//
//  trigdial.java
//  trigdial
//
//  This is a simple Java applet to help see how the six trig functions
//  can be found for obtuse angles by showing the graph and
//  the reference tringle inside a unit circle.  Click 
//  (or click and drag) either on the graph or the circle
//  to see the lengths of the reference triangle and the
//  value of the trig function.
//
//
//  Created by Chris Thiel on 1/9/05.
//  Copyright (c) 2005 Chris Thiel. All rights reserved.
//  Free to use or change for educational purposes, with proper
//  citation.   You shouldn't charge people money for
//  this otherwise free applet.  Questions, or comments?
//  email me at cct@ktb.net
//  or see latest e-mail at www.mathorama.com
//  
//  31 Aug 2010 Added Graphics Buffer for better look on Windoze
//              Changed Layout to non null for Java 6




import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import java.lang.*;

public class trigdial extends Applet implements MouseMotionListener, MouseListener,ItemListener {

    String message = "0";
    private Font font = new Font("serif", Font.ITALIC, 18);
	//global variables:
	static final int x0= 450;
	static final int y0= 200;	// coords of origin
	static final int r= 100;		// radius length
    int x1,y1;					// point location
	int dx,dy;					// distance of point to origin
	int r2=r*r;					// radius squared
	double t;					// angle
	int xOffset, yOffset;
	Choice daMenu;
	private String[] fName = new String[6]; // names of the 6 functions
	int d; //dist from drag to circle ..make local later
	Image virtualMem;
    Graphics gBuffer;
	
	
	public void init() {
		int i;
        setLayout (new FlowLayout());
		this.setBackground(new Color(0xF0FFFF));
		addMouseMotionListener(this);
		addMouseListener(this);
		
		x1 = x0+r;
		y1 = y0;
		daMenu = new Choice();
		fName[0]="sin";
		fName[1]="cos";
		fName[2]="tan";
		fName[3]="csc";
		fName[4]="sec";
		fName[5]="cot";
		for (i=0; i<6; i++) daMenu.addItem(fName[i]);
		add(daMenu);
		daMenu.addItemListener(this);
		virtualMem = createImage(getWidth(),getHeight());
        gBuffer = virtualMem.getGraphics();
        gBuffer.setColor(Color.white);
        gBuffer.fillRect(0,0,getWidth(),getHeight());

    }
	
	 
	//  PAINT STUFF
    public void paint (Graphics g) {
        virtualMem = createImage(getWidth(),getHeight());
        gBuffer = virtualMem.getGraphics();
        gBuffer.setColor(Color.white);
        gBuffer.fillRect(0,0,getWidth(),getHeight());
        gBuffer.setColor(Color.magenta);
        gBuffer.setFont(font);
       // gBuffer.drawString(message, 40, 80);
		
		gBuffer.drawString("\u03b8 = "+(t/Math.PI)+" \u03c0 radians",250,50); // \u03c0 is the Pi symbol
		gBuffer.drawString("or "+(t*180/Math.PI)+"\u00b0",250,73); // \u00b0 is the Degree symbol
	
		gBuffer.setColor(Color.red);
		gBuffer.drawString("x (adj) = "+((x1-x0)/100.0), 250, 100);
		gBuffer.setColor(Color.blue);
		gBuffer.drawString("y (opp) = "+((y0-y1)/100.0), 250, 120);
		gBuffer.setColor(Color.magenta);
        gBuffer.fillOval(x1-5,y1-5,10,10);
		gBuffer.drawArc(x0-r/4,y0-r/4,r/2,r/2,0,(int)(180*t/Math.PI));
		gBuffer.setColor(Color.blue);
		gBuffer.drawLine (x1,y1,x1,y0);
		
