import java.applet.Applet;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.lang.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

//--------------------------------------------------------------------//
//   惑星までの距離						      //
//--------------------------------------------------------------------//

public class planet1 extends Applet{
  int year,mon,day,hour,min,sec;        // 年・月・日・時・分・秒
  int jyear,jmon,jday,jhour,jmin,jsec;  // 日本時間
  double jd,mjd,jjd;                    // ユリウス日・準ユリウス日・日本時間
  double round_jd,round_au,round_km;    // 数値丸め値
  double pi,rad,aukm,tol;
  int fx,fy;                            // 画面フレームサイズ
  int cx1,cy1,cx2,cy2,plr;              // 画面表示の中心位置・マーク大きさ
  double lcoef1,lcoef2;                 // 画面上での1AUの長さ
  SimpleDateFormat formatter;
  Date currentDate;
  Font font;
  double x[]=new double[9];      // 惑星座標位置（太陽原点）
  double y[]=new double[9];
  double z[]=new double[9];
  int gx[]=new int[9];           // 画面上での惑星位置
  int gy[]=new int[9];
  double lens[]=new double[9];   // 太陽からの距離 (AU)
  double lens2[]=new double[9];  // 太陽からの距離 (km)
  double lene[]=new double[9];   // 地球からの距離 (AU)
  double lene2[]=new double[9];  // 地球からの距離 (km)
  double ox[]=new double[360];   // 軌道上点座標値
  double oy[]=new double[360];
  int gox[]=new int[360];        // 画面上での軌道上点位置
  int goy[]=new int[360];

// 惑星の名前
  String namee[]={"Mercury","Venus","Earth","Mars","Jupiter","Saturn",
      	      	  "Uranus","Neptune","Pluto"};
// 表示色
  Color plcolor[]={Color.pink,Color.green,Color.cyan,Color.red,
      	      	   Color.magenta,Color.orange,Color.green,Color.cyan,
      	      	   Color.lightGray};
// 軌道長半径
  double sma[]={0.38710,0.72333,1,1.52368,5.20260,9.55491,19.21845,
      	      	30.11039,39.54034};
// 離心率
  double eccen[]={0.20563,0.00677,0.01671,0.09340,0.04850,0.05555,
      	      	  0.04638,0.00946,0.24901};
// 近日点黄経
  double lofp[]={77.4561,131.5637,102.9373,336.0602,14.3312,93.0572,
      	      	 173.0054,48.1203,224.1416};
// 昇交点黄経
  double lofan[]={48.3309,76.6799,0,49.5581,100.4644,113.6655,74.0059,
      	      	  131.7840,110.3182};
// 軌道傾斜角
  double inc[]={7.0050,3.3947,0,1.8497,1.3033,2.4889,0.7732,1.7700,
      	      	17.1451};
// 平均黄経
  double meanl[]={250.2047,181.1787,99.9736,355.1710,34.3100,50.0607,
      	      	  314.0491,304.3457,238.4650};
// 角速度 °/日
  double pinv[]={4.092377,1.602169,0.985647,0.524071,0.083129,0.033498,
      	      	 0.011769,0.006020,0.004016};

//--------------------------------------------------------------------//
  public void init(){
    year=2000;mon=1;day=1;hour=1;min=10;sec=0;
    jyear=2000;jmon=1;jday=1;jhour=10;jmin=10;jsec=0;
    jd=2450000;mjd=50000;jjd=2450000;
    round_jd=1.0e-5;round_au=1.0e-4;round_km=1.0;tol=1.0e-8;
    fx=600;fy=550;
    cx1=120;cy1=400;cx2=420;cy2=400;plr=3;
    lcoef1=65.0;lcoef2=2.6;
    pi=4*Math.atan(1.0);rad=pi/180.0;aukm=1.4959787e8;
    degreeToRadian(lofp);
    degreeToRadian(lofan);
    degreeToRadian(inc);
    degreeToRadian(meanl);
    degreeToRadian(pinv);
    currentDate = new Date();
    formatter=new SimpleDateFormat("s",Locale.getDefault());
    font=new Font("Monospaced",Font.PLAIN,14);
  }

