package fft;

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

/**
 * <p>タイトル: </p>
 * <p>説明: </p>
 * <p>著作権: Copyright (c) 2003</p>
 * <p>会社名: </p>
 * @author 未入力
 * @version 1.0
 */

public class Applet1 extends Applet
    implements ItemListener, AdjustmentListener {

  private boolean isStandalone = false;
  private Scrollbar scr1, scr2, scr3, scr4;
  private CheckboxGroup cgC;
  private Checkbox [] cbCh;
  private CheckboxGroup cgD;
  private Checkbox cboxO, cboxF;
  private Choice w_choice, s_choice;

  //引数値の取得
  public String getParameter(String key, String def) {
    return isStandalone ? System.getProperty(key, def) :
      (getParameter(key) != null ? getParameter(key) : def);
  }

  //アプレットのビルド
  public Applet1() {
  }
  //アプレットの初期化
  public void init() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
    finit();
  }
  //コンポーネントの初期化
  private void jbInit() throws Exception {
  }
  //アプレットの情報取得
  public String getAppletInfo() {
    return "アプレット情報";
  }
  //引数情報の取得
  public String[][] getParameterInfo() {
    return null;
  }

  int n = 10;                   // 2^n
  int N = (int)Math.pow(2,n);  // Scale
  int FO = 2;                  // 1-fft 2-osc
  int Csw = 2;                 // 0-ch1 1-ch2 2-add
  int Wsw = 0;                 // 0-sin 1-square 2-harp 3-piano
  int SP;                      // striking point
  double L = 40.0;             // string length
  double Psl;                  // Math.PI*SP/L
  double Z;

  double [] sin_tbl;
  double [] cos_tbl;
  double [] b_re;
  double [] b_im;
  double [] re;
  double [] im;
  double [] dat;
  final String [] Wave = {"Saw","Square"};
  final String [] Samp = {"8","9","10","11"};
  final String [] Chan = {"Ch1","Ch2","Add"};

  public void finit() {
    setFont(new Font("SansSerif", Font.PLAIN, 12));
    setBackground(Color.lightGray);
    setLayout(new BorderLayout());

    Panel p = new Panel();
    Panel q = new Panel();
    p.setLayout(new GridLayout(2,4,0,0));
    q.setLayout(new FlowLayout());

    scr3 = new Scrollbar(Scrollbar.HORIZONTAL,1,2,1,10);    // partial
    p.add(scr3);
    p.add(new Label("Partial"));
    scr3.setBlockIncrement(2);
    scr3.addAdjustmentListener(this);

    scr1 = new Scrollbar(Scrollbar.HORIZONTAL,10,10,0,100); // Ch1
    p.add(scr1);
    p.add(new Label("Ch 1"));
    scr1.setBlockIncrement(10);
    scr1.addAdjustmentListener(this);

    scr4 = new Scrollbar(Scrollbar.HORIZONTAL,4,1,0,11);    // volume
    p.add(scr4);
    p.add(new Label("Level"));
    scr4.setBlockIncrement(2);
    scr4.addAdjustmentListener(this);

    scr2 = new Scrollbar(Scrollbar.HORIZONTAL,20,10,0,100); // Ch2
    p.add(scr2);
    p.add(new Label("Ch 2"));
    scr2.setBlockIncrement(10);
    scr2.addAdjustmentListener(this);

    cgC = new CheckboxGroup();
    cbCh = new Checkbox[Chan.length];
    for (int i = 0; i < Chan.length; i++) {
      boolean sw = (i == 2) ? true : false;
      cbCh[i] = new Checkbox(Chan[i], sw, cgC);
      q.add(cbCh[i]);
      cbCh[i].addItemListener(this);
    }
    //データ数選択メニュー
    s_choice = new Choice();
    for (int i = 0; i < Samp.length; i++) {
      s_choice.addItem(Samp[i]);
    }
    q.add(s_choice);
    s_choice.select(2);
    s_choice.addItemListener(this);

    cgD = new CheckboxGroup();
    cboxO = new Checkbox("OSC", true, cgD);
    cboxF = new Checkbox("FFT", false, cgD);
    q.add(cboxO);
    q.add(cboxF);
    cboxO.addItemListener(this);
    cboxF.addItemListener(this);

