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

generate qrcode,support svg base64 utf8

import Buffer from '../utils/buffer';

/**
 * Helper class to handle QR Code symbol modules
 *
 * @param {Number} size Symbol size
 */
function BitMatrix(size) {
  if (!size || size < 1) {
    throw new Error('BitMatrix size must be defined and greater than 0');
  }

  this.size = size;
  this.data = new Buffer(size * size);
  this.data.fill(0);
  this.reservedBit = new Buffer(size * size);
  this.reservedBit.fill(0);
}

/**
 * Set bit value at specified location
 * If reserved flag is set, this bit will be ignored during masking process
 *
 * @param {Number}  row
 * @param {Number}  col
 * @param {Boolean} value
 * @param {Boolean} reserved
 */
BitMatrix.prototype.set = function(row, col, value, reserved) {
  const index = row * this.size + col;
  this.data[index] = value;
  if (reserved) this.reservedBit[index] = true;
};

/**
 * Returns bit value at specified location
 *
 * @param  {Number}  row
 * @param  {Number}  col
 * @return {Boolean}
 */
BitMatrix.prototype.get = function(row, col) {
  return this.data[row * this.size + col];
};

/**
 * Applies xor operator at specified location
 * (used during masking process)
 *
 * @param {Number}  row
 * @param {Number}  col
 * @param {Boolean} value
 */
BitMatrix.prototype.xor = function(row, col, value) {
  this.data[row * this.size + col] ^= value;
};

/**
 * Check if bit at specified location is reserved
 *
 * @param {Number}   row
 * @param {Number}   col
 * @return {Boolean}
 */
BitMatrix.prototype.isReserved = function(row, col) {
  return this.reservedBit[row * this.size + col];
};

export default BitMatrix;