findpat.js

function FinderPattern(t,e,r){this.x=t,this.y=e,this.count=1,this.estimatedModuleSize=r,Object.defineProperties(this,{EstimatedModuleSize:{get:function(){return this.estimatedModuleSize}},Count:{get:function(){return this.count}},X:{get:function(){return this.x}},Y:{get:function(){return this.y}}}),this.incrementCount=function(){this.count++},this.aboutEquals=function(t,e,r){if(Math.abs(e-this.y)<=t&&Math.abs(r-this.x)<=t){var i=Math.abs(t-this.estimatedModuleSize);return 1>=i||i/this.estimatedModuleSize<=1}return!1}}function FinderPatternInfo(t){this.bottomLeft=t[0],this.topLeft=t[1],this.topRight=t[2],Object.defineProperties(this,{BottomLeft:{get:function(){return this.bottomLeft}},TopLeft:{get:function(){return this.topLeft}},TopRight:{get:function(){return this.topRight}}})}function FinderPatternFinder(){this.image=null,this.possibleCenters=[],this.hasSkipped=!1,this.crossCheckStateCount=new Array(0,0,0,0,0),this.resultPointCallback=null,Object.defineProperty(this,"CrossCheckStateCount",{get:function(){return this.crossCheckStateCount[0]=0,this.crossCheckStateCount[1]=0,this.crossCheckStateCount[2]=0,this.crossCheckStateCount[3]=0,this.crossCheckStateCount[4]=0,this.crossCheckStateCount}}),this.foundPatternCross=function(t){for(var e=0,r=0;5>r;r++){var i=t[r];if(0==i)return!1;e+=i}if(7>e)return!1;var s=Math.floor((e<<INTEGER_MATH_SHIFT)/7),n=Math.floor(s/2);return Math.abs(s-(t[0]<<INTEGER_MATH_SHIFT))<n&&Math.abs(s-(t[1]<<INTEGER_MATH_SHIFT))<n&&Math.abs(3*s-(t[2]<<INTEGER_MATH_SHIFT))<3*n&&Math.abs(s-(t[3]<<INTEGER_MATH_SHIFT))<n&&Math.abs(s-(t[4]<<INTEGER_MATH_SHIFT))<n},this.centerFromEnd=function(t,e){return e-t[4]-t[3]-t[2]/2},this.crossCheckVertical=function(t,e,r,i){for(var s=this.image,n=qrcode.height,o=this.CrossCheckStateCount,h=t;h>=0&&s[e+h*qrcode.width];)o[2]++,h--;if(0>h)return 0/0;for(;h>=0&&!s[e+h*qrcode.width]&&o[1]<=r;)o[1]++,h--;if(0>h||o[1]>r)return 0/0;for(;h>=0&&s[e+h*qrcode.width]&&o[0]<=r;)o[0]++,h--;if(o[0]>r)return 0/0;for(h=t+1;n>h&&s[e+h*qrcode.width];)o[2]++,h++;if(h==n)return 0/0;for(;n>h&&!s[e+h*qrcode.width]&&o[3]<r;)o[3]++,h++;if(h==n||o[3]>=r)return 0/0;for(;n>h&&s[e+h*qrcode.width]&&o[4]<r;)o[4]++,h++;if(o[4]>=r)return 0/0;var a=o[0]+o[1]+o[2]+o[3]+o[4];return 5*Math.abs(a-i)>=2*i?0/0:this.foundPatternCross(o)?this.centerFromEnd(o,h):0/0},this.crossCheckHorizontal=function(t,e,r,i){for(var s=this.image,n=qrcode.width,o=this.CrossCheckStateCount,h=t;h>=0&&s[h+e*qrcode.width];)o[2]++,h--;if(0>h)return 0/0;for(;h>=0&&!s[h+e*qrcode.width]&&o[1]<=r;)o[1]++,h--;if(0>h||o[1]>r)return 0/0;for(;h>=0&&s[h+e*qrcode.width]&&o[0]<=r;)o[0]++,h--;if(o[0]>r)return 0/0;for(h=t+1;n>h&&s[h+e*qrcode.width];)o[2]++,h++;if(h==n)return 0/0;for(;n>h&&!s[h+e*qrcode.width]&&o[3]<r;)o[3]++,h++;if(h==n||o[3]>=r)return 0/0;for(;n>h&&s[h+e*qrcode.width]&&o[4]<r;)o[4]++,h++;if(o[4]>=r)return 0/0;var a=o[0]+o[1]+o[2]+o[3]+o[4];return 5*Math.abs(a-i)>=i?0/0:this.foundPatternCross(o)?this.centerFromEnd(o,h):0/0},this.handlePossibleCenter=function(t,e,r){var i=t[0]+t[1]+t[2]+t[3]+t[4],s=this.centerFromEnd(t,r),n=this.crossCheckVertical(e,Math.floor(s),t[2],i);if(!isNaN(n)&&(s=this.crossCheckHorizontal(Math.floor(s),Math.floor(n),t[2],i),!isNaN(s))){for(var o=i/7,h=!1,a=this.possibleCenters.length,u=0;a>u;u++){var f=this.possibleCenters[u];if(f.aboutEquals(o,n,s)){f.incrementCount(),h=!0;break}}if(!h){var d=new FinderPattern(s,n,o);this.possibleCenters.push(d),null!