//--------------------------------------------------------------------//
  public void paint(Graphics g){
    int scale1,scale2,scx1,scy1,scx2,scy2;
    double dth;

    g.setFont(font);
    g.setColor(Color.black);
    g.fillRect(0,0,fx,fy);
    g.setColor(Color.white);

// 現在時刻・ユリウス日
    getCurrentDate();
    jjd=dateToJulianDay(jyear,jmon,jday,jhour,jmin,jsec);
    jd=jjd-0.375;
    mjd=jd-2400000.5;
    julianDayToDate(jd);

// 現在時刻・ユリウス日表示
    g.drawString("JST",5,20);
    writeDate(g,jyear,jmon,jday,jhour,jmin,jsec,50,20);
    g.drawString("GMT",305,20);
    writeDate(g,year,mon,day,hour,min,sec,350,20);
    g.drawString("JD",5,40);
    writeJD(g,jd,50,40);
    g.drawString("MJD",305,40);
    writeJD(g,mjd,350,40);

// 惑星との距離
    e_distance(jd);
    g.drawString("form Earth",5,70);
    for(int i=0;i<namee.length;i++){
      if(i!=2)
      	writeDistance(g,namee[i],lene[i],lene2[i],15,90+20*i);
    }
    g.drawString("form Sun",305,70);
    for(int i=0;i<namee.length;i++){
      writeDistance(g,namee[i],lens[i],lens2[i],315,90+20*i);
    }

// 平面上表示
    dth=2*pi/ox.length;
// 太陽
    g.setColor(Color.yellow);
    g.fillOval(cx1-plr,cy1-plr,2*plr,2*plr);
    g.drawString("Sun",cx1+5,cy1+5);
    g.fillOval(cx2-plr,cy2-plr,2*plr,2*plr);
    g.drawString("Sun",cx2+5,cy2+5);
// 水星−火星
    coordG(x,y,z,gx,gy,cx1,cy1,lcoef1);
    for(int i=0;i<4;i++){
      orbit(dth,sma[i],eccen[i],lofp[i]);
      coordG(ox,oy,gox,goy,cx1,cy1,lcoef1);
      g.setColor(Color.white);
      g.drawPolygon(gox,goy,gox.length);
      g.setColor(plcolor[i]);
      g.fillOval(gx[i]-plr,gy[i]-plr,2*plr,2*plr);
      g.drawString(namee[i],gx[i]+5,gy[i]+5);
    }
// 木星−冥王星
    coordG(x,y,z,gx,gy,cx2,cy2,lcoef2);
    for(int i=4;i<gx.length;i++){
      orbit(dth,sma[i],eccen[i],lofp[i]);
      coordG(ox,oy,gox,goy,cx2,cy2,lcoef2);
      g.setColor(Color.white);
      g.drawPolygon(gox,goy,gox.length);
      g.setColor(plcolor[i]);
      g.fillOval(gx[i]-plr,gy[i]-plr,2*plr,2*plr);
      g.drawString(namee[i],gx[i]+5,gy[i]+5);
    }

// 目盛
    scale1=(int)(lcoef1); scale2=(int)(lcoef2*10);
    scx1=cx1-scale1/2; scy1=cy1+110;
    scx2=cx2-scale2/2; scy2=cy2+110;
    g.setColor(Color.white);
    g.drawLine(scx1,scy1,scx1+scale1,scy1);
    g.drawLine(scx1,scy1-3,scx1,scy1+3);
    g.drawLine(scx1+scale1,scy1-3,scx1+scale1,scy1+3);
    g.drawString("1AU=149597870km",cx1-50,scy1+16);
    g.drawLine(scx2,scy2,scx2+scale2,scy2);
    g.drawLine(scx2,scy2-3,scx2,scy2+3);
    g.drawLine(scx2+scale2,scy2-3,scx2+scale2,scy2+3);
    g.drawString("10AU",cx2-15,scy2+16);

