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

public class spectrometer extends Applet implements Runnable
{
	Thread	 m_spectrometer = null;

	private Graphics offScreenGraphics;
	private Image offScreen;
	private Image box, neg_box, gas_cell, neg_gas_cell, lamp, neg_lamp;

	private int rainbowPixels[] = new int[400];
	private double absorbance[] = new double[400];
	private Color beamColor, absdColor;
	private boolean lightOn = true;
	private boolean running = false;
	private boolean paused = false;

	private Button Light = new Button("Light");
	private Button Start = new Button("Start");
	private Button Pause = new Button("Pause");
	private Button Stop = new Button("Stop");

	private Label blank1 = new Label(" ",Label.CENTER);
	private Label blank2 = new Label(" ",Label.CENTER);
	private Label blank3 = new Label(" ",Label.CENTER);
	private Label blank4 = new Label("Stopped",Label.CENTER);
	private Label blank5 = new Label(" ",Label.CENTER);
	private Label blank6 = new Label(" ",Label.CENTER);

	private Panel Controls = new Panel();

	public spectrometer()
	{
	}

	public String getAppletInfo()
	{
		return "Name: spectrometer\r\n" +
		       "Author: Dr. P. Bird\r\n" +
			   "Copyright, September 1997\r\n" +
		       "Created with Microsoft Visual J++ Version 1.0";
	}


	public void init()
	{
//		resize(630, 310);

		setLayout(new BorderLayout());				
		Controls.setLayout(new GridLayout(1,8,0,0));
		Controls.add(Light);
		Controls.add(blank3);
		Controls.add(Start);
		Controls.add(Pause);
		Controls.add(Stop);
		Controls.add(blank4);
		Controls.add(blank5);
		Light.enable();
		Start.disable();
		Pause.disable();
		Stop.disable();

		add("South",Controls);

		generateRainbow();
		generateSpectrum();

		offScreen = createImage(630,250);
		offScreenGraphics = offScreen.getGraphics();

		MediaTracker tracker = new MediaTracker(this);	  //Get .gifs
 		box = getImage(getDocumentBase(), "box.gif");
		tracker.addImage(box,1);
		neg_box = getImage(getDocumentBase(), "neg-box.gif");
		tracker.addImage(neg_box,2);
		gas_cell = getImage(getDocumentBase(), "gas-cell.gif");
		tracker.addImage(gas_cell,3);
  		neg_gas_cell = getImage(getDocumentBase(), "neg-gas-cell.gif");
		tracker.addImage(neg_gas_cell,4);
		lamp = getImage(getDocumentBase(), "lamp.gif");
		tracker.addImage(lamp,5);
		neg_lamp = getImage(getDocumentBase(), "neg-lamp.gif");
		tracker.addImage(neg_lamp,6);

		try
		{
			tracker.waitForAll();
			if (tracker.isErrorAny())
			{
				showStatus("Error loading the images");
				stop();
			}
		}
		catch(InterruptedException e)
		{
			showStatus("InterruptedException (Tracker)");
			stop();
		}
	}

	// calculate the virtual spectrum

	public void generateRainbow()
	{
		int red = 0; int green = 0; int blue = 0;

