import java.awt.*;
import java.awt.event.*;
import java.awt.event.ItemListener;
import java.awt.event.ItemEvent;
import java.applet.Applet;

public class slice extends Applet implements ItemListener {
  CurvePanel mainpanel;
  Button plusButton,minusButton,upButton,downButton,leftButton,rightButton,resetButton;
  Checkbox singleCross, multiCross, approx;
  CheckboxGroup cbg;
//double tr[][] = {{1,0,0},{0,1,0},{0,0,1}}; 
double tr[][] = {{Math.cos(5/36.*Math.PI),0,-Math.sin(5/36.*Math.PI)},
  {-Math.sin(5/36.*Math.PI)*Math.sin(5/36.*Math.PI), 
  Math.cos(5/36.*Math.PI),-Math.sin(5/36.*Math.PI)*Math.cos(5/36.*Math.PI)},
  {Math.sin(5/36.*Math.PI)*Math.cos(5/36.*Math.PI),Math.sin(5/36.*Math.PI),    Math.cos(5/36.*Math.PI)*Math.cos(5/36.*Math.PI)}};
double sin5 = Math.sin(5/180.*Math.PI), cos5 = Math.cos(5/180.*Math.PI);
double temp,volume,aveArea;
double t0,x1,y1,z1,x0,y0,z0;
int curvex[]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
int curvey[]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

double yt1(double t) {double z=5*(1-t)+.09004962810*t ;
	return -1.3*(.005787858720*z*z*z-.05447596853*z*z+.1096702813*z+.09006546675) ;}
double zt1(double t) {return 5*(1-t)+.09004962810*t ;}
double yt2(double t) {double z=2.034443936*t + 4.612720328*(1-t); return .13*Math.sin(z) ;}
double zt2(double t) {double z=2.034443936*t + 4.612720328*(1-t); return .1+.1*Math.cos(z) ;}
double yt3(double t) {double z =  .05527864044*(1-t)+5*t;
	return 1.3*(.01783935569*z*z*z-.1959451301*z*z+.5214996241*z+.06121067058);}
double zt3(double t) {return .05527864044*(1-t)+5*t;}
int xtran(double x, double y, double z) {return (int)(200+16*(tr[0][0]*x+tr[0][1]*y+tr[0][2]*z)+.5);}
int ytran(double x, double y, double z) {return (int)(200-16*(tr[1][0]*x+tr[1][1]*y+tr[1][2]*z)+.5);}
double xend,xend0,shrink;
int sliceLoc=0, numSlices=5,numSlabs=3;
double sliceWidth,slabWidth;

  ActionListener resetListener = new ActionListener() {
    public void actionPerformed (ActionEvent e) {
	tr[0][0] = Math.cos(5/36.*Math.PI); tr[0][1] = 0;
	tr[0][2] = -Math.sin(5/36.*Math.PI); tr[1][0] = -Math.sin(5/36.*Math.PI)*Math.sin(5/36.*Math.PI);
	tr[1][1] = Math.cos(5/36.*Math.PI); tr[1][2] = -Math.sin(5/36.*Math.PI)*Math.cos(5/36.*Math.PI);
	tr[2][0] = Math.sin(5/36.*Math.PI)*Math.cos(5/36.*Math.PI); tr[2][1] = Math.sin(5/36.*Math.PI);
	tr[2][2] = Math.cos(5/36.*Math.PI)*Math.cos(5/36.*Math.PI);
	sliceLoc=0; numSlices=5; numSlabs=3;
      mainpanel.repaint();
    }
  };

  ActionListener plusListener = new ActionListener() {
    public void actionPerformed (ActionEvent e) {
	if (singleCross.getSelectedObjects()!=null) {sliceLoc+=2; if (sliceLoc>10) sliceLoc=10;}
	if (multiCross.getSelectedObjects()!=null) numSlices+=1;
	if (approx.getSelectedObjects()!=null) numSlabs+=1;
      mainpanel.repaint();
    }
  };

  ActionListener minusListener = new ActionListener() {
    public void actionPerformed (ActionEvent e) {
	if (singleCross.getSelectedObjects()!=null) {sliceLoc-=2; if (sliceLoc<-10) sliceLoc=-10;}
	if (multiCross.getSelectedObjects()!=null) {numSlices-=1; if (numSlices<1) numSlices=1;}
	if (approx.getSelectedObjects()!=null) {numSlabs-=1; if (numSlabs<1) numSlabs=1;}
      mainpanel.repaint();
    }
  };

  ActionListener upListener = new ActionListener() {
    public void actionPerformed (ActionEvent e) {
	for (int i=0;i<3;i++){
	  temp = tr[1][i]*cos5 + tr[2][i]*sin5; tr[2][i] = -tr[1][i]*sin5 + tr[2][i]*cos5; tr[1][i] = temp;
	}
      mainpanel.repaint();
    }
  };

  ActionListener downListener = new ActionListener() {
    public void actionPerformed (ActionEvent e) {
	for (int i=0;i<3;i++){
	  temp = tr[1][i]*cos5 - tr[2][i]*sin5; tr[2][i] = tr[1][i]*sin5 + tr[2][i]*cos5; tr[1][i] = temp;
	}
      mainpanel.repaint();
    }
  };

