package
{
	import flash.display.Bitmap;
	import flash.display.BitmapData;
	import flash.utils.ByteArray;
	
	public class LabelMap
	{
		private var imageData:BitmapData; //was imageData
		private var labelMap:Array=new Array; //same size as image, 0=background, other=label, adress as labelMap[y][x]				
		private var inBytes:ByteArray;	//note bytes organised A,R,G,B; A,R,G,B etc.
		//arrays to store Bounding Box info (e.g. bbl[4]= left side of bounding box for region 4) 
		public static const MAXLABELS:int=10000;
		public var bbl:Array=new Array; 
		public var bbr:Array=new Array; 
		public var bbt:Array=new Array; 
		public var bbb:Array=new Array; 
		public var labelUsed:Array=new Array;
	
		public function LabelMap()
		{
		}
		
		public function loadBitmap(bm:Bitmap):void{
			imageData=bm.bitmapData;
			inBytes = imageData.getPixels(imageData.rect);	
		}
		
		public function performLabeling():void{
			//breaks image up into regions, labels them and caculated the bounding boxes
			var w:int=imageData.width; var w4:int=w*4;
			var h:int=imageData.height;
			var i:int=0; var i4:int=0;
			var nPix:int=h*w;
			for (i=0; i<h; i++){
				var row:Array=new Array; 
				for (var j:int=0; j<w; j++) row.push(int(0));
				labelMap.push(row);
			} 
			var currentLabel:int=0;
			var connectedComponents:Array=new Array
			var x:int=0; var y:int=0;
			
			//Now scan image ignoring 1 pixel wide border
			i=w+1; i4=4*i; //start @ 2nd pixel, 2nd line
			for (y=1; y<h-1; y++){
				//debug.text+="\n"+y.toString()+": ";
				for (x=1; x<w-1; x++, i++, i4+=4){
					var red:int=inBytes[i4+1]; var green:int=inBytes[i4+2]; var blue:int=inBytes[i4+3];
					if(red>150 && green>200 && blue>150) labelMap[y][x]=0;	//have background
					else 
					{ //have found a sticky so check for previous labels
						if      (labelMap[y][x-1]>0)   labelMap[y][x]=labelMap[y][x-1];   //check middle left
						else if (labelMap[y-1][x-1]>0) labelMap[y][x]=labelMap[y-1][x-1]; //check top left
						else if (labelMap[y-1][x]>0)   labelMap[y][x]=labelMap[y-1][x];   //check top middle
						else if (labelMap[y-1][x+1]>0) labelMap[y][x]=labelMap[y-1][x+1]; //check top right 
						else    {currentLabel++; labelMap[y][x]=currentLabel; }           //new component
					}	
				}	
				i+=2; i4=4*i; //make i4 index skip last and first pixel of each line
			}
			//Printout labelMap
			//if(debugPrint) for (y=0; y<h; y++){debug.text+="\n"+y.toString()+": "; for (x=0; x<w; x++) debug.text+=labelMap[y][x].toString()+ ", "; } 
			
			//Set up arrays to store Bounding Box info (e.g. bbl[4]= left side of bounding box for region 4) 
			for (i=0; i<MAXLABELS; i++) {bbl[i]=w; bbr[i]=0; bbt[i]=h; bbb[i]=0; labelUsed[i]=false;}	
		
		 	//Reverse pass: relabel components that have multiple labels with unique labels and get bounding boxes
		 	for (y=h-2; y>=1; y--){
				for (x=w-2; x>=1; x--){ 
		 			if(labelMap[y][x]>0)
					{   //have found a sticky so sheck for multiple labels and adjust if necessary
						if      (labelMap[y+1][x]!=0)   labelMap[y][x]= labelMap[y+1][x];   //bottom middle
						else if (labelMap[y+1][x+1]!=0) labelMap[y][x]= labelMap[y+1][x+1]; //bottom rt
						else if (labelMap[y+1][x-1]!=0) labelMap[y][x]= labelMap[y+1][x-1]; //bottom left
						else if (labelMap[y][x+1]!=0)   labelMap[y][x]= labelMap[y][x+1];   //middle right
						var l:int=labelMap[y][x];
						
						//if (l>=MAXLABELS) Alert.show("MAXLABELS of: "+MAXLABELS+" exceeded", "ERROR");
						
						
						//Record region bounding box extremities
						//if(y*w+x!=i) Alert.show("index decrement wrong", "Error");
						if (x<bbl[l]) bbl[l]=x;
						if (x>bbr[l]) bbr[l]=x;
						if (y<bbt[l]) bbt[l]=y;
						if (y>bbb[l]) bbb[l]=y;
						labelUsed[l]=true;
					}  
				}		
			}				
		}
		
		public function printMap():String{
			var message:String, x:int, y:int;
			var w:int=imageData.width;
			var h:int=imageData.height;
			for (var i:int=1; i<MAXLABELS; i++) if (labelUsed[i]==true) {message+="\n\nLabel "+i+": bbl= "+bbl[i]+", bbr="+bbr[i]+", bbt= "+bbt[i]+", bbb= "+bbb[i];	}
 			//Printout labelMap
			for (y=0; y<h; y++){message+="\n"+y.toString()+": "; for (x=0; x<w; x++) message+=labelMap[y][x].toString()+ ", "; }
			return message;
		}
		
		public function drawBoundingBoxes():void{
		/* 	//Draw bounding boxes and display image
			for (i=1; i<maxLabels; i++) if (labelUsed[i]==true) drawBoundingBox(inBytes, h, w, bbl[i], bbt[i], bbr[i], bbb[i]);
			inBytes.position = 0;
			imageData.setPixels(imageData.rect, inBytes);
			var outBM:Bitmap = new Bitmap(imageData);
			outImg.source=outBM;
			//outImg.scaleX=outImg.scaleY=.50; 	
		*/
		}

		private function drawBoundingBox(img:ByteArray, h:int, w:int, bbl:int, bbt:int, bbr:int, bbb:int):void{
			var x:int, y:int; var w4:int=4*w;
			var i:int=4*bbl+w4*bbt; for (y=bbt; y<=bbb; y++, i+=w4) img[i+1]=img[i+2]=img[i+3]=0;
			i=4*bbr+w4*bbt; for (y=bbt; y<=bbb; y++, i+=w4) img[i+1]=img[i+2]=img[i+3]=0;
			i=4*bbl+w4*bbt; for (x=bbl; x<=bbr; x++, i+=4) img[i+1]=img[i+2]=img[i+3]=0;
			i=4*bbl+w4*bbb; for (x=bbl; x<=bbr; x++, i+=4) img[i+1]=img[i+2]=img[i+3]=0;	
		}
	}
}