// 春分点
    g.drawLine(cx1+30,cy1,cx1+140,cy1);
    g.drawLine(cx1+140,cy1,cx1+130,cy1-4);
    g.drawLine(cx1+140,cy1,cx1+130,cy1+4);
    g.drawString("distance of",cx1+100,cy1-23);
    g.drawString("vernal equinox",cx1+100,cy1-8);
  }

//--------------------------------------------------------------------//
  void writeDate(Graphics g,int year,int mon,int day,
      	      	 int hour,int min,int sec,int x,int y){
    g.drawString(year+" "+mon+"/"+day+" "+hour+":"+min+":"+sec,x,y);
  }

//--------------------------------------------------------------------//
  void writeJD(Graphics g,double jd,int x,int y){
    jd=(long)(jd/round_jd)*round_jd;
    g.drawString(" "+jd,x,y);
  }

//--------------------------------------------------------------------//
// 惑星までの距離表示
  void writeDistance(Graphics g,String name,double lenau,double lenkm,
      	      	     int x,int y){
    lenau=(long)(lenau/round_au)*round_au;
    lenkm=(long)(lenkm/round_km)*round_km;
    float lenau2=(float)(lenau);
    long lenkm2=(long)(lenkm);
    g.drawString("to "+name+"  "+lenau2+" (AU)"+" = "+lenkm2+" (km)",
      	      	 x,y);
  }

//--------------------------------------------------------------------//
// 現在時刻
  public void getCurrentDate(){
    try{
      jsec=Integer.parseInt(formatter.format(currentDate));
    }
    catch(NumberFormatException ex){
      jsec=0;
    }
    formatter.applyPattern("m");
    try{
      jmin=Integer.parseInt(formatter.format(currentDate));
    }
    catch(NumberFormatException ex){
      jmin=10;
    }    
    formatter.applyPattern("H");
    try{
      jhour=Integer.parseInt(formatter.format(currentDate));
    }
    catch(NumberFormatException ex){
      jhour=10;
    }
    formatter.applyPattern("d");
    try{
      jday=Integer.parseInt(formatter.format(currentDate));
    }
    catch(NumberFormatException ex){
      jday=1;
    }
    formatter.applyPattern("M");
    try{
      jmon=Integer.parseInt(formatter.format(currentDate));
    }
    catch(NumberFormatException ex){
      jmon=1;
    }
    formatter.applyPattern("y");
    try{
      jyear=Integer.parseInt(formatter.format(currentDate));
    }
    catch(NumberFormatException ex){
      jyear=2000;
    }
    if(jyear<100)
      jyear=jyear+2000;
    else if(jyear<200)
      jyear=jyear+1900;
  }

//--------------------------------------------------------------------//
// 角度 °->ラジアン
  void degreeToRadian(double angle[]){
    for(int i=0;i<angle.length;i++){
      angle[i]=Math.toRadians(angle[i]);
    }
  }

//--------------------------------------------------------------------//
// 時刻->ユリウス日
  double dateToJulianDay(int year,int mon,int day,
      	      	      	 int hour,int min,int sec){

    double d2=day+hour/24.0+min/1440.0+sec/86400.0;
    int m2=(mon+9)%12+1;
    int y2=year-(int)(m2/11);
    double jd=(int)(365.25*y2)+(int)(y2/400)-(int)(y2/100)
      	     +(int)(30.59*m2)+d2+1721088.5;
    return jd;
  }

//--------------------------------------------------------------------//
// ユリウス日->時刻
  public void julianDayToDate(double jd){
    int aa=(int)(jd+68569.5);
    int bb=(int)(aa/36524.25);
    int cc=aa-(int)(36524.25*bb+0.75);
    int ee=(int)((cc+1)/365.25025);
    int ff=cc-(int)(365.25*ee)+31;
    int gg=(int)(ff/30.59);
    int hh=(int)(gg/11);
    double ii=jd+0.5-(int)(jd+0.5);
    year=100*(bb-49)+ee+hh;
    mon=gg-12*hh+2;
    day=ff-(int)(30.59*gg);
    hour=(int)(24*ii);
    min=(int)(1440*(ii-hour/24.0));
    sec=(int)(86400*(ii-hour/24.0-min/1440.0));
  }