    //波形メニュー
    w_choice = new Choice();
    for (int i = 0; i < Wave.length; i++) {
      w_choice.addItem(Wave[i]);
    }
    q.add(w_choice);
    w_choice.addItemListener(this);

    add(p,"South");
    add(q,"North");
  }

 public void start() {
  ini();
 }

 public void adjustmentValueChanged(AdjustmentEvent e) {
repaint();
 }

//ボタン切り替え処理
 public void itemStateChanged(ItemEvent e) {
   if (cboxF.getState())      // osc/fft切り替え
     FO = 1;
   else if (cboxO.getState())
     FO = 2;

   for (int i = 0; i < Chan.length; i++) {    // ch1/2/add切り替え
     if (cbCh[i].getState() )
       Csw = i;
   }

   if (e.getSource() == s_choice) {      // 8/9/10/11　データ数
     String st = s_choice.getSelectedItem();
     n = Integer.parseInt(st);
     N = (int)Math.pow(2,n);
   }

   if (e.getSource() == w_choice) {    // sin/square？？
     Wsw = w_choice.getSelectedIndex();
   }

repaint();
 }

//波形データの生成
 private double sinq(double f, int p) {
  if (Wsw == 0) {                          // sin wave
   return(Math.sin(p*f)/(p*Math.PI));
  } else if (Wsw == 1) {    // square wave　倍音を加えて合成
   p--;
   return((1.0/Math.PI)*Math.sin((2*p+1)*f )/(2*p+1));
  } else if (Wsw == 2) {                   // harp
   return(Math.sin(p*f)*
    Math.abs(Z*Math.sin(p*Psl)/Math.pow(p*Math.PI,2)));
  } else {                                 // piano
   return(Math.sin(p*f)*
    Math.abs(2*Math.sin(p*Psl)/(p*Math.PI)));
  }
 }

 public void update(Graphics g) {
   paint(g);
 }

 public void paint(Graphics g) {

   int sw = getSize().width;
   int sh = getSize().height;
   int hw = sw/2;
   int hh = sh/2;
   double xd = sw*2.0/N;
   int s0 = sh-100;
   int m1;

   int baion = scr3.getValue();
   int scale = scr4.getValue();
   int f1 = scr1.getValue();
   int f2 = scr2.getValue();
   //SP = scr5.getValue();
   SP=0;
   Z = Math.pow(L, 2)/(double)(SP*(L-SP));//Lは弦の長さ

   ini();//関数表、FFt配列

   g.setColor(Color.black);
   g.fillRect(0, 0, sw, sh);

   double xi = 2.0*Math.PI/(double)N;
   Psl = Math.PI*SP/L;
   for (int i = 0; i < N; i++){
     double x1 = xi*i;
     for (int p = 1; p <= baion; p++) {
       if (Csw == 0) {                // ch1
         re[i] += sinq(f1*x1, p);//ch1の波形配列のi番目の値（倍音p)
       }
       else if (Csw == 1) {           // ch2
         re[i] += sinq(f2*x1, p);
       }
       else {                         // add
         re[i] += (sinq(f1*x1, p) + sinq(f2*x1, p));
       }
     }
     im[i] = re[i];
   }

   switch(FO) {
     case 1:              //-------- fft
       double mxd = scale*10.0;
       int s1 = 2;

       fft_main();                 //
       fft_bit();                  //
       fft_amp();                  //

       g.setColor(Color.gray);
       g.drawLine(0, s0+s1, sw, s0+s1);

       int sx = s0/12;
       for (int i = 0; i < 12; i++) {
         int sxi = s0-sx*i;
         g.setColor(Color.blue);
         g.drawLine(0, sxi, sw-1, sxi);