  ActionListener leftListener = new ActionListener() {
    public void actionPerformed (ActionEvent e) {
	for (int i=0;i<3;i++){
	  temp = tr[0][i]*cos5 - tr[2][i]*sin5; tr[2][i] = tr[0][i]*sin5 + tr[2][i]*cos5; tr[0][i] = temp;
	}
      mainpanel.repaint();
    }
  };

  ActionListener rightListener = new ActionListener() {
    public void actionPerformed (ActionEvent e) {
	for (int i=0;i<3;i++){
	  temp = tr[0][i]*cos5 + tr[2][i]*sin5; tr[2][i] = -tr[0][i]*sin5 + tr[2][i]*cos5; tr[0][i] = temp;
	}
      mainpanel.repaint();
    }
  };

  public void init(){
    setBackground(Color.white);
    mainpanel = new CurvePanel();
    setLayout(null); 
    mainpanel.setBounds(200,0,399,399); add(mainpanel);  
    setFont(new Font("SansSerif",Font.PLAIN,12));
    plusButton  = new Button("+");     add(plusButton); 
    minusButton = new Button("-");     add(minusButton);
    upButton    = new Button("up");    add(upButton);
    downButton  = new Button("down");  add(downButton);
    leftButton  = new Button("left");   add(leftButton);
    rightButton = new Button("right"); add(rightButton);
    resetButton = new Button("reset"); add(resetButton);
    plusButton.setBounds(100,50,20,20);
    minusButton.setBounds(80,50,20,20);
    upButton.setBounds(80,300,40,20);
    leftButton.setBounds(40,320,40,20);
    resetButton.setBounds(80,320,40,20);
    rightButton.setBounds(120,320,40,20);
    downButton.setBounds(80,340,40,20);
    resetButton.addActionListener(resetListener);
    plusButton.addActionListener(plusListener);
    minusButton.addActionListener(minusListener);
    upButton.addActionListener(upListener);
    downButton.addActionListener(downListener);
    leftButton.addActionListener(leftListener);
    rightButton.addActionListener(rightListener);
    cbg = new CheckboxGroup();
    singleCross = new Checkbox("Single Cross-section", cbg, true); add(singleCross);
    multiCross = new Checkbox("Many Cross-sections", cbg, false);  add(multiCross);
    approx = new Checkbox("Approximate Volume", cbg, false); 	 add(approx);
    singleCross.setBounds(30,140,150,20);
    singleCross.addItemListener(this);
    multiCross.setBounds(30,160,150,20);
    multiCross.addItemListener(this);
    approx.setBounds(30,180,150,20);
    approx.addItemListener(this);
  }

