cnf-qrcode/src/lib/core/bit-buffer.js

generate qrcode,support svg base64 utf8

function BitBuffer() {
  this.buffer = [];
  this.length = 0;
}

BitBuffer.prototype = {

  get(index) {
    const bufIndex = Math.floor(index / 8);
    return ((this.buffer[bufIndex] >>> (7 - index % 8)) & 1) === 1;
  },

  put(num, length) {
    for (let i = 0; i < length; i++) {
      this.putBit(((num >>> (length - i - 1)) & 1) === 1);
    }
  },

  getLengthInBits() {
    return this.length;
  },

  putBit(bit) {
    const bufIndex = Math.floor(this.length / 8);
    if (this.buffer.length <= bufIndex) {
      this.buffer.push(0);
    }

    if (bit) {
      this.buffer[bufIndex] |= (0x80 >>> (this.length % 8));
    }

    this.length++;
  },
};

export default BitBuffer;