text: /*
    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.
  */
  
  
  var MIN_SKIP = 3;
  var MAX_MODULES = 57;
  var INTEGER_MATH_SHIFT = 8;
  var CENTER_QUORUM = 2;
  
  qrcode.orderBestPatterns=function(patterns)
  		{
  			
  			function distance( pattern1,  pattern2)
  			{
  				xDiff = pattern1.X - pattern2.X;
  				yDiff = pattern1.Y - pattern2.Y;
  				return  Math.sqrt( (xDiff * xDiff + yDiff * yDiff));
  			}
  			
  			/// <summary> Returns the z component of the cross product between vectors BC and BA.</summary>
  			function crossProductZ( pointA,  pointB,  pointC)
  			{
  				var bX = pointB.x;
  				var bY = pointB.y;
  				return ((pointC.x - bX) * (pointA.y - bY)) - ((pointC.y - bY) * (pointA.x - bX));
  			}
  
  			
  			// Find distances between pattern centers
  			var zeroOneDistance = distance(patterns[0], patterns[1]);
  			var oneTwoDistance = distance(patterns[1], patterns[2]);
  			var zeroTwoDistance = distance(patterns[0], patterns[2]);
  			
  			var pointA, pointB, pointC;
  			// Assume one closest to other two is B; A and C will just be guesses at first
  			if (oneTwoDistance >= zeroOneDistance && oneTwoDistance >= zeroTwoDistance)
  			{
  				pointB = patterns[0];
  				pointA = patterns[1];
  				pointC = patterns[2];
  			}
  			else if (zeroTwoDistance >= oneTwoDistance && zeroTwoDistance >= zeroOneDistance)
  			{
  				pointB = patterns[1];
  				pointA = patterns[0];
  				pointC = patterns[2];
  			}
  			else
  			{
  				pointB = patterns[2];
  				pointA = patterns[0];
  				pointC = patterns[1];
  			}
  			
  			// Use cross product to figure out whether A and C are correct or flipped.
  			// This asks whether BC x BA has a positive z component, which is the arrangement
  			// we want for A, B, C. If it's negative, then we've got it flipped around and
  			// should swap A and C.
  			if (crossProductZ(pointA, pointB, pointC) < 0.0)
  			{
  				var temp = pointA;
  				pointA = pointC;
  				pointC = temp;
  			}
  			
  			patterns[0] = pointA;
  			patterns[1] = pointB;
  			patterns[2] = pointC;
  		}
  
  
  function FinderPattern(posX, posY,  estimatedModuleSize)
  {
  	this.x=posX;
  	this.y=posY;
  	this.count = 1;
  	this.estimatedModuleSize = estimatedModuleSize;
  	
  	this.__defineGetter__("EstimatedModuleSize", function()
  	{
  		return this.estimatedModuleSize;
  	}); 
  	this.__defineGetter__("Count", function()
  	{
  		return this.count;
  	});
  	this.__defineGetter__("X", function()
  	{
  		return this.x;
  	});
  	this.__defineGetter__("Y", function()
  	{
  		return this.y;
  	});
  	this.incrementCount = function()
  	{
  		this.count++;
  	}
  	this.aboutEquals=function( moduleSize,  i,  j)
  		{
  			if (Math.abs(i - this.y) <= moduleSize && Math.abs(j - this.x) <= moduleSize)
  			{
  				var moduleSizeDiff = Math.abs(moduleSize - this.estimatedModuleSize);
  				return moduleSizeDiff <= 1.0 || moduleSizeDiff / this.estimatedModuleSize <= 1.0;
  			}
  			return false;
  		}
  	
