bitcoin-atm

bmparser.js

(5780B)

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