LightingSystemApp-serial/.svn/pristine/3b/3b4cba54317fff6b46c20060747a59df0e377287.svn-base

/*
  Ported to JavaScript by Lazar Laszlo 2011

  lazarsoft@gmail.com, www.lazarsoft.info

*/

/*
*
* Copyright 2007 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

import FormatInformation from './formatinf';
import Version from './version';
import DataMask from './datamask';

export default function BitMatrixParser(bitMatrix) {
  var dimension = bitMatrix.Dimension;
  if (dimension < 21 || (dimension & 0x03) != 1) {
    throw "Error BitMatrixParser";
  }
  this.bitMatrix = bitMatrix;
  this.parsedVersion = null;
  this.parsedFormatInfo = null;
}

BitMatrixParser.prototype.copyBit = function(i,  j,  versionBits) {
  return this.bitMatrix.get_Renamed(i, j) ? (versionBits << 1) | 0x1 : versionBits << 1;
};

BitMatrixParser.prototype.readFormatInformation = function() {
  if (this.parsedFormatInfo != null) {
    return this.parsedFormatInfo;
  }

  // Read top-left format info bits
  var formatInfoBits = 0;
  for (var i = 0; i < 6; i++) {
    formatInfoBits = this.copyBit(i, 8, formatInfoBits);
  }
  // .. and skip a bit in the timing pattern ...
  formatInfoBits = this.copyBit(7, 8, formatInfoBits);
  formatInfoBits = this.copyBit(8, 8, formatInfoBits);
  formatInfoBits = this.copyBit(8, 7, formatInfoBits);
  // .. and skip a bit in the timing pattern ...
  for (var j = 5; j >= 0; j--) {
    formatInfoBits = this.copyBit(8, j, formatInfoBits);
  }

  this.parsedFormatInfo = FormatInformation.decodeFormatInformation(formatInfoBits);
  if (this.parsedFormatInfo != null) {
    return this.parsedFormatInfo;
  }

  // Hmm, failed. Try the top-right/bottom-left pattern
  var dimension = this.bitMatrix.Dimension;
  formatInfoBits = 0;
  var iMin = dimension - 8;
  for (var i = dimension - 1; i >= iMin; i--) {
    formatInfoBits = this.copyBit(i, 8, formatInfoBits);
  }
  for (var j = dimension - 7; j < dimension; j++) {
    formatInfoBits = this.copyBit(8, j, formatInfoBits);
  }

  this.parsedFormatInfo = FormatInformation.decodeFormatInformation(formatInfoBits);
  if (this.parsedFormatInfo != null) {
    return this.parsedFormatInfo;
  }
  throw "Error readFormatInformation";
};

BitMatrixParser.prototype.readVersion = function() {
  if (this.parsedVersion != null) {
    return this.parsedVersion;
  }

  var dimension = this.bitMatrix.Dimension;

  var provisionalVersion = (dimension - 17) >> 2;
  if (provisionalVersion <= 6) {
    return Version.getVersionForNumber(provisionalVersion);
  }

  // Read top-right version info: 3 wide by 6 tall
  var versionBits = 0;
  var ijMin = dimension - 11;
  for (var j = 5; j >= 0; j--) {
    for (var i = dimension - 9; i >= ijMin; i--) {
      versionBits = this.copyBit(i, j, versionBits);
    }
  }

  this.parsedVersion = Version.decodeVersionInformation(versionBits);
  if (this.parsedVersion != null && this.parsedVersion.DimensionForVersion == dimension) {
    return this.parsedVersion;
  }

  // Hmm, failed. Try bottom left: 6 wide by 3 tall
  versionBits = 0;
  for (var i = 5; i >= 0; i--) {
    for (var j = dimension - 9; j >= ijMin; j--) {
      versionBits = this.copyBit(i, j, versionBits);
    }
  }

  this.parsedVersion = Version.decodeVersionInformation(versionBits);
  if (this.parsedVersion != null && this.parsedVersion.DimensionForVersion == dimension) {
    return this.parsedVersion;
  }
  throw "Error readVersion";
};

BitMatrixParser.prototype.readCodewords = function() {
  var formatInfo = this.readFormatInformation();
  var version = this.readVersion();

  // Get the data mask for the format used in this QR Code. This will exclude
  // some bits from reading as we wind through the bit matrix.
  var dataMask = DataMask.forReference(formatInfo.dataMask);
  var dimension = this.bitMatrix.Dimension;
  dataMask.unmaskBitMatrix(this.bitMatrix, dimension);

  var functionPattern = version.buildFunctionPattern();

  var readingUp = true;
  var result = new Array(version.totalCodewords);
  var resultOffset = 0;
  var currentByte = 0;
  var bitsRead = 0;
  // Read columns in pairs, from right to left
  for (var j = dimension - 1; j > 0; j -= 2) {
    if (j == 6) {
      // Skip whole column with vertical alignment pattern;
      // saves time and makes the other code proceed more cleanly
      j--;
    }
    // Read alternatingly from bottom to top then top to bottom
    for (var count = 0; count < dimension; count++) {
      var i = readingUp ? dimension - 1 - count : count;
      for (var col = 0; col < 2; col++) {
        // Ignore bits covered by the function pattern
        if (!functionPattern.get_Renamed(j - col, i)) {
          // Read a bit
          bitsRead++;
          currentByte <<= 1;
          if (this.bitMatrix.get_Renamed(j - col, i)) {
            currentByte |= 1;
          }
          // If we've made a whole byte, save it off
          if (bitsRead == 8) {
            result[resultOffset++] =  currentByte;
            bitsRead = 0;
            currentByte = 0;
          }
        }
      }
    }
    readingUp ^= true; // readingUp = !readingUp; // switch directions
  }
  if (resultOffset != version.totalCodewords) {
    throw "Error readCodewords";
  }
  return result;
};