/*
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Ported to JavaScript by Lazar Laszlo 2011
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lazarsoft@gmail.com, www.lazarsoft.info
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*/
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/*
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*
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* Copyright 2007 ZXing authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import FormatInformation from './formatinf';
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import Version from './version';
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import DataMask from './datamask';
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export default function BitMatrixParser(bitMatrix) {
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var dimension = bitMatrix.Dimension;
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if (dimension < 21 || (dimension & 0x03) != 1) {
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throw "Error BitMatrixParser";
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}
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this.bitMatrix = bitMatrix;
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this.parsedVersion = null;
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this.parsedFormatInfo = null;
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}
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BitMatrixParser.prototype.copyBit = function(i, j, versionBits) {
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return this.bitMatrix.get_Renamed(i, j) ? (versionBits << 1) | 0x1 : versionBits << 1;
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};
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BitMatrixParser.prototype.readFormatInformation = function() {
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if (this.parsedFormatInfo != null) {
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return this.parsedFormatInfo;
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}
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// Read top-left format info bits
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var formatInfoBits = 0;
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for (var i = 0; i < 6; i++) {
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formatInfoBits = this.copyBit(i, 8, formatInfoBits);
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}
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// .. and skip a bit in the timing pattern ...
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formatInfoBits = this.copyBit(7, 8, formatInfoBits);
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formatInfoBits = this.copyBit(8, 8, formatInfoBits);
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formatInfoBits = this.copyBit(8, 7, formatInfoBits);
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// .. and skip a bit in the timing pattern ...
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for (var j = 5; j >= 0; j--) {
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formatInfoBits = this.copyBit(8, j, formatInfoBits);
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}
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this.parsedFormatInfo = FormatInformation.decodeFormatInformation(formatInfoBits);
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if (this.parsedFormatInfo != null) {
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return this.parsedFormatInfo;
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}
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// Hmm, failed. Try the top-right/bottom-left pattern
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var dimension = this.bitMatrix.Dimension;
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formatInfoBits = 0;
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var iMin = dimension - 8;
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for (var i = dimension - 1; i >= iMin; i--) {
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formatInfoBits = this.copyBit(i, 8, formatInfoBits);
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}
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for (var j = dimension - 7; j < dimension; j++) {
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formatInfoBits = this.copyBit(8, j, formatInfoBits);
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}
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this.parsedFormatInfo = FormatInformation.decodeFormatInformation(formatInfoBits);
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if (this.parsedFormatInfo != null) {
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return this.parsedFormatInfo;
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}
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throw "Error readFormatInformation";
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};
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BitMatrixParser.prototype.readVersion = function() {
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if (this.parsedVersion != null) {
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return this.parsedVersion;
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}
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var dimension = this.bitMatrix.Dimension;
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var provisionalVersion = (dimension - 17) >> 2;
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if (provisionalVersion <= 6) {
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return Version.getVersionForNumber(provisionalVersion);
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}
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// Read top-right version info: 3 wide by 6 tall
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var versionBits = 0;
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var ijMin = dimension - 11;
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for (var j = 5; j >= 0; j--) {
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for (var i = dimension - 9; i >= ijMin; i--) {
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versionBits = this.copyBit(i, j, versionBits);
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}
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}
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this.parsedVersion = Version.decodeVersionInformation(versionBits);
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if (this.parsedVersion != null && this.parsedVersion.DimensionForVersion == dimension) {
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return this.parsedVersion;
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}
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// Hmm, failed. Try bottom left: 6 wide by 3 tall
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versionBits = 0;
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for (var i = 5; i >= 0; i--) {
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for (var j = dimension - 9; j >= ijMin; j--) {
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versionBits = this.copyBit(i, j, versionBits);
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}
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}
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this.parsedVersion = Version.decodeVersionInformation(versionBits);
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if (this.parsedVersion != null && this.parsedVersion.DimensionForVersion == dimension) {
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return this.parsedVersion;
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}
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throw "Error readVersion";
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};
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BitMatrixParser.prototype.readCodewords = function() {
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var formatInfo = this.readFormatInformation();
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var version = this.readVersion();
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// Get the data mask for the format used in this QR Code. This will exclude
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// some bits from reading as we wind through the bit matrix.
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var dataMask = DataMask.forReference(formatInfo.dataMask);
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var dimension = this.bitMatrix.Dimension;
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dataMask.unmaskBitMatrix(this.bitMatrix, dimension);
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var functionPattern = version.buildFunctionPattern();
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var readingUp = true;
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var result = new Array(version.totalCodewords);
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var resultOffset = 0;
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var currentByte = 0;
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var bitsRead = 0;
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// Read columns in pairs, from right to left
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for (var j = dimension - 1; j > 0; j -= 2) {
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if (j == 6) {
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// Skip whole column with vertical alignment pattern;
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// saves time and makes the other code proceed more cleanly
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j--;
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}
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// Read alternatingly from bottom to top then top to bottom
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for (var count = 0; count < dimension; count++) {
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var i = readingUp ? dimension - 1 - count : count;
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for (var col = 0; col < 2; col++) {
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// Ignore bits covered by the function pattern
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if (!functionPattern.get_Renamed(j - col, i)) {
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// Read a bit
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bitsRead++;
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currentByte <<= 1;
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if (this.bitMatrix.get_Renamed(j - col, i)) {
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currentByte |= 1;
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}
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// If we've made a whole byte, save it off
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if (bitsRead == 8) {
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result[resultOffset++] = currentByte;
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bitsRead = 0;
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currentByte = 0;
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}
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}
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}
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}
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readingUp ^= true; // readingUp = !readingUp; // switch directions
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}
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if (resultOffset != version.totalCodewords) {
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throw "Error readCodewords";
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}
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return result;
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};
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