  }
  
  function FinderPatternInfo(patternCenters)
  {
  	this.bottomLeft = patternCenters[0];
  	this.topLeft = patternCenters[1];
  	this.topRight = patternCenters[2];
  	this.__defineGetter__("BottomLeft", function()
  	{
  		return this.bottomLeft;
  	}); 
  	this.__defineGetter__("TopLeft", function()
  	{
  		return this.topLeft;
  	}); 
  	this.__defineGetter__("TopRight", function()
  	{
  		return this.topRight;
  	}); 
  }
  
  function FinderPatternFinder()
  {
  	this.image=null;
  	this.possibleCenters = [];
  	this.hasSkipped = false;
  	this.crossCheckStateCount = new Array(0,0,0,0,0);
  	this.resultPointCallback = null;
  	
  	this.__defineGetter__("CrossCheckStateCount", function()
  	{
  		this.crossCheckStateCount[0] = 0;
  		this.crossCheckStateCount[1] = 0;
  		this.crossCheckStateCount[2] = 0;
  		this.crossCheckStateCount[3] = 0;
  		this.crossCheckStateCount[4] = 0;
  		return this.crossCheckStateCount;
  	}); 
  	
  	this.foundPatternCross=function( stateCount)
  		{
  			var totalModuleSize = 0;
  			for (var i = 0; i < 5; i++)
  			{
  				var count = stateCount[i];
  				if (count == 0)
  				{
  					return false;
  				}
  				totalModuleSize += count;
  			}
  			if (totalModuleSize < 7)
  			{
  				return false;
  			}
  			var moduleSize = Math.floor((totalModuleSize << INTEGER_MATH_SHIFT) / 7);
  			var maxVariance = Math.floor(moduleSize / 2);
  			// Allow less than 50% variance from 1-1-3-1-1 proportions
  			return Math.abs(moduleSize - (stateCount[0] << INTEGER_MATH_SHIFT)) < maxVariance && Math.abs(moduleSize - (stateCount[1] << INTEGER_MATH_SHIFT)) < maxVariance && Math.abs(3 * moduleSize - (stateCount[2] << INTEGER_MATH_SHIFT)) < 3 * maxVariance && Math.abs(moduleSize - (stateCount[3] << INTEGER_MATH_SHIFT)) < maxVariance && Math.abs(moduleSize - (stateCount[4] << INTEGER_MATH_SHIFT)) < maxVariance;
  		}
  	this.centerFromEnd=function( stateCount,  end)
  		{
  			return  (end - stateCount[4] - stateCount[3]) - stateCount[2] / 2.0;
  		}
  	this.crossCheckVertical=function( startI,  centerJ,  maxCount,  originalStateCountTotal)
  		{
  			var image = this.image;
  			
  			var maxI = qrcode.height;
  			var stateCount = this.CrossCheckStateCount;
  			
  			// Start counting up from center
  			var i = startI;
  			while (i >= 0 && image[centerJ + i*qrcode.width])
  			{
  				stateCount[2]++;
  				i--;
  			}
  			if (i < 0)
  			{
  				return NaN;
  			}
  			while (i >= 0 && !image[centerJ +i*qrcode.width] && stateCount[1] <= maxCount)
  			{
  				stateCount[1]++;
  				i--;
  			}
  			// If already too many modules in this state or ran off the edge:
  			if (i < 0 || stateCount[1] > maxCount)
  			{
  				return NaN;
  			}
  			while (i >= 0 && image[centerJ + i*qrcode.width] && stateCount[0] <= maxCount)
  			{
  				stateCount[0]++;
  				i--;
  			}
  			if (stateCount[0] > maxCount)
  			{
  				return NaN;
  			}
  			
  			// Now also count down from center
  			i = startI + 1;
  			while (i < maxI && image[centerJ +i*qrcode.width])
  			{
  				stateCount[2]++;
  				i++;
  			}
  			if (i == maxI)
  			{
  				return NaN;
  			}
  			while (i < maxI && !image[centerJ + i*qrcode.width] && stateCount[3] < maxCount)
  			{
  				stateCount[3]++;
  				i++;
  			}
  			if (i == maxI || stateCount[3] >= maxCount)
  			{
  				return NaN;
  			}
  			while (i < maxI && image[centerJ + i*qrcode.width] && stateCount[4] < maxCount)
  			{
  				stateCount[4]++;
  				i++;
  			}
  			if (stateCount[4] >= maxCount)
  			{
  				return NaN;
  			}
  			