		
		
		gBuffer.setColor(Color.black);
		gBuffer.drawLine (x1,y1,x0,y0);
		gBuffer.drawOval(x0-r,y0-r,2*r,2*r);
		gBuffer.drawLine( x0-r-20, y0, x0+r+20, y0);
		gBuffer.drawLine( x0, y0-r-20, x0, y0+r+20);
		
		gBuffer.drawLine( 20, y0, 230, y0);
		gBuffer.drawLine( 20, y0-r-20, 20, y0+r+20);
		gBuffer.drawLine( x0-r-20, y0, x0+r+20, y0);
		
		gBuffer.setFont(new Font("serif",  Font.BOLD, 12));
		gBuffer.drawLine( x0, y0-r-20, x0, y0+r+20);
		gBuffer.drawString("1", 10,y0-r);
		gBuffer.drawString("0", 10, y0);
		gBuffer.drawString("-1",10,y0+r);
		gBuffer.drawString("\u03c0", 65,y0+12);
		gBuffer.drawString("__", 62,y0+11);
		gBuffer.drawString("2", 65,y0+24);
		gBuffer.drawString("\u03c0", 115,y0+12);
		gBuffer.drawString("3\u03c0", 165,y0+12);
		gBuffer.drawString("__", 163,y0+11);
		gBuffer.drawString("2", 167,y0+24);
		gBuffer.drawString("2\u03c0", 215,y0+12);
		
		gBuffer.setFont(new Font("serif",  Font.BOLD, 14));

		switch (daMenu.getSelectedIndex() ){
		//sin
		case(0):{
		for(double j=0.0;j<23.0*Math.PI/12.0;j=j+Math.PI/12.0){
			gBuffer.drawLine(20+(int)(j*100.0/Math.PI), y0-(int)(Math.sin(j)*r), 
			20+(int)((j+Math.PI/12.0)*100.0/Math.PI), y0-(int)(Math.sin((j+Math.PI/12.0))*r));
			}
			gBuffer.setColor(Color.BLUE);
		gBuffer.fillOval(20+(int)(t*100.0/Math.PI)-4, y0-(int)(Math.sin(t)*r)-4,8,8);
		gBuffer.setColor(Color.BLACK);
		gBuffer.drawString("sin \u03b8 =   ------   =  "+ ((int)(10000*Math.sin(t))/10000.0), 235, 370);
		gBuffer.setColor(Color.blue);
		gBuffer.drawString( ((y0-y1)/100.0)+" ", 290,360);
		gBuffer.setColor(Color.black);
		gBuffer.drawString("   1", 290,380);         

		
		if(y1-y0 > 0) yOffset=10; else yOffset=-10;
		if(x1-x0 > 0) xOffset=10; else xOffset=-70; 
		gBuffer.drawString("("+((x1-x0)/100.0)+","+((y0-y1)/100.0)+")", x1+xOffset,y1+yOffset);
		gBuffer.drawString(" 1", x0+((x1-x0)/2), y0+((y1-y0)/2)+yOffset);
		}
		break; //end of sin
		//cos
		case(1):{
		for(double j=0.0;j<23.0*Math.PI/12.0;j=j+Math.PI/12.0){
			gBuffer.drawLine(20+(int)(j*100.0/Math.PI), y0-(int)(Math.cos(j)*r), 
			20+(int)((j+Math.PI/12.0)*100.0/Math.PI), y0-(int)(Math.cos((j+Math.PI/12.0))*r));
			}
		gBuffer.setColor(Color.BLUE);
		gBuffer.fillOval(20+(int)(t*100.0/Math.PI)-4, y0-(int)(Math.cos(t)*r)-4,8,8);
		gBuffer.setColor(Color.BLACK);
		gBuffer.drawString("cos \u03b8 =   ------   =  "+ ((int)(10000*Math.cos(t))/10000.0), 235, 370);
		gBuffer.setColor(Color.red);
		gBuffer.drawString( ((x1-x0)/100.0)+" ", 290,360);
		gBuffer.setColor(Color.black);
		gBuffer.drawString("   1", 290,380);         
		
		
		if(y1-y0 > 0) yOffset=10; else yOffset=-10;
		if(x1-x0 > 0) xOffset=10; else xOffset=-70; 
		gBuffer.drawString("("+((x1-x0)/100.0)+","+((y0-y1)/100.0)+")", x1+xOffset,y1+yOffset);
		gBuffer.drawString(" 1", x0+((x1-x0)/2), y0+((y1-y0)/2)+yOffset);
		}
		break; //end of cos
		
