//
//     サイン波の合成
//
//  2000/11/13 宍戸　輝光
//

import java.awt.*;
import java.awt.event.*;

class CSinDisp extends Canvas { // 表示パネルクラス

	double pi=Math.PI;
	private int width,height;
	double a1,b1,a2,b2;
	Image img;
	Graphics g_img;

	CSinDisp(int w,int h) {

		width=w;
		height=h;

		setA1(1);
		setB1(1);
		setA2(0);
		setB2(0);

		setSize(width+2,height+2);

	}

	public void setA1(double w) { a1=w; }
	public void setB1(double w) { b1=w; }
	public void setA2(double w) { a2=w; }
	public void setB2(double w) { b2=w; }

	private void draw() { // 現在の状況を描画

		double dx=2*pi/(double)width,dy=(double)height/8.0;
		int y1,y2;

		g_img.setColor(Color.blue);
		g_img.fillRect(0,0,width,width);
		g_img.setColor(Color.gray);
		g_img.drawLine(0,height/2,width,height/2);
		g_img.setColor(Color.white);

		y1=height-((int)Math.sin(0)+height/2);

		for (int i=1;i<width;i++) {

			y2=(int)(getVal(i*dx)*dy);
			y2=height-(y2+height/2);
			g_img.drawLine(i,y1,i,y2);

			y1=y2;

		}

	}

	public void paint(Graphics g) {

		if (img==null) { // 最初の描画時にイメージ作成

			img=createImage(width,height);
			g_img=img.getGraphics();

		}

		draw(); // 現在の状況をイメージに描画

		g.drawImage(img,1,1,this);

	}

	private double getVal(double x) {

		double res;

		res=a1*Math.sin(b1*x);
		res+=a2*Math.sin(b2*x);

		return res;

	}

}

public class coss extends java.applet.Applet implements ActionListener {

	CSinDisp dp1,dp2,dp3;
	TextField fa1,fa2,fb2,fb1;
	Button btGo;
	Panel s1,s2,s3,l1,l2,l3;
	Label sinl;
	double a1,a2,b1,b2;

	public void init() {

		fa1=new TextField(3);
		fb1=new TextField(3);
		l1=new Panel();
		l1.add(new Label("y="));
		l1.add(fa1);
		l1.add(new Label("sin"));
		l1.add(fb1);
		l1.add(new Label("x"));
		dp1=new CSinDisp(300,120);
		s1=new Panel();
		s1.setLayout(new BorderLayout());
		s1.add("Center",dp1);
		s1.add("South",l1);

		fa2=new TextField(3);
		fb2=new TextField(3);
		l2=new Panel();
		l2.add(new Label("y="));
		l2.add(fa2);
		l2.add(new Label("sin"));
		l2.add(fb2);
		l2.add(new Label("x"));
		dp2=new CSinDisp(300,120);
		s2=new Panel();
		s2.setLayout(new BorderLayout());
		s2.add("Center",dp2);
		s2.add("South",l2);

		l3=new Panel();
		sinl=new Label("4sinx+sin2x");
		dp3=new CSinDisp(300,120);
		btGo=new Button("Go");
		btGo.addActionListener(this);
		l3.add(sinl);
		l3.add(btGo);
		s3=new Panel();
		s3.setLayout(new BorderLayout());
		s3.add("Center",dp3);
		s3.add("South",l3);

		fa1.setText("3");
		fa2.setText("1");
		fb1.setText("1");
		fb2.setText("4");

		drawData();

		add(s1);
		add(s2);
		add(s3);

	}

	public void actionPerformed(ActionEvent e) {

		if (e.getSource()==btGo) { // Nextボタン

			drawData();

		}

	}

	private void drawData() {

		double ba1,ba2,bb1,bb2;

		try {

			ba1=Double.valueOf(fa1.getText()).doubleValue();
			ba2=Double.valueOf(fa2.getText()).doubleValue();
			bb1=Double.valueOf(fb1.getText()).doubleValue();
			bb2=Double.valueOf(fb2.getText()).doubleValue();

		} catch (Exception e){

			ba1=a1;
			ba2=a2;
			bb1=b1;
			bb2=b2;

			fa1.setText(String.valueOf(a1));
			fa2.setText(String.valueOf(a2));
			fb1.setText(String.valueOf(b1));
			fb2.setText(String.valueOf(b2));

		}

		a1=ba1;
		a2=ba2;
		b1=bb1;
		b2=bb2;

		dp1.setA1(a1);
		dp1.setB1(b1);
		dp2.setA1(a2);
		dp2.setB1(b2);
		dp3.setA1(a1);
		dp3.setB1(b1);
		dp3.setA2(a2);
		dp3.setB2(b2);

		String str=String.valueOf(a1)+"sin";
		str+=String.valueOf(b1)+"x+";
		str+=String.valueOf(a2)+"sin";
		str+=String.valueOf(b2)+"x";
		sinl.setText(str);

		dp1.repaint();
		dp2.repaint();
		dp3.repaint();

	}

}