  			// If we found a finder-pattern-like section, but its size is more than 40% different than
  			// the original, assume it's a false positive
  			var stateCountTotal = stateCount[0] + stateCount[1] + stateCount[2] + stateCount[3] + stateCount[4];
  			if (5 * Math.abs(stateCountTotal - originalStateCountTotal) >= 2 * originalStateCountTotal)
  			{
  				return NaN;
  			}
  			
  			return this.foundPatternCross(stateCount)?this.centerFromEnd(stateCount, i):NaN;
  		}
  	this.crossCheckHorizontal=function( startJ,  centerI,  maxCount, originalStateCountTotal)
  		{
  			var image = this.image;
  			
  			var maxJ = qrcode.width;
  			var stateCount = this.CrossCheckStateCount;
  			
  			var j = startJ;
  			while (j >= 0 && image[j+ centerI*qrcode.width])
  			{
  				stateCount[2]++;
  				j--;
  			}
  			if (j < 0)
  			{
  				return NaN;
  			}
  			while (j >= 0 && !image[j+ centerI*qrcode.width] && stateCount[1] <= maxCount)
  			{
  				stateCount[1]++;
  				j--;
  			}
  			if (j < 0 || stateCount[1] > maxCount)
  			{
  				return NaN;
  			}
  			while (j >= 0 && image[j+ centerI*qrcode.width] && stateCount[0] <= maxCount)
  			{
  				stateCount[0]++;
  				j--;
  			}
  			if (stateCount[0] > maxCount)
  			{
  				return NaN;
  			}
  			
  			j = startJ + 1;
  			while (j < maxJ && image[j+ centerI*qrcode.width])
  			{
  				stateCount[2]++;
  				j++;
  			}
  			if (j == maxJ)
  			{
  				return NaN;
  			}
  			while (j < maxJ && !image[j+ centerI*qrcode.width] && stateCount[3] < maxCount)
  			{
  				stateCount[3]++;
  				j++;
  			}
  			if (j == maxJ || stateCount[3] >= maxCount)
  			{
  				return NaN;
  			}
  			while (j < maxJ && image[j+ centerI*qrcode.width] && stateCount[4] < maxCount)
  			{
  				stateCount[4]++;
  				j++;
  			}
  			if (stateCount[4] >= maxCount)
  			{
  				return NaN;
  			}
  			
  			// If we found a finder-pattern-like section, but its size is significantly different than
  			// the original, assume it's a false positive
  			var stateCountTotal = stateCount[0] + stateCount[1] + stateCount[2] + stateCount[3] + stateCount[4];
  			if (5 * Math.abs(stateCountTotal - originalStateCountTotal) >= originalStateCountTotal)
  			{
  				return NaN;
  			}
  			
  			return this.foundPatternCross(stateCount)?this.centerFromEnd(stateCount, j):NaN;
  		}
  	this.handlePossibleCenter=function( stateCount,  i,  j)
  		{
  			var stateCountTotal = stateCount[0] + stateCount[1] + stateCount[2] + stateCount[3] + stateCount[4];
  			var centerJ = this.centerFromEnd(stateCount, j); //float
  			var centerI = this.crossCheckVertical(i, Math.floor( centerJ), stateCount[2], stateCountTotal); //float
  			if (!isNaN(centerI))
  			{
  				// Re-cross check
  				centerJ = this.crossCheckHorizontal(Math.floor( centerJ), Math.floor( centerI), stateCount[2], stateCountTotal);
  				if (!isNaN(centerJ))
  				{
  					var estimatedModuleSize =   stateCountTotal / 7.0;
  					var found = false;
  					var max = this.possibleCenters.length;
  					for (var index = 0; index < max; index++)
  					{
  						var center = this.possibleCenters[index];
  						// Look for about the same center and module size:
  						if (center.aboutEquals(estimatedModuleSize, centerI, centerJ))
  						{
  							center.incrementCount();
  							found = true;
  							break;
  						}
  					}
  					if (!found)
  					{
  						var point = new FinderPattern(centerJ, centerI, estimatedModuleSize);
  						this.possibleCenters.push(point);
  						if (this.resultPointCallback != null)
  						{
  							this.resultPointCallback.foundPossibleResultPoint(point);
  						}
  					}
  					return true;
  				}
  			}
  			return false;
  		}
  		
