SoundFontParameters.fromReader constructor

SoundFontParameters.fromReader(BinaryReader reader)

Implementation

factory SoundFontParameters.fromReader(BinaryReader reader) {
  String chunkId = reader.readFourCC();

  if (chunkId != "LIST") {
    throw "The LIST chunk was not found.";
  }

  int end = reader.readInt32();
  end += reader.pos;

  var listType = reader.readFourCC();

  if (listType != "pdta") {
    throw "The type of the LIST chunk must be 'pdta', but was '$listType'.";
  }

  List<PresetInfo> presetInfos = [];
  List<ZoneInfo> presetBag = [];
  List<Generator> presetGenerators = [];
  List<InstrumentInfo> instrumentInfos = [];
  List<ZoneInfo> instrumentBag = [];
  List<Generator> instrumentGenerators = [];
  List<SampleHeader> sampleHeaders = [];

  while (reader.pos < end) {
    String id = reader.readFourCC();
    int size = reader.readInt32();

    switch (id) {
      case "phdr":
        presetInfos = PresetInfo.readFromChunk(reader, size);
        break;
      case "pbag":
        presetBag = ZoneInfo.readFromChunk(reader, size);
        break;
      case "pmod":
        Modulator.discardData(reader, size);
        break;
      case "pgen":
        presetGenerators = Generator.readFromChunk(reader, size);
        break;
      case "inst":
        instrumentInfos = InstrumentInfo.readFromChunk(reader, size);
        break;
      case "ibag":
        instrumentBag = ZoneInfo.readFromChunk(reader, size);
        break;
      case "imod":
        Modulator.discardData(reader, size);
        break;
      case "igen":
        instrumentGenerators = Generator.readFromChunk(reader, size);
        break;
      case "shdr":
        sampleHeaders = SampleHeader.readFromChunk(reader, size);
        break;
      default:
        throw "The INFO list contains an unknown ID '$id'.";
    }
  }

  if (presetInfos.isEmpty) throw "The PHDR sub-chunk was not found.";
  if (presetBag.isEmpty) throw "The PBAG sub-chunk was not found.";
  if (presetGenerators.isEmpty) throw "The PGEN sub-chunk was not found.";
  if (instrumentInfos.isEmpty) throw "The INST sub-chunk was not found.";
  if (instrumentBag.isEmpty) throw "The IBAG sub-chunk was not found.";
  if (instrumentGenerators.isEmpty) throw "The IGEN sub-chunk was not found.";
  if (sampleHeaders.isEmpty) throw "The SHDR sub-chunk was not found.";

  List<Zone> instrumentZones = Zone.create(instrumentBag, instrumentGenerators);

  List<Instrument> instruments = Instrument.create(instrumentInfos, instrumentZones, sampleHeaders);

  List<Zone> presetZones = Zone.create(presetBag, presetGenerators);

  List<Preset> presets = Preset.create(presetInfos, presetZones, instruments);

  return SoundFontParameters(sampleHeaders: sampleHeaders, presets: presets, instruments: instruments);
}