Function getLZWRaster

src/qrcode.js:1885–1939

(lzwMinCodeSize)

    }

    var getLZWRaster = function (lzwMinCodeSize) {
      var clearCode = 1 << lzwMinCodeSize
      var endCode = (1 << lzwMinCodeSize) + 1
      var bitLength = lzwMinCodeSize + 1

      // Setup LZWTable
      var table = lzwTable()

      for (var i = 0; i < clearCode; i += 1) {
        table.add(String.fromCharCode(i))
      }
      table.add(String.fromCharCode(clearCode))
      table.add(String.fromCharCode(endCode))

      var byteOut = byteArrayOutputStream()
      var bitOut = bitOutputStream(byteOut)

      // clear code
      bitOut.write(clearCode, bitLength)

      var dataIndex = 0

      var s = String.fromCharCode(_data[dataIndex])
      dataIndex += 1

      while (dataIndex < _data.length) {
        var c = String.fromCharCode(_data[dataIndex])
        dataIndex += 1

        if (table.contains(s + c)) {
          s = s + c
        } else {
          bitOut.write(table.indexOf(s), bitLength)

          if (table.size() < 0xfff) {
            if (table.size() == (1 << bitLength)) {
              bitLength += 1
            }

            table.add(s + c)
          }

          s = c
        }
      }

      bitOut.write(table.indexOf(s), bitLength)

      // end code
      bitOut.write(endCode, bitLength)

      bitOut.flush()

      return byteOut.toByteArray()
    }

    var lzwTable = function () {
      var _map = {}