/*
	SIRDS will make a Single Image Stereogram 5/18/99 Chris Thiel 
	
*/

import java.awt.*;
import java.applet.Applet;
import java.io.*;
import java.net.*;



public class sirds extends Applet
{
	
	
	
	
	int colors[] = new int [256];
	
	int x, y, s, left, right;
	Color pix[]; // maximum x
	int same[];
	int Z[][];
	String Title;
	InputStream is = null;
	Image img;
	Graphics gr;
	
	// default parameters
	int dotColor = 0;
	boolean stereogram=true;
	String infile = null;
	int numRows;
	int numCols;
	int f = 1; 			// doubling factor
	int b = 0;			// number of border pixels
	
	int DPI=72; 		// resolution: dots per inch
	double mu = 1/3.0;  // distance  of viewer ratio 
	int E = (int)(Math.round(2.5*DPI));	
	
	public int separation (int Z) {
	//The farther the object Z=(-9..9),  the less the separation 
		return (int)(Math.round((1-mu*Z)*E/(2-mu*Z)));
	}
	public void readFile(String infile) {
		try{
			try{
            	is = new URL(getDocumentBase(), infile).openStream();
             }catch(MalformedURLException ignored){}
    		StreamTokenizer d = new StreamTokenizer(is);
    		int i=0; int j=0;
    		if  (d.nextToken() != d.TT_EOF) numCols = (int)(d.nval);
    		if  (d.nextToken() != d.TT_EOF) numRows = (int)(d.nval);
      		Z = new int [numCols+2*b][numRows+2*b];
      		while (d.nextToken() != d.TT_EOF) {
       			Z[j+b][i+b] = (int)(d.nval);
        		j++;
       		 	if (j == numCols){//next row
        		  	j = 0;
          			i++;
       	 		}  
      		}
    	}catch (IOException ignored) { }
	}
	
	public void setParameters(){
		infile = getParameter("infile");
		if ( infile == null) infile="bigman.txt";
		String s = getParameter("2D");
		if ( s == null) {
			stereogram = true;
		} else {
			stereogram = false;
		}
		s = getParameter("DPI");
		if (s == null) {
			DPI = 72;
		}else {
			DPI = Integer.parseInt(s); 
		}
		s = getParameter("border");
	
		if (s == null) {
			b = 0;
		}else {
			b = Integer.parseInt(s); 
		}
		s = getParameter("factor");
		if (s == null) {
			f = 1;
		}else {
			f = Integer.parseInt(s); 
		}
		s = getParameter("color");
		if (s == null) {
			dotColor = 0;
		}else {
			dotColor = Integer.parseInt(s); 
		}
		
		DPI=DPI/f;
		E = (int)(Math.round(2.5*DPI));	
		 
	}
	public void createSIRD( Graphics g) {
	
		if (stereogram){
			g.drawString( "Stereogram being initialized", 30, 30 );
			g.drawString( "Data from "+infile+"  "+DPI+" DPI", 30, 50 );
		  for ( y =0 ; y < numRows+2*b; y++) {
		   	pix  = new Color[numCols+2*b];
			same = new int[numCols+2*b];
		
			for (x = 0; x < numCols+2*b; x++) same[x] = x;
			//calc links for the depth
			for ( x = 0; x < numCols+2*b; x++) {
				s = separation ((int)(Z[x][y]));
				left = x - (s/2);
				right = left + s;
				if ( 0 <= left && right < numCols){
					int k;
					for (k=same[left]; k != left && k != right; k=same[left])
						if ( k < right)
							left = k;
						else {
							left = right;
							right = k;
						}
					same[left] = right;
				}
			}
			// assign the colors
			
			
			for (x = numCols+2*b-1; x >= 0; x--) {
				if (same[x] == x ) pix [x] = RandomColor();
				else pix[x] = pix[same[x]];
				g.setColor(pix[x]);
				g.fillRect( x*f, y*f, f, f);
			}
		  }
		} if (!stereogram){
			g.setColor(RandomColor());
			 for ( y =0 ; y < numRows+2*b; y++) for (x = numCols+2*b-1; x >= 0; x--) {
				if (!(Z[x][y]==0)) g.fillRect( x*f, y*f, f, f);
			}
			g.setColor(Color.black);
			g.drawString( "Stereogram", 10, 10 );
			g.drawString( "Data from "+infile+"  "+DPI+" DPI", 10, 25 );
			g.drawString( "factor = "+f+", Border =  "+b+" pixels", 10, 40 );
		}
	
	}
	
	public void init() {
	
		//getParameter("imageName")
		setParameters();
		
		
		
		readFile(infile);	
		  	
    	resize(f*(numCols+2*b),f*(numRows+2*b));
		setBackground(Color.white);
		img = createImage ( f*(numCols+2*b),f*(numRows+2*b));
		gr = img.getGraphics();
		createSIRD(gr);
		
		
	}
	public Color RandomColor () {
		Color c = null;
		switch (dotColor) {
			case (1) :	// blue
				c= new Color(5,
				(int)(Math.random()*255),
				(int)(Math.random()*255));
				break;
			case (2) : // purple
				c= new Color(
				(int)(Math.random()*255),
				5,
				(int)(Math.random()*255));
				break;
			case (3) : // yellow-green
				c= new Color(
				(int)(Math.random()*255),
				(int)(Math.random()*255),
				5);
				break;
			case (4) : // woody-red
				c= new Color(
				(int)(Math.random()*255),
				(int)(Math.random()*100),5);
				break;
			default:  // tutti-fruti
				c= new Color(
				(int)(Math.random()*255),
				(int)(Math.random()*255),
				(int)(Math.random()*255));
		}
		return c;
	}
	public void paint( Graphics g ) {
	 
		g.drawImage(img, 0,0,null);
	}

}