/*
 * BugEyes.java
 *	  Distort an image
 *	  Usage:  <applet code="BugEyes.class width=100 height=100>
 *		  <param name="image" value="foo.gif">
 *		  </applet>
 *
 * Ken Shirriff		 ken.shirriff@eng.sun.com
 *
 * Copyright (c) 1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 *
 * Please refer to the file "license.txt"
 * for further important copyright and licensing information.
 */

import java.awt.*;
import java.awt.image.*;
import java.applet.Applet;


public class BugEyes extends Applet implements Runnable, ImageObserver {
	int width, height;
	Image origimg=null, dispimg=null;
	Graphics gr;
	Thread warpthread = null;
	int pix[] = null;
	boolean down=false;
	boolean gotdata=false;
	boolean runningok=false;
	String status="Loading image";
	Warp warp=new Warp2();
	MediaTracker tracker;
	int mx0=0,my0=0,mx1=0,my1=0;
	static double param = 1;
	Scrollbar scroll = null;
	Button reset = null;
	Canvas can = null;
	int topmarg=0;
	int leftmarg=0;

	public void start() {
		warpthread=null;
		repaint();
	}
	public void stop() {
		if (warpthread!=null) {
			warpthread.stop();
			warpthread = null;
		}
		repaint();
	}

	public boolean imageUpdate(Image origimg, int infoflags, int x, int y,
	int w, int h) {
		repaint();
		return true;
	}

	public void init() {
		int i;
		String image = null;
		tracker = new MediaTracker(this);
		if (getParameter("image") != null) {
			image = getParameter("image");
		} else {
			showStatus("BugEyes: no image specified");
			return;
		}

		showStatus(status);
		origimg = getImage(getDocumentBase(),image);
		if (origimg==null) {
			status = "BugEyes: failed to load image";
			showStatus(status);
			return;
		}
		tracker.addImage(origimg,0);
		try {
			tracker.waitForAll();
		} catch (InterruptedException e) { }
		if (tracker.isErrorAny()) {
			status = "BugEyes: Error loading image";
			showStatus(status);
			return;
		}

		width = origimg.getWidth(this);
		height = origimg.getHeight(this);
		can = new WarpCanvas();
		can.resize(width, height);

		GridBagLayout gridbag = new GridBagLayout();
		GridBagConstraints gc = new GridBagConstraints();
		setLayout(gridbag);
		gc.anchor = GridBagConstraints.NORTH;
		gc.gridwidth = GridBagConstraints.REMAINDER;
		gridbag.setConstraints(can,gc);
		add(can);
		scroll = new Scrollbar(Scrollbar.HORIZONTAL,0,20,0,100);
		scroll.setValue(100);
		gc.gridwidth = 1;
		Label sh = new Label("Shrink");
		gridbag.setConstraints(sh,gc);
		add(sh);
		gc.fill = GridBagConstraints.HORIZONTAL;
		gc.weightx=1;
		gridbag.setConstraints(scroll,gc);
		add(scroll);
		gc.gridwidth = GridBagConstraints.REMAINDER;
		gc.weightx=0;
		gc.fill = GridBagConstraints.NONE;
		Label ex = new Label("Expand");
		gridbag.setConstraints(ex,gc);
		add(ex);
		reset = new Button("Reset");
		gc.gridwidth = GridBagConstraints.REMAINDER;
		gridbag.setConstraints(reset,gc);
		add(reset);
		Panel buf = new Panel();
		gc.fill = GridBagConstraints.BOTH;
		gridbag.setConstraints(buf,gc);
		add(buf);
		super.layout();
		topmarg = can.bounds().y;
		leftmarg = can.bounds().x;

		runningok=true;
		status = "BugEyes by Ken Shirriff";
		showStatus(status);
	}

	public boolean handleEvent(Event e) {
		if (e.target.equals(scroll)) {
			param = scroll.getValue()/100.*2-1;
		}
		return super.handleEvent(e);
        }


	public void update(Graphics g) {
		paint(g);
	}
	public void paint(Graphics g) {
		if (!runningok) {
			return;
		}
		if (pix==null) {
			// Create the pixel array the first time and fill
			// it with the image's pixels.
			pix = new int[width*height];
			PixelGrabber grabber = new PixelGrabber(origimg, 0,0,width,height,pix,0,width);
			try {
				boolean s = false;
				while (s==false) {
					s = grabber.grabPixels();
				}
			} catch (InterruptedException e) { }
			gotdata = true;
			dispimg = createImage(new MemoryImageSource(width, height, pix, 0, width));
		}
		can.getGraphics().drawImage(dispimg,0,0,width,height,this);
		if (down) {
			warp.rubberBand(can.getGraphics(),mx0,my0,mx1,my1);
		}
	}


	public void run() {
		Image newimg;
		if (gotdata) {
			warp.warp(dispimg, width, height, mx0,my0,mx1,my1,pix);
			newimg = createImage(new MemoryImageSource(width, height, pix, 0, width));
			tracker.addImage(newimg,0);
			try {
				tracker.waitForAll();
			} catch (InterruptedException e) { }
			dispimg = newimg;
		}
		repaint();
		status = "BugEyes by Ken Shirriff";
		showStatus("");
		warpthread = null;
	}