  	this.selectBestPatterns=function()
  		{
  			
  			var startSize = this.possibleCenters.length;
  			if (startSize < 3)
  			{
  				// Couldn't find enough finder patterns
  				throw "Couldn't find enough finder patterns";
  			}
  			
  			// Filter outlier possibilities whose module size is too different
  			if (startSize > 3)
  			{
  				// But we can only afford to do so if we have at least 4 possibilities to choose from
  				var totalModuleSize = 0.0;
  				for (var i = 0; i < startSize; i++)
  				{
  					totalModuleSize +=  this.possibleCenters[i].EstimatedModuleSize;
  				}
  				var average = totalModuleSize /  startSize;
  				for (var i = 0; i < this.possibleCenters.length && this.possibleCenters.length > 3; i++)
  				{
  					var pattern =  this.possibleCenters[i];
  					if (Math.abs(pattern.EstimatedModuleSize - average) > 0.2 * average)
  					{
  						this.possibleCenters.remove(i);
  						i--;
  					}
  				}
  			}
  			
  			if (this.possibleCenters.length > 3)
  			{
  				// Throw away all but those first size candidate points we found.
  				this.possibleCenters.sort(function(a, b){
  					if (a.count > b.count){return -1;}
  					if (a.count < b.count){return 1;}
  					return 0;
  				});
  			}
  			
  			return new Array( this.possibleCenters[0],  this.possibleCenters[1],  this.possibleCenters[2]);
  		}
  		
  	this.findRowSkip=function()
  		{
  			var max = this.possibleCenters.length;
  			if (max <= 1)
  			{
  				return 0;
  			}
  			var firstConfirmedCenter = null;
  			for (var i = 0; i < max; i++)
  			{
  				var center =  this.possibleCenters[i];
  				if (center.Count >= CENTER_QUORUM)
  				{
  					if (firstConfirmedCenter == null)
  					{
  						firstConfirmedCenter = center;
  					}
  					else
  					{
  						// We have two confirmed centers
  						// How far down can we skip before resuming looking for the next
  						// pattern? In the worst case, only the difference between the
  						// difference in the x / y coordinates of the two centers.
  						// This is the case where you find top left last.
  						this.hasSkipped = true;
  						return Math.floor ((Math.abs(firstConfirmedCenter.X - center.X) - Math.abs(firstConfirmedCenter.Y - center.Y)) / 2);
  					}
  				}
  			}
  			return 0;
  		}
  	
  	this.haveMultiplyConfirmedCenters=function()
  		{
  			var confirmedCount = 0;
  			var totalModuleSize = 0.0;
  			var max = this.possibleCenters.length;
  			for (var i = 0; i < max; i++)
  			{
  				var pattern =  this.possibleCenters[i];
  				if (pattern.Count >= CENTER_QUORUM)
  				{
  					confirmedCount++;
  					totalModuleSize += pattern.EstimatedModuleSize;
  				}
  			}
  			if (confirmedCount < 3)
  			{
  				return false;
  			}
  			// OK, we have at least 3 confirmed centers, but, it's possible that one is a "false positive"
  			// and that we need to keep looking. We detect this by asking if the estimated module sizes
  			// vary too much. We arbitrarily say that when the total deviation from average exceeds
  			// 5% of the total module size estimates, it's too much.
  			var average = totalModuleSize / max;
  			var totalDeviation = 0.0;
  			for (var i = 0; i < max; i++)
  			{
  				pattern = this.possibleCenters[i];
  				totalDeviation += Math.abs(pattern.EstimatedModuleSize - average);
  			}
  			return totalDeviation <= 0.05 * totalModuleSize;
  		}
  		