         g.setColor(Color.pink);
         g.drawString(i+"", sw-18, sxi);
       }

       for (int i = 0; i < N/2; i++) {
         int ixd = (int)(i * xd);
         //目盛りの表示
         g.setColor(Color.orange);
         m1 = (i%10 == 0) ? 5 : 2;
         if(i %50==0) m1=10;
         g.drawLine(ixd, s0+m1, ixd, s0+s1);
         //FFTの値を表示
         g.setColor(Color.green);
         g.drawLine(ixd, s0-(int)(dat[i]*mxd), ixd, s0);
       }

       g.setColor(Color.yellow);
       g.drawString("Max:"+N/2+"[Hz]",sw-86, s0+22);

       break;

     case 2:                        //-------- osc
       double hd = sw/(double)N;

       g.setColor(new Color(0,0,170));       // lines
       int wn = 20;
       for (int i = 1; i < wn; i++) {
         int siw = sh*i/wn;
         g.drawLine(0, siw, sw, siw);
       }
       for (int j = 1; j < wn; j++) {
         int sjw = sw*j/wn;
         g.drawLine(sjw, 0, sjw, sh);
       }

       double y0 = 0, y1;
       double x0 = 0, x1;
       g.setColor(Color.green);
       for (int x = 0; x < N; x++) {
         y1 = re[x]*scale*20.0;
         x1 = x*hd;
         g.drawLine((int)x0, hh-(int)y0, (int)x1, hh-(int)y1);
         y0 = y1;
         x0 = x1;
       }

       break;
   }
   int s3 = 48;
   g.setColor(Color.red);
   g.drawString("Ch1:"+f1+"/Ch2:"+f2, 5, s3);
   g.drawString("Partial:"+baion, hw-86, s3);
   g.drawString("Strik-p:"+SP+"/"+L+"="+SP/L, hw-18, s3);
   g.drawString("Level:"+scale, sw-80, s3);

   //g.setColor(Color.white);
   //g.drawString("F F T - S I M U L A T O R v1.5", hw-90, s0+28);
 }

 public void ini() {
   //関数表、fft領域確保
   sin_tbl = new double[N];
   cos_tbl = new double[N];
   b_re = new double[N];
   b_im = new double[N];
   re = new double[N];
   im = new double[N];
   dat = new double [N];

   double xx = -Math.PI*2.0/(double)N;
   double arg;
   for (int i = 0; i < N; i++) {
     arg = i * xx;
     sin_tbl[i] = Math.sin(arg);
     cos_tbl[i] = Math.cos(arg);
   }
 }

 public void fft_main() {
   int num = 1;
   int len = N;
   int tim, w, j1, j2;
   double xr, xi, yr, yi;

   for (int i = 0; i < n; i++) {
     len = len/2;
     tim = 0;
     for (int j = 0; j < num; j++) {
       w = 0;
       for (int k = 0; k < len; k++) {
         j1 = tim + k;
         j2 = j1 + len;
         xr = re[j1];
         xi = im[j1];
         yr = re[j2];
         yi = im[j2];
         re[j1] = xr + yr;
         im[j1] = xi + yi;
         xr = xr - yr;
         xi = xi - yi;
         re[j2] = xr * cos_tbl[w] - xi * sin_tbl[w];
         im[j2] = xr * sin_tbl[w] + xi * cos_tbl[w];
         w = w + num;
       }
       tim = tim + 2 * len;
     }
     num = num * 2;
   }
 }

 public void fft_bit() {
   int ii, k, bit;

   for (int i = 0; i < N; i++) {
     for (k = 0,ii = i, bit = 0; ; bit<<=1, ii>>=1) {
       bit = (ii & 1) | bit;
       if (++k == n) break;
     }
     b_re[i] = re[bit];
     b_im[i] = im[bit];
   }
   for (int i = 0; i < N; i++) {
     re[i] = b_re[i];
     im[i] = b_im[i];
   }
   double nrml = 1.0/Math.sqrt(N);
   for (int i = 0; i < N; i++) {
     re[i] = re[i] * nrml;
     im[i] = im[i] * nrml;
   }
 }

 public void fft_amp() {
   for (int i = 0; i < N/2; i++) {
     dat[i] = Math.sqrt( re[i] * re[i] + im[i] * im[i]);
   }
 }


}//class