   public void itemStateChanged(ItemEvent e) {
   mainpanel.repaint();
    }

  public class CurvePanel extends Panel {
    public void paint(Graphics g){  
	g.setColor(Color.black);
     	g.drawRect(0,0,398,398); //box it
	for (int end=0; end<=1; end++){
	  if (end==0) shrink=1; else shrink=.4;
	  if (end==0) xend=10; else xend=-10;
	  for (int i=0; i<=10; i++) {t0 = i/10.;   //curve1
	    if (i>0) {x0=x1; y0=y1; z0=z1;}
	    x1=xend; y1=shrink*yt1(t0); z1=shrink*zt1(t0);
	    if (i>0) g.drawLine(xtran(x0,y0,z0),ytran(x0,y0,z0),xtran(x1,y1,z1),ytran(x1,y1,z1));		 
	  }
	  for (int i=0; i<=10; i++) {t0 = i/10.;   //curve2
	    if (i>0) {x0=x1; y0=y1; z0=z1;}
	    x1=xend; y1=shrink*yt2(t0); z1=shrink*zt2(t0);
	    if (i>0) g.drawLine(xtran(x0,y0,z0),ytran(x0,y0,z0),xtran(x1,y1,z1),ytran(x1,y1,z1));	
	  }
	  for (int i=0; i<=10; i++) {t0 = i/10.;    //curve3
	    if (i>0) {x0=x1; y0=y1; z0=z1;}
	    x1=xend; y1=shrink*yt3(t0); z1=shrink*zt3(t0);
	    if (i>0) g.drawLine(xtran(x0,y0,z0),ytran(x0,y0,z0),xtran(x1,y1,z1),ytran(x1,y1,z1));	
	  }
	  g.drawLine(xtran(-10,0,0),ytran(-10,0,0),xtran(13,0,0),ytran(13,0,0)); //leading edge?
	//  g.drawLine(xtran(-10,.4,0),ytran(-10,.4,0),xtran(10,1,0),ytran(10,1,0));
	  g.drawLine(xtran(-10,0,2),ytran(-10,0,2),xtran(10,0,5),ytran(10,0,5)); //trailing edge
	}
	if (singleCross.getSelectedObjects()!=null) {
	  shrink=(70+3*sliceLoc)/100.;
        g.setFont(new Font("Dialog",0,16));
        String s = "Area of slice = " + String.valueOf((int)(1000*shrink*shrink*2.5+.5)/1000.) + " sq.ft.";
        g.drawString(s,10,20);
	  g.setColor(Color.blue);
	  xend=sliceLoc;
	  for (int i=0; i<10; i++) {t0 = i/10.;   //curve1
	    x1=xend; y1=shrink*yt1(t0); z1=shrink*zt1(t0);
	    curvex[i]=xtran(x1,y1,z1);curvey[i]=ytran(x1,y1,z1);		 
	  }
	  for (int i=0; i<10; i++) {t0 = i/10.;   //curve2
	    x1=xend; y1=shrink*yt2(t0); z1=shrink*zt2(t0);
	    curvex[i+10]=xtran(x1,y1,z1); curvey[i+10]=ytran(x1,y1,z1);	
	  }
	  for (int i=0; i<10; i++) {t0 = i/10.;    //curve3
	    x1=xend; y1=shrink*yt3(t0); z1=shrink*zt3(t0);
	    curvex[i+20]=xtran(x1,y1,z1); curvey[i+20]=ytran(x1,y1,z1);	
	  }
	  g.fillPolygon(curvex,curvey,30); g.drawPolygon(curvex,curvey,30);
	}	
      if (multiCross.getSelectedObjects()!=null) {
aveArea=0;
	  sliceWidth = 20./(numSlices+1);
	  g.setColor(Color.red);
	  for (int j=1; j<=numSlices; j++){
	    xend=-10+j*sliceWidth;
	    shrink=(70+3*xend)/100.;
aveArea+=shrink*shrink*2.5;
	    for (int i=0; i<10; i++) {t0 = i/10.;   //curve1
	      x1=xend; y1=shrink*yt1(t0); z1=shrink*zt1(t0);
	      curvex[i]=xtran(x1,y1,z1);curvey[i]=ytran(x1,y1,z1);		 
	    }
	    for (int i=0; i<10; i++) {t0 = i/10.;   //curve2
	      x1=xend; y1=shrink*yt2(t0); z1=shrink*zt2(t0);
	      curvex[i+10]=xtran(x1,y1,z1); curvey[i+10]=ytran(x1,y1,z1);	
	    }
	    for (int i=0; i<10; i++) {t0 = i/10.;    //curve3
	      x1=xend; y1=shrink*yt3(t0); z1=shrink*zt3(t0);
	      curvex[i+20]=xtran(x1,y1,z1); curvey[i+20]=ytran(x1,y1,z1);	
	    }
	    g.fillPolygon(curvex,curvey,30); g.drawPolygon(curvex,curvey,30);
	  }
g.setColor(Color.black);
        g.setFont(new Font("Dialog",0,16));
        String s = "Ave. area of slices = " + String.valueOf((int)(1000*aveArea/numSlices+.5)/1000.) + " sq.ft.";
        g.drawString(s,10,20);
      }  
     if (approx.getSelectedObjects()!=null) {
	  slabWidth = 20./numSlabs; volume = 0.0;
	  g.setColor(Color.magenta);
	  slabWidth = 20./numSlabs;
	  for (int j=0; j<numSlabs; j++){
	    for (int side=0; side<=1; side++){
	      xend=-10+(j+side)*slabWidth; if (side==0) xend0=xend;
	      shrink=(70+3*(-10+(j+1)*slabWidth))/100.;  //outer volume, remove +1 for inner
if (side==0) volume=volume+slabWidth*2.5*shrink*shrink;
	      for (int i=0; i<10; i++) {t0 = i/10.;   //curve1
	        x1=xend; y1=shrink*yt1(t0); z1=shrink*zt1(t0);
	        curvex[i]=xtran(x1,y1,z1);curvey[i]=ytran(x1,y1,z1);		 
	      }
	      for (int i=0; i<10; i++) {t0 = i/10.;   //curve2
	        x1=xend; y1=shrink*yt2(t0); z1=shrink*zt2(t0);
	        curvex[i+10]=xtran(x1,y1,z1); curvey[i+10]=ytran(x1,y1,z1);	
	      }
	      for (int i=0; i<10; i++) {t0 = i/10.;    //curve3
	        x1=xend; y1=shrink*yt3(t0); z1=shrink*zt3(t0);
	        curvex[i+20]=xtran(x1,y1,z1); curvey[i+20]=ytran(x1,y1,z1);	
	      }
	      g.drawPolygon(curvex,curvey,30);
	    }
 	    g.drawLine(xtran(xend,0,0),ytran(xend,0,0),xtran(xend0,0,0),ytran(xend0,0,0)); //leading edge?
//	    g.drawLine(xtran(xend,shrink,0),ytran(xend,shrink,0),xtran(xend0,shrink,0),ytran(xend0,shrink,0));
          g.drawLine(xtran(xend,0,5*shrink),ytran(xend,0,5*shrink),xtran(xend0,0,5*shrink),ytran(xend0,0,5*shrink)); //trailing edge
	    }
        g.setFont(new Font("Dialog",0,16));
	  g.setColor(Color.black);
        g.drawString("Volume of slabs = " + String.valueOf((int)(1000*volume+.5)/1000.) + " cu.ft.",10,20);
	}	
    }
  }
}