  	this.findFinderPattern = function(image){
  		var tryHarder = false;
  		this.image=image;
  		var maxI = qrcode.height;
  		var maxJ = qrcode.width;
  		var iSkip = Math.floor((3 * maxI) / (4 * MAX_MODULES));
  		if (iSkip < MIN_SKIP || tryHarder)
  		{
  				iSkip = MIN_SKIP;
  		}
  		
  		var done = false;
  		var stateCount = new Array(5);
  		for (var i = iSkip - 1; i < maxI && !done; i += iSkip)
  		{
  			// Get a row of black/white values
  			stateCount[0] = 0;
  			stateCount[1] = 0;
  			stateCount[2] = 0;
  			stateCount[3] = 0;
  			stateCount[4] = 0;
  			var currentState = 0;
  			for (var j = 0; j < maxJ; j++)
  			{
  				if (image[j+i*qrcode.width] )
  				{
  					// Black pixel
  					if ((currentState & 1) == 1)
  					{
  						// Counting white pixels
  						currentState++;
  					}
  					stateCount[currentState]++;
  				}
  				else
  				{
  					// White pixel
  					if ((currentState & 1) == 0)
  					{
  						// Counting black pixels
  						if (currentState == 4)
  						{
  							// A winner?
  							if (this.foundPatternCross(stateCount))
  							{
  								// Yes
  								var confirmed = this.handlePossibleCenter(stateCount, i, j);
  								if (confirmed)
  								{
  									// Start examining every other line. Checking each line turned out to be too
  									// expensive and didn't improve performance.
  									iSkip = 2;
  									if (this.hasSkipped)
  									{
  										done = this.haveMultiplyConfirmedCenters();
  									}
  									else
  									{
  										var rowSkip = this.findRowSkip();
  										if (rowSkip > stateCount[2])
  										{
  											// Skip rows between row of lower confirmed center
  											// and top of presumed third confirmed center
  											// but back up a bit to get a full chance of detecting
  											// it, entire width of center of finder pattern
  											
  											// Skip by rowSkip, but back off by stateCount[2] (size of last center
  											// of pattern we saw) to be conservative, and also back off by iSkip which
  											// is about to be re-added
  											i += rowSkip - stateCount[2] - iSkip;
  											j = maxJ - 1;
  										}
  									}
  								}
  								else
  								{
  									// Advance to next black pixel
  									do 
  									{
  										j++;
  									}
  									while (j < maxJ && !image[j + i*qrcode.width]);
  									j--; // back up to that last white pixel
  								}
  								// Clear state to start looking again
  								currentState = 0;
  								stateCount[0] = 0;
  								stateCount[1] = 0;
  								stateCount[2] = 0;
  								stateCount[3] = 0;
  								stateCount[4] = 0;
  							}
  							else
  							{
  								// No, shift counts back by two
  								stateCount[0] = stateCount[2];
  								stateCount[1] = stateCount[3];
  								stateCount[2] = stateCount[4];
  								stateCount[3] = 1;
  								stateCount[4] = 0;
  								currentState = 3;
  							}
  						}
  						else
  						{
  							stateCount[++currentState]++;
  						}
  					}
  					else
  					{
  						// Counting white pixels
  						stateCount[currentState]++;
  					}
  				}
  			}
  			if (this.foundPatternCross(stateCount))
  			{
  				var confirmed = this.handlePossibleCenter(stateCount, i, maxJ);
  				if (confirmed)
  				{
  					iSkip = stateCount[0];
  					if (this.hasSkipped)
  					{
  						// Found a third one
  						done = haveMultiplyConfirmedCenters();
  					}
  				}
  			}
  		}
  		
  		var patternInfo = this.selectBestPatterns();
  		qrcode.orderBestPatterns(patternInfo);
  		
  		return new FinderPatternInfo(patternInfo);
  	};
  }