index.js

var fs = require('fs')
var mkdirp = require('mkdirp')
var cpr = require('cpr')
var Note = require('octavian').Note

var Notes = require('./lib/notes')
var songHeaders = require('./lib/song-headers')
var noteTiming = require('./lib/timing')

var buildDir = 'build/'
var libAsmDir = __dirname + '/lib/asm'

function genSongHeader (options) {
  options = options || {}
  var channels = [
    'square1',
    'square2',
    'triangle',
    'noise'
  ]

  var header = []
  header.push('song{i}_header:')
  header.push('\t.byte $0' + songHeaders['streamCount'])

  channels.forEach(function (channel) {
    var channelHeader = genChannelHeader(channel, options)
    header.push(channelHeader)
  })

  return header
}

function prependByte (prop) {
  return prop ? '\t.byte ' + prop : ''
}

function genChannelHeader (channel, options) {
  var channelOptions = songHeaders[channel]
  var name = channelOptions && channelOptions.name
  var enabled = channelOptions && channelOptions.enabled ? '$01' : '$00'
  var channelName = channelOptions && channelOptions.channel
  var duty = channelOptions && channelOptions.duty
  var ve = channelOptions && channelOptions.ve
  var pointer = channelOptions && channelOptions.pointer
  var tempo = (options && options.tempo && options.tempo[channel]) || (channelOptions && channelOptions.tempo)

  var channelHeader = [
    prependByte(name),
    prependByte(enabled),
    prependByte(channelName),
    prependByte(duty),
    prependByte(ve),
    '\t.word ' + pointer,
    prependByte(tempo)
  ]

  return channelHeader.join('\n')
}

var songs = []
var index = 0

function Song (options) {
  if (!(this instanceof Song)) {
    return new Song(options)
  }
  this.prefix = 'song' + index + '_'

  this.isLooped = false

  this.notes = Notes(this.prefix)
  this.square1 = this.notes.square1.bind(this.notes)
  this.square2 = this.notes.square2.bind(this.notes)
  this.triangle = this.notes.triangle.bind(this.notes)
  this.noise = this.notes.noise.bind(this.notes)

  this.options = options ? options : {}
  this.timing = options && options.timing || 1 / 8
  this.song = ''
  index++
}

Song.prototype.note = function note (n) {
  var note = new Note(n)
  return note
}

Song.prototype.loop = function loop () {
  this.isLooped = true
  return this
}

Song.prototype.done = function done () {
  var self = this
  var codeMap = self.notes.code
  var tempMap = self.notes.temp
  var channels = ['square1', 'square2', 'triangle', 'noise']

  var i = songs.length
  var header = genSongHeader(self.options)
  var songHeader = header.map(function (line) {
    return line.replace('{i}', i)
  }).join('\n')

  self.song += '\nmain_loop:\n'

  channels.forEach(function (channel) {
    var currentCode = self.notes.current === channel ? self.notes.currentCode : ''
    var code = codeMap[channel] + tempMap[channel].replace(/\{loop\d\}/gm, '') + currentCode.replace(/\{loop\d\}/gm, '')
    if (!self.isLooped) {
      code += endSound()
    }
    self.song += code.replace(/\{time\}/gm, noteTiming[self.timing])
  })

  if (self.isLooped) {
    self.song += '\n\t.byte loop\n\t.word ' + 'main_loop\n'
  }
  var song = songHeader + '\n\n' + self.song
  songs.push(song)
}

function endSound () {
  return '\n\t.byte endsound\n'
}

function buildSongs (err) {
  var soundEnginePath = buildDir + '/sound_engine.s'
  var songsOut = '\nNUM_SONGS = $0' + songs.length // kinda hacky :(
  var words = []
  var includes = []
  songsOut += '\n\nsong_headers:\n'

  if (!err) {

    cpr(libAsmDir, buildDir, function (err, files) {
      if (err) {
        console.error(err)
      } else {
        songs.forEach(function (song, i) {
          var filePath = buildDir + '/song' + i + '.i'
          var word = '\t.word song' + i + '_header\n'
          var include = '\t.include "song' + i + '.i"\n'

          fs.writeFile(filePath, song, function (err) {
            if (err) {
              console.error(err)
            }
          })

          words.push(word)
          includes.push(include)
        })

        words.forEach(function (w) {
          songsOut += w
        })

        songsOut += '\n\t.include "sound_opcodes.s"\n'
        songsOut += '\n\t.include "duty.s"\n'
        songsOut += '\n\t.include "note_table.i"\n'
        songsOut += '\n\t.include "note_length_table.i"\n'
        songsOut += '\n\t.include "vol_envelopes.i"\n'

        includes.forEach(function (inc) {
          songsOut += inc
        })

        fs.appendFile(soundEnginePath, songsOut, function (err) {
          if (err) {
            console.error(err)
          }
        })
      }
    })

  } else {
    console.error(err)
  }
}

Song.prototype.write = function write () {
  mkdirp(buildDir, buildSongs)
}

module.exports = Song