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) 2004</p>
 * <p>会社名: </p>
 * @author 未入力
 * @version 1.0
 */

public class Applet1 extends Applet {
  private boolean isStandalone = false;

  int[] spx=new int[800];
  int[] spy=new int[800];

  int px[]={30,60,150,200,250};
  int py[]={200,80,50,220,50};
  int nump=0;
  int tmax;
  int match=-1;
  int [] nv1 = {0,1,2,3,4,5,6,7};
  int [] nv2 = {0,0,0,1,2,3,3,3};
  int [] nv = {1,2,3,4,5,6,7,8};

  boolean funcview=false,curvview=false;

  boolean profile=false;

  private Button button1 = new Button();
  private Button button2 = new Button();
  private Checkbox checkbox1 = new Checkbox();
  private Checkbox checkbox2 = new Checkbox();
  private CheckboxGroup checkboxGroup1 = new CheckboxGroup();
  //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();
    }
  }
  //コンポーネントの初期化
  private void jbInit() throws Exception {
    button1.setLabel("基底関数");
    button1.setBounds(new Rectangle(16, 254, 71, 27));
    button1.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button1_actionPerformed(e);
      }
    });
    this.setLayout(null);
    button2.setLabel("曲線");
    button2.setBounds(new Rectangle(108, 255, 57, 26));
    button2.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button2_actionPerformed(e);
      }
    });
    this.addMouseListener(new java.awt.event.MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        this_mousePressed(e);
      }
    });
    this.addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
      public void mouseDragged(MouseEvent e) {
        this_mouseDragged(e);
      }
    });
    this.addKeyListener(new java.awt.event.KeyAdapter() {
      public void keyReleased(KeyEvent e) {
        this_keyReleased(e);
      }
    });
    checkbox1.setCheckboxGroup(checkboxGroup1);
    checkbox1.setLabel("[1,2,3,4,5,6,7]");
    checkbox1.setBounds(new Rectangle(198, 245, 96, 18));
    checkbox2.setCheckboxGroup(checkboxGroup1);
    checkbox2.setLabel("[0,0,0,1,2,3,3,3]");
    checkbox2.setState(true);
    checkbox2.setBounds(new Rectangle(198, 268, 104, 21));
    this.add(button1, null);
    this.add(button2, null);
    this.add(checkbox1, null);
    this.add(checkbox2, null);
  }
  //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;
  }

  public void paint(Graphics g){

    if(profile){//制御点多角形を表示
      g.setColor(new Color(150,150,250));
      for(int i=0;i<5;i++){
        if(i>0)g.drawLine(px[i-1],py[i-1],px[i],py[i]);
        g.drawRect(px[i]-3,py[i]-3,5,5);
      }
    }

    g.setColor(Color.BLACK);
    for(int i=1;i<nump;i++){
      if((i %(tmax*10+1)) ==0) continue;
      if(!funcview && ((tmax==7)&&((i>20)&&(i<50))||tmax==3)||funcview){
      g.drawLine(spx[i-1],spy[i-1],spx[i],spy[i]);
    }
    }
  }

  double baseN(int i,int k,double t,int nv[]){
    double w1=0.0,w2=0.0;
    if(k==1){
      if(t >=nv[i] && t<nv[i+1]) return 1.0;
      else return 0.0;
    }
    else {
      if((nv[i+k]-nv[i+1])!=0){
        w1=((nv[i+k]-t)/(nv[i+k]-nv[i+1])) * baseN(i+1,k-1,t,nv);
        //System.out.println("baseFun:"+t+" w:"+w);
      }
      if((nv[i+k-1]-nv[i]) !=0 ){
        w2=((t-nv[i])/(nv[i+k-1]-nv[i])) * baseN(i,k-1,t,nv);
        //System.out.println("baseFun:"+t+" w:"+w);
      }
      //System.out.println("baseFun:"+t+" w:"+(w1+w2));
      return (w1+w2);
    }
  }

  void button1_actionPerformed(ActionEvent e) {
    //n=4　制御点数=5　階数：k=3 2次　t=0..3　　多重度=3
    //int [] nv = {0,0,0,1,2,3,3,3};tmax=3;
    //基底関数表示
    //int [] nv = {0,1,2,3,4,5,6,7}; tmax=7;
    if(checkbox1.getState()){nv=nv1;tmax=7;}
    else {nv=nv2;tmax=3;};

    int i,k=0;
    double t;
    funcview=true;

    for(int j=0;j<=4;j++){
      //for(i=0;i<=30;i++){
      for(i=0;i<=tmax*10;i++){
        t=(double)(i)/10;
        if(i==tmax*10) t=t-0.01;//t>=3.0 では基底関数は0になる
        double r=baseN(j,3,t,nv);
        //if(j==3) System.out.println("baseFun:"+t+" "+r);
        //spx[k]=i*10+50;
        spx[k]=i*300/(tmax*10)+20;
        spy[k++]=200-(int)(r*150);
        //System.out.println("btn1:"+j+" k:"+k);
      }
      //nump=31*5;
      nump=(tmax*10+1)*5;
      profile=false;
      repaint();
    }
  }

  void button2_actionPerformed(ActionEvent e) {
    if(checkbox1.getState()){nv=nv1;tmax=7;}
    else {nv=nv2;tmax=3;};
    //曲線の計算
    BspCalc();
    profile=true;
    funcview=false;
    repaint();
  }

  void BspCalc(){
    //int [] nv = {0,0,0,1,2,3,3,3};tmax=3
    //int [] nv = {0,1,2,3,4,5,6,7}; tmax=7;
    double t,r;
    int j;

    for( j=0;j<=tmax*10;j++){
      t=(double)j/10.0;
      if (j==tmax*10) t -= 0.001;//t>=tmax では基底関数は0になる
      double x=0.0,y=0.0;
      for(int i=0;i<=4;i++){
        r=baseN(i,3,t,nv);
        x += px[i]*r;
        y += py[i]*r;
        //if(j<20)System.out.println("drawFun:"+i+" "+x+" "+y+" r:"+r+" t:"+t);
      }
      spx[j]=(int)x;
      spy[j]=(int)y;
      //System.out.println("drawpos:"+j+" "+spx[j]+" "+spy[j]);
    }
    //nump=(tmax*10+1)*5;
    nump=j--;
  }


  double dist(double p1[], double p2[])
  {
     //2点間の距離を返す
    return Math.sqrt((p1[0]-p2[0])*(p1[0]-p2[0])+(p1[1]-p2[1])*(p1[1]-p2[1]));
  }



public void this_mousePressed(MouseEvent e){
  //マウスのボタンが押された
  match=-1;
  double mpoint[]=new double[2];
  double ppoint[]=new double[2];
  //近い点を探す
  mpoint[0]=e.getX();mpoint[1]=e.getY();
  for(int i=0;i<px.length;i++){
    ppoint[0]=px[i];
    ppoint[1]=py[i];
    if (dist(mpoint,ppoint)<10.0){
      match=i;//見つかった
      System.out.println("match:"+match);
      break;
    }
  }
}


public void this_mouseDragged(MouseEvent e){
  //マウスのドラッグがあった
  if (match >= 0) {
    px[match]=e.getX();
    py[match]=e.getY();
  }
  BspCalc();
  repaint();//再表示
  profile=true;
}


  void this_keyReleased(KeyEvent e) {
  match=-1;
  }



}//class