		//tan
		case(2):{
		for(double j=-1*Math.PI/13.0;j<24.0*Math.PI/12.0;j=j+Math.PI/12.0){
			gBuffer.drawLine(20+(int)(j*100.0/Math.PI), y0-(int)(Math.tan(j)*r), 
			20+(int)((j+Math.PI/12.0)*100.0/Math.PI), y0-(int)(Math.tan((j+Math.PI/12.0))*r));
			}
		gBuffer.setColor(Color.BLUE);	
		gBuffer.fillOval(20+(int)(t*100.0/Math.PI)-4, y0-(int)(Math.tan(t)*r)-4,8,8);
		gBuffer.setColor(Color.black);
		if (x0-x1==0){gBuffer.drawString("tan \u03b8 =   ------   =  undefined", 235, 370);}
			else{ gBuffer.drawString("tan \u03b8 =   ------   =  "+ ((int)(10000*Math.tan(t))/10000.0), 235, 370);}
		gBuffer.setColor(Color.blue);
		gBuffer.drawString( ((y0-y1)/100.0)+" ", 290,360);
		gBuffer.setColor(Color.red);
		gBuffer.drawString( ((x1-x0)/100.0)+" ", 290,380);         
		
		gBuffer.setColor(Color.black);
		if(y1-y0 > 0) yOffset=10; else yOffset=-10;
		if(x1-x0 > 0) xOffset=10; else xOffset=-70; 
		gBuffer.drawString("("+((x1-x0)/100.0)+","+((y0-y1)/100.0)+")", x1+xOffset,y1+yOffset);
		gBuffer.drawString(" 1", x0+((x1-x0)/2), y0+((y1-y0)/2)+yOffset);
		}
		break; //end of tan
		//csc
		case(3):{
		for(double j=Math.PI/13.0;j<24.0*Math.PI/12.0;j=j+Math.PI/12.0){
			gBuffer.drawLine(20+(int)(j*100.0/Math.PI), y0-(int)(r/(Math.sin(j))), 
			20+(int)((j+Math.PI/12.0)*100.0/Math.PI), y0-(int)(r/Math.sin((j+Math.PI/12.0))));
			}
		gBuffer.setColor(Color.BLUE);
		gBuffer.fillOval(20+(int)(t*100.0/Math.PI)-4, y0-(int)(r/Math.sin(t))-4,8,8);
		gBuffer.setColor(Color.BLACK);
		if(y1-y0==0){gBuffer.drawString("csc \u03b8 = ------  = undefined", 235,370 );}
			else {gBuffer.drawString("csc \u03b8 =   ------   =  "+ (1.0/Math.sin(t)), 235, 370);}
		gBuffer.setColor(Color.blue);
		gBuffer.drawString( ((y0-y1)/100.0)+" ", 290,380);
		gBuffer.setColor(Color.black);
		gBuffer.drawString("   1", 290,360);         
		
		
		if(y1-y0 > 0) yOffset=10; else yOffset=-10;
		if(x1-x0 > 0) xOffset=10; else xOffset=-70; 
		gBuffer.drawString("("+((x1-x0)/100.0)+","+((y0-y1)/100.0)+")", x1+xOffset,y1+yOffset);
		gBuffer.drawString(" 1", x0+((x1-x0)/2), y0+((y1-y0)/2)+yOffset);
		}
		break; //end of csc
		
		//sec
		case(4):{
		for(double j=0.0;j<25.0*Math.PI/13.0;j=j+Math.PI/13.0){
			gBuffer.drawLine(20+(int)(j*100.0/Math.PI), y0-(int)(r/Math.cos(j)), 
			20+(int)((j+Math.PI/13.0)*100.0/Math.PI), y0-(int)(r/Math.cos((j+Math.PI/13.0))));
			}
		gBuffer.setColor(Color.BLUE);
		gBuffer.fillOval(20+(int)(t*100.0/Math.PI)-4, y0-(int)(r/Math.cos(t))-4,8,8);
		gBuffer.setColor(Color.BLACK);if(x0-x1==0) {gBuffer.drawString("sec \u03b8 =   ------   =  undefined", 235, 370);}
				else {gBuffer.drawString("sec \u03b8 =   ------   =  "+ (1.0/Math.cos(t)), 235, 370);}
		gBuffer.setColor(Color.red);
		gBuffer.drawString( ((x1-x0)/100.0)+" ", 290,380);
		gBuffer.setColor(Color.black);
		gBuffer.drawString("   1", 290,360);         
		
		
		if(y1-y0 > 0) yOffset=10; else yOffset=-10;
		if(x1-x0 > 0) xOffset=10; else xOffset=-70; 
		gBuffer.drawString("("+((x1-x0)/100.0)+","+((y0-y1)/100.0)+")", x1+xOffset,y1+yOffset);
		gBuffer.drawString(" 1", x0+((x1-x0)/2), y0+((y1-y0)/2)+yOffset);
		}
		break; //end of sec
		