	public boolean mouseEnter(java.awt.Event evt, int xm, int ym) {
		showStatus(status);
		return true;
	}

	public boolean mouseExit(java.awt.Event evt, int xm, int ym) {
		showStatus("");
		return true;
	}

	public boolean mouseDown(java.awt.Event evt, int xm, int ym) {
		showStatus("Select the region");
		if (warpthread == null) {
			down = true;
			mx0 = xm-leftmarg;
			my0 = ym-topmarg;
			mx1 = xm-leftmarg;
			my1 = ym-topmarg;
			repaint();
		}
		return true;
	}

	public boolean mouseDrag(java.awt.Event evt, int xm, int ym) {
		showStatus("Selecting region");
		mx1 = xm-leftmarg;
		my1 = ym-topmarg;
		repaint();
		return true;
	}

	public boolean mouseUp(java.awt.Event evt, int xm, int ym) {

		showStatus("Selected");
		down = false;
		mx1 = xm-leftmarg;
		my1 = ym-topmarg;
		repaint();
		if (warpthread==null) {
			status = "Warping image";
			showStatus(status);
			warpthread = new Thread(this);
			warpthread.start();
		}
		return true;
	}

	public boolean action(Event e, Object o) {
		if (e.target.equals(reset)) {
			pix = null;
			repaint();
		}
		return true;
	}

	public String getAppletInfo() {
			return "Distort by Ken Shirriff  shirriff@eng.sun.com";
	}

	public String[][] getParameterInfo() {
		String [][] info = {
		{"width	  ","int		", "image width"},
		{"height	 ","int		", "image height"},
		{"image	  ","String	 ", "image url"}
	};
	return info;
	}
}


abstract class Warp {
	public void rubberBand(Graphics g, int x0, int y0, int x1, int y1) {
		g.drawLine(x0,y0,x1,y1);
	}
	abstract void warp(Image origimg, int width, int height, int x0, int y0, int x1, int y1,
		int pix[]);

	public void circ(Graphics g, int x0, int y0, int x1, int y1) {
		int r = (int)Math.sqrt((x1-x0)*(x1-x0)+(y1-y0)*(y1-y0));
		g.drawOval(x0-r,y0-r,2*r,2*r);
	}
	public void grab(Image origimg,int x0,int y0,int w,int h,int width,
	int height,int inpxls[], int outpxls[]) {
		int off = 0;
		int realw=w, realh=h, realx0=x0, realy0=y0;
		if (x0<0) {
			realx0 = 0;
		}
		if (y0<0) {
			realy0 = 0;
		}
		for (int x=realx0;x<x0+h;x++) {
			if (x>=width) {
				break;
			}
			for (int y=realy0;y<y0+h;y++) {
				if (y>=height) {
					break;
				}
				outpxls[x-x0+(y-y0)*w]=inpxls[x+y*width];
			}
		}
	}

}

// Warp the image.  Note that different warp classes can be plugged in.
class Warp2 extends Warp {
	public void rubberBand(Graphics g, int x0, int y0, int x1, int y1) {
		circ(g,x0,y0,x1,y1);
	}

	public void warp(Image origimg, int width, int height, int x0, int y0, int x1, int y1,
		int pix[]) {
		int r2 = (x1-x0)*(x1-x0)+(y1-y0)*(y1-y0);
		int r = (int)Math.sqrt((x1-x0)*(x1-x0)+(y1-y0)*(y1-y0));
		if (r==0) {
			return;
		}
		int pixbak[] = new int[(2*r+1)*(2*r+1)];
		grab(origimg,x0-r,y0-r,2*r+1,2*r+1,width,height,pix,pixbak);

		for (int yd=-r;yd<=r;yd++) {
			int y = y0+yd;
			if (y>=0 && y<height) {
				int xw = (int)Math.sqrt(r2-yd*yd);
				for (int xd=-xw;xd<=xw;xd++) {
					int x = x0+xd;
					if (x>=0 && x<width) {
						// r0 = 0 to 1
						double r0 =Math.sqrt((xd*xd+yd*yd))/(double)r;
						// new radius = r1.
						// sc = r1/r0 or r1=sc*r0
						double sc = r0*BugEyes.param+1-BugEyes.param;

						int xa = (int)(r+xd*sc+.5);
						int ya = (int)(r+yd*sc+.5);
						if (xa>2*r) {
							xa = 2*r;
						}
						if (ya>2*r) {
							ya = 2*r;
						}
						if (xa<0) {
							xa = 0;
						}
						if (ya<0) {
							ya = 0;
						}
						pix[x+y*width]=pixbak[xa+ya*(2*r+1)];
					}
				}
			}
		}
	}
}

class WarpCanvas extends Canvas {
	public void update(Graphics g) {
		paint(g);
	}
	public void paint(Graphics g) {
	}
}