import java.applet.*;
import java.awt.*;
import java.util.Random;
import java.lang.String;
import ImpulseFunctions;

public class Colors3 extends Applet 
{
    // double buffering image
	private Dimension offDim;
    private Image offImage;// offscreen image
    private Graphics offGraphics; // associated graphics object
	private boolean offReady = false;

	int wavelength[] = {480, 580, 680};
	double power[] = {0.5, 0.5, 0.5};
	Color spectrum[] = new Color[198];
	Color powerScale[] = new Color[100];

	int click = -1;

	private int bcount=0;

	public void init()
	{
		int i;
		ImpulseFunctions xyz = new ImpulseFunctions(wavelength, power);

		setBackground(Color.black);
		setForeground(new Color(0x00AA00));
		for (i=0; i<198; i++) spectrum[i]=rgb(xyz.getx(i*2+380)*2.0,xyz.gety(i*2+380)*2.0,xyz.getz(i*2+380)*2.0); 
		for (i=0; i<100; i++) powerScale[i]=rgb(xyz.getx(520)*i/100.0,xyz.gety(520)*i/100.0,xyz.getz(520)*i/100.0); 
		offDim = new Dimension(300,300);
		offImage = createImage(offDim.width, offDim.height);
		offGraphics = offImage.getGraphics();
		repaint();
	}

	public void start()
	{
		requestFocus();
		repaint();
	}

	public void paint(Graphics g)
	{
		if (offReady) g.drawImage(offImage, 0, 0, null);
		else update(g);
	}

	Color rgb (double X, double Y, double Z)
	{
		float r, g, b;

		r=(float)(3.2410*X-1.5374*Y-0.4986*Z)/3.0f;
		g=(float)(-0.9692*X+1.8760*Y+0.0416*Z)/3.0f;
		b=(float)(0.0556*X-0.2040*Y+1.0570*Z)/3.0f;
		if (r<0.0) r=0.0f;
		if (g<0.0) g=0.0f;
		if (b<0.0) b=0.0f;
		if (r<=0.00304) r*=12.92;
		else r=1.055f*(float)Math.exp(Math.log(r)/2.4)-0.055f;
		if (g<=0.00304) g*=12.92;
		else g=1.055f*(float)Math.exp(Math.log(g)/2.4)-0.055f;
		if (b<=0.00304) b*=12.92;
		else b=1.055f*(float)Math.exp(Math.log(b)/2.4)-0.055f;
		if (r>1.0) r=1.0f;
		if (g>1.0) g=1.0f;
		if (b>1.0) b=1.0f;
		return new Color(r,g,b);
	}

    public void update(Graphics g)
    {
		int i;
		ImpulseFunctions xyz = new ImpulseFunctions(wavelength, power);
		double X = xyz.computeX();
		double Y = xyz.computeY();
		double Z = xyz.computeZ();
		double x = X/(X+Y+Z);
		double y = Y/(X+Y+Z);

        Color colFG = getForeground();
        Color colBG = getBackground();
   	    offGraphics.setColor(Color.black); 
		offGraphics.fillRect(0, 0, offDim.width, offDim.height);
   	    offGraphics.setColor(Color.white);
		offGraphics.drawRect(0, 0, offDim.width-1, offDim.height-1);
   	    offGraphics.setColor(rgb(X,Y,Z));
		offGraphics.drawRect(45, 3, 204, 107);
		offGraphics.drawRect(44, 2, 206, 109);
		for (i=0; i<3; i++) {
			if (click==i) offGraphics.setColor(Color.white);
			else offGraphics.setColor(Color.gray);
			offGraphics.drawLine((wavelength[i]-380)/2+51, 104,
				                 (wavelength[i]-380)/2+51, 104-(int)Math.round(power[i]*100));
			offGraphics.drawString(Double.toString(power[i]), 160, 145+i*15);
			offGraphics.drawString(Integer.toString(wavelength[i]), 100, 145+i*15);
		} 
		for (i=0; i<198; i++) {
			offGraphics.setColor(spectrum[i]);
			offGraphics.drawLine(i+51, 105, i+51, 108);
		}
		for (i=0; i<100; i++) {
			offGraphics.setColor(powerScale[i]);
			offGraphics.drawLine(47, 103-i, 50, 103-i);
		}
   	    offGraphics.setColor(Color.magenta);
		offGraphics.drawString("Wavelength", 80, 130);
		offGraphics.drawString("Power", 160, 130);
   	    offGraphics.setColor(Color.blue);
		offGraphics.drawString("X", 80, 200);
   	    offGraphics.setColor(Color.white);
		offGraphics.drawString(Double.toString(X), 100, 200);
   	    offGraphics.setColor(Color.blue);
		offGraphics.drawString("Y", 80, 215);
   	    offGraphics.setColor(Color.white);
		offGraphics.drawString(Double.toString(Y), 100, 215);
   	    offGraphics.setColor(Color.blue);
		offGraphics.drawString("Z", 80, 230);
   	    offGraphics.setColor(Color.white);
		offGraphics.drawString(Double.toString(Z), 100, 230);
   	    offGraphics.setColor(Color.cyan);
		offGraphics.drawString("Y", 80, 245);
   	    offGraphics.setColor(Color.white);
		offGraphics.drawString(Double.toString(Y), 100, 245);
   	    offGraphics.setColor(Color.cyan);
		offGraphics.drawString("x", 80, 260);
   	    offGraphics.setColor(Color.white);
		offGraphics.drawString(Double.toString(x), 100, 260);
   	    offGraphics.setColor(Color.cyan);
		offGraphics.drawString("y", 80, 275);
   	    offGraphics.setColor(Color.white);
		offGraphics.drawString(Double.toString(y), 100, 275);
		offReady=true;
		paint(g);
    }

	public boolean mouseUp(Event e, int x, int y) 
	{
		int wl;
		double pwr;

		if (click>=0) {
			wl=380+(x-51)*2;
			pwr=(104-y)/100.0;
			if (wl<380) wl=380;
			if (wl>774) wl=774;
			if (pwr<0.0) pwr=0.0;
			if (pwr>1.0) pwr=1.0;
			wavelength[click]=wl;
			power[click]=pwr;
			click=-1;
			repaint();
			return true;
		}
		return false;
	}

	public boolean mouseDrag(Event e, int x, int y) 
	{
		int wl;
		double pwr;

		if (click>=0) {
			wl=380+(x-51)*2;
			pwr=(104-y)/100.0;
			if (wl<380) wl=380;
			if (wl>774) wl=774;
			if (pwr<0.0) pwr=0.0;
			if (pwr>1.0) pwr=1.0;
			wavelength[click]=wl;
			power[click]=pwr;
			repaint();
			return true;
		}
		return false;
	}

	int sqr (int i)
	{
		return i*i;
	}

	public boolean mouseDown(Event e, int x, int y) 
	{
		int wl, i, dist, minDist;
		double pwr;

		if ((x > 50) && (x < 50+198) && (y>3) && (y<104)) {
			minDist=Integer.MAX_VALUE;
			wl=380+(x-51)*2;
			pwr=(104-y)/100.0;
			for (i=0; i<3; i++) {
				dist=sqr(wavelength[i]-wl)+sqr((int)Math.round((power[i]-pwr)*100));
				if (dist<minDist) {
					minDist=dist;
					click=i;
				}
			}
			wavelength[click]=wl;
			power[click]=pwr;
			repaint();
			return true;
		} else click=-1;
		return false;
	}
}