		for (int i = 0; i < 400; i++)  //construct a rainbow
		{
			if (i < 60)
			{
				red = (int)(255.0D*0.4D*
				(0.5D - 0.5D*Math.cos(Math.PI*(double)(i)/55.0D))
				);
				green = 0;
				blue = (int)(255.0D*
				(0.5D - 0.5D*Math.cos(Math.PI*(double)(i)/110.0D))
				);
			}
			if ((i >= 60) & (i < 120))
			{
				red = (int)(255.0D*0.4D*
				(0.5D*Math.cos(Math.PI*(double)(i - 60)/55.0D) + 0.5D)
				);
				green = (int)(255.0D*
				(0.5D - 0.5D*Math.cos(Math.PI*(double)(i - 60)/110.0D))
				);
				blue = (int)(255.0D*
				(0.5D - 0.5D*Math.cos(Math.PI*(double)(i)/110.0D))
				);
			}
			if ((i >= 120) & (i < 180))
			{
				red = 0;
				green = (int)(255.0D*
				(0.5D - 0.5D*Math.cos(Math.PI*(double)(i - 60)/110.0D))
				);
				blue = (int)(255.0D*
				(0.5D*Math.cos(Math.PI*(double)(i - 110)/110.0D) + 0.5D)
				);
			}
			if ((i >= 180) & (i < 240))
			{
				red = (int)(255.0D*
				(0.5D - 0.5D*Math.cos(Math.PI*(double)(i - 180)/110.0D))
				);
				green = 255;
				blue = (int)(255.0D*
				(0.5D*Math.cos(Math.PI*(double)(i - 110)/110.0D) + 0.5D)
				);
			}
			if ((i >= 240) & (i < 290))
			{
				red = (int)(255.0D*
				(0.5D - 0.5D*Math.cos(Math.PI*(double)(i - 180)/110.0D))
				);
				green = (int)(255.0D*
				(0.5D*Math.cos(Math.PI*(double)(i - 240)/110.0D) + 0.5D)
				);
			}
			if ((i >= 290) & (i < 350))
			{
				red = (int)(255.0D*
				(0.5D*Math.cos(Math.PI*(double)(i - 290)/110.0D) + 0.5D)
				);
				green = (int)(255.0D*
				(0.5D*Math.cos(Math.PI*(double)(i - 240)/110.0D) + 0.5D)
				);
				blue = 0;
			}
			if ((i >= 350) & (i < 400))
			{
				red = (int)(255.0D*
				(0.5D*Math.cos(Math.PI*(double)(i - 290)/110.0D) + 0.5D)
				);
				green = 0;
				blue = 0;
			}
				rainbowPixels[i] = 
					255 << 24 | red << 16 | green << 8 | blue;
		}
	}

	public void generateSpectrum()
	{
		double x;
	
		for (int i = 0; i <	400; i++)	 
		{
			x = i;
			absorbance[i] = 							//two Gaussians
				0.8*Math.exp(-(6-x/20.0)*(6-x/20.0))	
					+ 0.5*Math.exp(-(13.0-x/20.0)*(13.0-x/20.0));
		}
	}

	public void destroy()
	{
	}

	public void paint(Graphics g)
	{
	}

	public synchronized void update(Graphics g)
	{
		g.drawImage(offScreen,0,0,null);
	}

	public void start()
	{
		if (m_spectrometer == null)
		{
			m_spectrometer = new Thread(this);
			m_spectrometer.start();
		}
	}
	
	public void stop()
	{
		if (m_spectrometer != null)
		{
			m_spectrometer.stop();
			m_spectrometer = null;
		}
	}

	public void run()
	{
		int index=40;
		int j;
		double rd, gr, bl;
		double rd_absd, gr_absd, bl_absd;
		double transmission;

		int plotter_x1 = 470, plotter_x2 = 540, plotter_y = 130;
		int graph_x = 0, graph_y = 0;

		int w = 110;
		int h = 60;
		int[]  pixels  =  new  int[w  *  h];

		while (true)
		{
			try
			{
				if (!running) 	  //refresh while waiting
				{
					drawApparatus();
					Thread.sleep(20);
					pen(535,130,540,470,130,false);
					
					index = 40;
				}
				while (!running)
				{
					Thread.sleep(100);
					repaint();
				}

				beamColor = new Color(rainbowPixels[index]);
				rd = beamColor.getRed();
				gr = beamColor.getGreen();
				bl = beamColor.getBlue();
				offScreenGraphics.setColor(beamColor);
				offScreenGraphics.fillRect(130,107,70,11);	 //draw incident beam
				if (lightOn)
					offScreenGraphics.setColor(Color.black);
				else
  					offScreenGraphics.setColor(Color.white);
				offScreenGraphics.drawLine(192,107,192,117); //patches cell (left)
  