=this.resultPointCallback&&this.resultPointCallback.foundPossibleResultPoint(d)}return!0}return!1},this.selectBestPatterns=function(){var t=this.possibleCenters.length;if(3>t)throw"Couldn't find enough finder patterns";if(t>3){for(var e=0,r=0,i=0;t>i;i++){var s=this.possibleCenters[i].EstimatedModuleSize;e+=s,r+=s*s}var n=e/t;this.possibleCenters.sort(function(t,e){var r=Math.abs(e.EstimatedModuleSize-n),i=Math.abs(t.EstimatedModuleSize-n);return i>r?-1:r==i?0:1});for(var o=Math.sqrt(r/t-n*n),h=Math.max(.2*n,o),i=0;i<this.possibleCenters.length&&this.possibleCenters.length>3;i++){var a=this.possibleCenters[i];Math.abs(a.EstimatedModuleSize-n)>h&&(this.possibleCenters.remove(i),i--)}}return this.possibleCenters.length>3&&this.possibleCenters.sort(function(t,e){return t.count>e.count?-1:t.count<e.count?1:0}),new Array(this.possibleCenters[0],this.possibleCenters[1],this.possibleCenters[2])},this.findRowSkip=function(){var t=this.possibleCenters.length;if(1>=t)return 0;for(var e=null,r=0;t>r;r++){var i=this.possibleCenters[r];if(i.Count>=CENTER_QUORUM){if(null!=e)return this.hasSkipped=!0,Math.floor((Math.abs(e.X-i.X)-Math.abs(e.Y-i.Y))/2);e=i}}return 0},this.haveMultiplyConfirmedCenters=function(){for(var t=0,e=0,r=this.possibleCenters.length,i=0;r>i;i++){var s=this.possibleCenters[i];s.Count>=CENTER_QUORUM&&(t++,e+=s.EstimatedModuleSize)}if(3>t)return!1;for(var n=e/r,o=0,i=0;r>i;i++)s=this.possibleCenters[i],o+=Math.abs(s.EstimatedModuleSize-n);return.05*e>=o},this.findFinderPattern=function(t){var e=!1;this.image=t;var r=qrcode.height,i=qrcode.width,s=Math.floor(3*r/(4*MAX_MODULES));(MIN_SKIP>s||e)&&(s=MIN_SKIP);for(var n=!1,o=new Array(5),h=s-1;r>h&&!n;h+=s){o[0]=0,o[1]=0,o[2]=0,o[3]=0,o[4]=0;for(var a=0,u=0;i>u;u++)if(t[u+h*qrcode.width])1==(1&a)&&a++,o[a]++;else if(0==(1&a))if(4==a)if(this.foundPatternCross(o)){var f=this.handlePossibleCenter(o,h,u);if(f)if(s=2,this.hasSkipped)n=this.haveMultiplyConfirmedCenters();else{var d=this.findRowSkip();d>o[2]&&(h+=d-o[2]-s,u=i-1)}else{do u++;while(i>u&&!t[u+h*qrcode.width]);u--}a=0,o[0]=0,o[1]=0,o[2]=0,o[3]=0,o[4]=0}else o[0]=o[2],o[1]=o[3],o[2]=o[4],o[3]=1,o[4]=0,a=3;else o[++a]++;else o[a]++;if(this.foundPatternCross(o)){var f=this.handlePossibleCenter(o,h,i);f&&(s=o[0],this.hasSkipped&&(n=haveMultiplyConfirmedCenters()))}}var c=this.selectBestPatterns();return qrcode.orderBestPatterns(c),new FinderPatternInfo(c)}}var MIN_SKIP=3,MAX_MODULES=57,INTEGER_MATH_SHIFT=8,CENTER_QUORUM=2;qrcode.orderBestPatterns=function(t){function e(t,e){return xDiff=t.X-e.X,yDiff=t.Y-e.Y,Math.sqrt(xDiff*xDiff+yDiff*yDiff)}function r(t,e,r){var i=e.x,s=e.y;return(r.x-i)*(t.y-s)-(r.y-s)*(t.x-i)}var i,s,n,o=e(t[0],t[1]),h=e(t[1],t[2]),a=e(t[0],t[2]);if(h>=o&&h>=a?(s=t[0],i=t[1],n=t[2]):a>=h&&a>=o?(s=t[1],i=t[0],n=t[2]):(s=t[2],i=t[0],n=t[1]),r(i,s,n)<0){var u=i;i=n,n=u}t[0]=i,t[1]=s,t[2]=n};