      currChan = currChan + 1
    end
    tickstowait = tickwait
  end
  currChan = 1
  snd.delay(50)
  snd.process()
  os.sleep(0.04)
end