				for (int i = 0; i < 36; i++)				//draw beam in sample
				{
					transmission = 1.0 - (double)(i)*(absorbance[index])/36.0;
					rd_absd = rd*transmission;
					gr_absd = gr*transmission;
					bl_absd = bl*transmission;
					absdColor = new Color
						(255 << 24 | (int)rd_absd 
						<< 16 | (int)gr_absd 
						<< 8 | (int)bl_absd);
					offScreenGraphics.setColor(absdColor);
					offScreenGraphics.drawLine(i+200,107,i+200,117);
				}
				
				offScreenGraphics.fillRect(236,107,60,11);	 //draw exit beam
  				if (lightOn)
					offScreenGraphics.setColor(Color.black);
				else
  					offScreenGraphics.setColor(Color.white);
				offScreenGraphics.drawLine(229,107,229,117); //patch cell (right)

//				repaint(130,107,266,11);
				repaint();

				if(lightOn)									 //re-draw lamp	area
				{
					offScreenGraphics.setColor(Color.white); //this code is not called
					offScreenGraphics.fillRect(420,0,256,205); //(no scan with light on)
					offScreenGraphics.drawImage(lamp,370,0,null);
					offScreenGraphics.setColor(Color.black);
 					offScreenGraphics.drawLine(400,133,450,150); // wire to recorder

				}
				else
				{
					offScreenGraphics.drawImage(neg_lamp,370,0,null);
					offScreenGraphics.setColor(Color.black);
					offScreenGraphics.drawLine(430,143,450,150);  //wire to recorder
					offScreenGraphics.setColor(Color.white);
					offScreenGraphics.drawLine(400,133,430,143);
				}
				for (int i = 36; i <= index; i++)				 //plot curve so far
				{
					offScreenGraphics.setColor(Color.red);
					j = (i-36)/5;
					graph_x = 535-(int)(absorbance[i]*80.0) - 15*j/45;
					graph_y = 130+j;
					plotter_y = graph_y;
					plotter_x1 = 540 - 15*j/60;
					plotter_x2 = 470 - 37*j/60;
					offScreenGraphics.drawLine
						(graph_x,graph_y,graph_x,graph_y);	//plot point
				}	

 				pen(graph_x,graph_y, plotter_x1, plotter_x2, plotter_y,true); //plot pen
				repaint(370,0,260,200);
				Thread.sleep(50);					  //controls plot speed
				if (running & !paused) index++;
				if (index == 340)
				{
					index = 40;
					blank4.setText("Restarting");
//
					for (int k = 60; k >= 0; k--)	   //run pen back to beginning
					{
						graph_y = 130+k;
						graph_x = 535 - 15*k/45;
						plotter_y = graph_y;
						plotter_x1 = 540 - 15*k/60;
						plotter_x2 = 470 - 37*k/60;

						offScreenGraphics.drawImage(neg_lamp,370,0,null);
						offScreenGraphics.setColor(Color.black);
						offScreenGraphics.drawLine(430,143,450,150);  //wire to recorder
						offScreenGraphics.setColor(Color.white);
						offScreenGraphics.drawLine(400,133,430,143);				
						
						pen(graph_x, graph_y, plotter_x1, plotter_x2, plotter_y,false);
						repaint(370,0,200,260);
						Thread.sleep(30);			 //controls flyback speed
					}
					Thread.sleep(500);
					blank4.setText("Running");
				}
			}
			catch (InterruptedException e)
			{
				stop();
			}
		}
	}