		//cot
		case(5):{
		for(double j=Math.PI/13.0;j<25.0*Math.PI/12.0;j=j+Math.PI/12.0){
			gBuffer.drawLine(20+(int)(j*100.0/Math.PI), y0-(int)(r/Math.tan(j)), 
			20+(int)((j+Math.PI/12.0)*100.0/Math.PI), y0-(int)(r/Math.tan((j+Math.PI/12.0))));
			}
		gBuffer.setColor(Color.BLUE);
		gBuffer.fillOval(20+(int)(t*100.0/Math.PI)-4, y0-(int)(r/Math.tan(t))-4,8,8);
		gBuffer.setColor(Color.BLACK);
		if (y0-y1==0){gBuffer.drawString("cot \u03b8 =   ------   =  undefined", 235, 370);}
			else{ gBuffer.drawString("cot \u03b8 =   ------   =  "+ (int)(10000*(1/Math.tan(t)))/10000.0, 235, 370);}
		gBuffer.setColor(Color.blue);
		gBuffer.drawString( ((y0-y1)/100.0)+" ", 290,380);
		gBuffer.setColor(Color.red);
		gBuffer.drawString( ((x1-x0)/100.0)+" ", 290,360);         
		
		gBuffer.setColor(Color.black);
		if(y1-y0 > 0) yOffset=10; else yOffset=-10;
		if(x1-x0 > 0) xOffset=10; else xOffset=-70; 
		gBuffer.drawString("("+((x1-x0)/100.0)+","+((y0-y1)/100.0)+")", x1+xOffset,y1+yOffset);
		gBuffer.drawString(" 1", x0+((x1-x0)/2), y0+((y1-y0)/2)+yOffset);
		}
		break; //end of cot

		}//end of switch
		gBuffer.setColor(Color.red);
		gBuffer.drawLine (x1,y0,x0,y0);
		
		//Now we send the result to the screen
        g.drawImage(virtualMem,0,0,this);
    }

	//  MOUSE MOTION LISTENER STUFF
	private void updateByCircle(int mx, int my){
		d = (int)(Math.sqrt(dx*dx+dy*dy) - r); // (how close drag is to circle)
		dx = mx-x0;
		dy = y0-my; // (vertical screen coords are reversed from the cartesian coord system)
	
		t=Math.acos(dx/Math.sqrt(dx*dx+dy*dy)); // this way results are from 0 to Pi
		if (dy<0) t=2*Math.PI-t; // adjustment for the computer's trig function, since it expects 0-Pi
		x1=x0+(int)(r*Math.cos(t));
		y1=y0+(int)(-1*r*Math.sin(t));
		
	}
	private void updateByGraph(int mx){
		t=Math.PI*(mx-20)/100.0;
		x1=x0+(int)(r*Math.cos(t));
		y1=y0+(int)(-1*r*Math.sin(t));
	}
	
	public void mouseMoved(MouseEvent e) {}
    public void mouseDragged(MouseEvent e) {
		int mx=e.getX();
		int my=e.getY();
		if (mx > 250) {updateByCircle(mx,my);}
		if (mx > 19 && mx<221){updateByGraph(mx);}
		repaint();
	}
	// MOUSE LISTENER STUFF
	public void mouseClicked(MouseEvent e) {
		int mx=e.getX();
		int my=e.getY();
		if (mx > 250) {updateByCircle(mx,my);}
		if (mx > 19 && mx<221){updateByGraph(mx);}
		
		repaint();
	}
	public void mouseEntered(MouseEvent e) {}
	public void mouseExited(MouseEvent e) {}
	public void mousePressed(MouseEvent e) {}
	public void mouseReleased(MouseEvent e) {}
	
	public void itemStateChanged(ItemEvent e) { repaint();} //redraw if the trig function was changed
}