//--------------------------------------------------------------------//
// ケプラー方程式
  double kepler(double m,double e){
    double ei=m+e*Math.sin(m);
    double mi=ei-e*Math.sin(ei);
    double dm=Math.abs(m-mi);
    while(dm>tol){
      ei=ei+(m-mi)/(1-e*Math.cos(ei));
      mi=ei-e*Math.sin(ei);
      dm=Math.abs(m-mi);
    }
    return ei;
  }

//--------------------------------------------------------------------//
// ３次元２点間距離
  double distance3D(double x1,double y1,double z1,
      	      	    double x2,double y2,double z2){
    double dx=x2-x1;
    double dy=y2-y1;
    double dz=z2-z1;
    return Math.sqrt(dx*dx+dy*dy+dz*dz);
  }

//--------------------------------------------------------------------//
// 画面上座標
  void coordG(double x[],double y[],int gx[],int gy[],
      	      int cx,int cy,double coef){
    for(int i=0;i<x.length;i++){
      gx[i]=cx+(int)(coef*x[i]);
      gy[i]=cy-(int)(coef*y[i]);
    }
  }

//--------------------------------------------------------------------//
// 画面上座標（３次元座標からの変換）
  void coordG(double x[],double y[],double z[],int gx[],int gy[],
      	      int cx,int cy,double coef){
    for(int i=0;i<x.length;i++){
      double lcf=coef*Math.sqrt(1.0+z[i]*z[i]/(x[i]*x[i]+y[i]*y[i]));
      gx[i]=cx+(int)(lcf*x[i]);
      gy[i]=cy-(int)(lcf*y[i]);
    }
  }

//--------------------------------------------------------------------//
// 軌道上点座標
  void orbit(double dth,double sma,double eccen,double lofp){
    for(int i=0;i<ox.length;i++){
      double theta=dth*i;
      double xb=sma*(Math.cos(theta)-eccen);
      double yb=sma*Math.sqrt(1.0-eccen*eccen)*Math.sin(theta);
      ox[i]=xb*Math.cos(lofp)-yb*Math.sin(lofp);
      oy[i]=xb*Math.sin(lofp)+yb*Math.cos(lofp);
    }
  }

//--------------------------------------------------------------------//
// 太陽・地球−惑星間距離
  void e_distance(double jd){
    double jday2=jd-2451545;
    for(int i=0;i<lens.length;i++){
      double m=meanl[i]-lofp[i]+pinv[i]*jday2;
      double eeh=0.5*kepler(m,eccen[i]);
      double v=pi;
      if(Math.cos(eeh)!=0){
      	double tanv=Math.sqrt((1.0+eccen[i])/(1.0-eccen[i]))
      	      	   *Math.sin(eeh)/Math.cos(eeh);
      	v=2*Math.atan(tanv);
      }
      lens[i]=sma[i]*(1.0-eccen[i]*Math.cos(2*eeh));
      double x1=lens[i]*Math.cos(v+lofp[i]);
      double y1=lens[i]*Math.sin(v+lofp[i]);
      double ss=Math.sin(lofan[i]);
      double cc=Math.cos(lofan[i]);
      double x2=x1*cc+y1*ss;
      double y2=-x1*ss+y1*cc;
      double y3=y2*Math.cos(inc[i]);
      z[i]=y2*Math.sin(inc[i]);
      x[i]=x2*cc-y3*ss;
      y[i]=x2*ss+y3*cc;
      lens2[i]=aukm*lens[i];
    }

    for(int i=0;i<lene.length;i++){
      lene[i]=distance3D(x[i],y[i],z[i],x[2],y[2],z[2]);
      lene2[i]=aukm*lene[i];
    }
  }
}