/**myArtTrip2.java modified by gregvan v1.1
 *based on work by Dr.Sharon Tuttle
*Humboldt State University, California,USA
 * RECOMMENDED SIZE: height 400, width 600
 **/


import java.applet.*;
import java.awt.*;

public class myArtTrip2 extends Applet implements Runnable
{
        //-----
        // data fields
        //-----
 int rr,gg,bb;//color variables       
        int       x, y;
int z=0;
int a=0;
        
        Thread    myRunner;
Color cNew = new Color(125, 0, 255);
Color bNew = new Color(0, 0, 0);

        Image     buffer;          // [1]"the off-screen image for double-buffering"
        Dimension appletSize;      // [1]"the size of the applet"
        Graphics  bufferGraphics;  // [1]"a Graphics object for the buffer"

       
        //-----
        // methods
        //-----
        
        public void init()
        {
                Font chosenFont = new Font("Dialog", Font.PLAIN, 30); 
            
                setBackground(Color.black);
                System.out.println("myArtTrip2 Version 1.0");
                
                
               
                // get size of applet (appletSize is a Dimension object)
                appletSize = this.getSize();

                // buffer is now created to be the same size as the applet
                buffer = this.createImage(appletSize.width, appletSize.height);

                // get a Graphics object for buffer
                bufferGraphics = buffer.getGraphics();
        }

        public void start()
        {
                if (myRunner == null)
                { 
                        // not bothering to name the thread, this time;
                        myRunner = new Thread(this);
                        myRunner.start();
                }
        }

        public void run()
        {
                Thread  executingThread;
                                
                executingThread = Thread.currentThread();

                while (myRunner == executingThread)
                {
                       

                        repaint();
                        try
                        {
                                // sleep for 1 second (1000 msec = 1 sec)
                                Thread.sleep(1000);
                        }
                        catch(InterruptedException e) 
                        {
                        } 

                        while (myRunner != null)
                        {
                               
                                repaint(); 
                                try
                                {
                                        // pause for .1 second between
                                        // repaintings
                                        Thread.sleep(100);  // .1 second pause
                                }
                                catch (InterruptedException e) 
                                {
                                }
                        }  
                }  //end while thread executing
        }

        //suspends execution when user leaves page
        public void stop()
        { 
                if (myRunner != null)
                {
                        myRunner = null;
                }
        }

        // VERY IMPORTANT --- [1] "It is important to override this method
        // like this for double-buffering" --- this new version of update()
        // doesn't clear the screen, it just calls paint() immediately.
        public void update(Graphics g)
        {
                paint(g);
        }

        // now, when double-buffering, here in paint() I will not paint on
        // Graphics object g --- I will paint on my buffer's Graphics object,
        // instead
        public void paint(Graphics g)
        {
//a for loop to paint 10 lines      
	for (int i=0;i<10;i++)
 	{
//color changer
		rr=rr+1;
		if(rr>255){rr=rr-255;}
		gg=gg+2;
		if(gg>255){gg=gg-255;}
		bb=bb+3;
		if(bb>255){bb=bb-255;}
//move the endpoints of the lines
		z=z+1;
		if(z>600){z=0;}
		a=a+2;
		if(a>400){a=0;}	
		x=x+3;
		if(x>600){x=0;}
		y=y-1;
		if(y<0){y=400;}	
//apply the new numbers for color
		Color cNew = new Color(rr, gg, bb);
		bufferGraphics.setColor(cNew);	
//draw the lines
		bufferGraphics.drawLine( x, y, z,a);
		bufferGraphics.drawLine( 600-x,y,600-z,a);
//draw the lines with x and z switched
		bufferGraphics.drawLine( z, y, x,a);
		bufferGraphics.drawLine( 600-z,y,600-x,a);
//draw the lines with x and z switched
		bufferGraphics.drawLine( z, y, a,x);
		bufferGraphics.drawLine( 600-z,y,600-a,x);
//bNew is black and white because all values are the same
		Color bNew = new Color(rr, rr, rr);
		bufferGraphics.setColor(bNew);
//draw lines with x-y switched and a-z switched	
		bufferGraphics.drawLine( y, 400-x, a,400-z);
		bufferGraphics.drawLine( 600-y,400-x,600-a,400-z);
                
	}//end of for loop
// [1]"then copy the off-screen buffer onto the screen"
                // (think: why 0,0 for coordinates, here?)
                g.drawImage(buffer, 0, 0, this);
        }
}