 	private void drawApparatus()
	{
		if (lightOn)
		{
			offScreenGraphics.setColor(Color.white);	//draw gif's
			offScreenGraphics.fillRect(0,0,629,249);
			offScreenGraphics.drawImage(box,10,70,null);
			offScreenGraphics.drawImage(gas_cell,180,80,null);
			offScreenGraphics.drawImage(box,280,70,null);
			offScreenGraphics.drawImage(lamp,370,0,null);
			offScreenGraphics.setColor(Color.black);
			offScreenGraphics.drawLine(400,133,450,150); // wire to recorder
			offScreenGraphics.drawLine(129,107,129,119);
			offScreenGraphics.drawLine(130,106,130,118);
			offScreenGraphics.drawLine(131,105,131,117);
			offScreenGraphics.setColor(Color.green.darker().darker());
			offScreenGraphics.drawString("Source",55,165);	  //labels
			offScreenGraphics.drawString("Sample",194,153);
			offScreenGraphics.drawString("Detector",320,165);
			offScreenGraphics.drawString("Recorder",460,220);
			offScreenGraphics.setColor(Color.gray);
			offScreenGraphics.drawString("Copyright 1998, Peter H. Bird",10,235);
			offScreenGraphics.setColor(Color.black);
		}
		else
		{
			offScreenGraphics.setColor(Color.black);
			offScreenGraphics.fillRect(0,0,629,249);
			offScreenGraphics.drawImage(neg_box,10,70,null);  //draw gif's
			offScreenGraphics.drawImage(neg_gas_cell,180,80,null);
			offScreenGraphics.drawImage(neg_box,280,70,null);
			offScreenGraphics.drawImage(neg_lamp,370,0,null);
			offScreenGraphics.setColor(Color.black);
			offScreenGraphics.drawLine(129,107,129,119);
			offScreenGraphics.drawLine(130,106,130,118);
			offScreenGraphics.drawLine(131,105,131,117);
			offScreenGraphics.drawLine(430,143,450,150);  //wire to recorder
			offScreenGraphics.setColor(Color.white);
			offScreenGraphics.drawLine(400,133,430,143);
		}
	}


	public synchronized boolean action(Event evt, Object obj)
	{
		String sButtonLabel;
		Object oTarget = evt.target;
		if (oTarget instanceof Button)			  //Only handles buttons clicked
		{
			Button buttonHit = (Button)oTarget;
			sButtonLabel = buttonHit.getLabel();
			if (sButtonLabel.compareTo("Light") == 0)
			{ 
				lightOn = !lightOn;				 //light button
				if(lightOn)
				{
					running = false;
					paused = false;
					Start.disable();
					Stop.disable();
					Pause.disable();
					blank4.setText("Stopped");
				}
				else
				{
 					running = false;
					paused = false;
					Start.enable();
					Stop.disable();
					Pause.disable();
					blank4.setText("Stopped");
				}
				drawApparatus();
				pen(535,130,540,470,130,false);
				repaint();

			}
			if (sButtonLabel.compareTo("Start") == 0)  //start button
			{
				running = true;
				paused = false;
				Start.disable();
				Pause.enable();
				Stop.enable();
				blank4.setText("Running");
			}
			if (sButtonLabel.compareTo("Pause") == 0)  //pause button
			{
				paused = true;
				Start.enable();
				Pause.disable();
				Stop.enable();
				blank4.setText("Paused");
			}
			if (sButtonLabel.compareTo("Stop") == 0)   //stop button
			{
				running = false;
				paused = false;
				Start.enable();
				Pause.disable();
				Stop.disable();
				drawApparatus();
				repaint();
				blank4.setText("Stopped");
			}
			return true;
		}
		return true;
//		return super.action(evt, obj);
	}

		private void pen(int x, int y, int px1, int px2, int py, boolean pp)
	{
		offScreenGraphics.setColor(Color.black);	//draw pen carrier
		offScreenGraphics.drawLine(px1,py-2,px2,py-2);
		offScreenGraphics.drawLine(px1,py-3,px2,py-3);
		offScreenGraphics.drawLine(px1,py,px1,py-2);
		offScreenGraphics.drawLine(px2,py,px2,py-2);

		offScreenGraphics.drawLine(x-1,y-2,x-1,y-11); //draw pen
		if (pp)
			offScreenGraphics.drawLine(x,y,x,y-12);
		else
			offScreenGraphics.drawLine(x,y-2,x,y-12);
		offScreenGraphics.drawLine(x+1,y-2,x+1,y-11);
	}
}