// Body object
// Needed for Nbody.class
// M.Dubson ENVD 3252 final project

import java.awt.*;

public final class Body
{
  double xPos, yPos, vX, vY, aX, aY;
  double xInit, yInit, vXInit, vYInit;
  double vXInitCM, vYInitCM;  //initial velocity in C.M. frame
  double xLast, yLast;
  double xLastPaint, yLastPaint;
  double aXLast, aYLast, aXBeforeLast, aYBeforeLast;
  double mass;
  static double velFactor = 0.01;
  int radius;
  Color color;
  static Color colorArray[]= {Color.red, Color.orange, Color.green, 
                  Color.blue,Color.yellow, Color.white, Color.pink};
  int w = 400;
  int h = 300;
  double xMovie[] = new double [10000];
  double yMovie[] = new double [10000];
  double vXMovie[] = new double [10000];
  double vYMovie[] = new double [10000];
  
  double pX = mass*vX;
  double pY = mass*vY;
  
  public Body (int i)
  {
      if (i == 0)
      {
        xPos = 0.3*w; yPos = 0.5*h;
        vX = 0.0; vY = 0.0;
        mass = 400;
      }
      if (i == 1)
      {
        xPos = 0.8*w; yPos = 0.5*h;
        vX = 0.0; vY = -0.05;
        mass = 2;
      }  
      if (i == 2)
      {
        xPos = 0.9*w; yPos = 0.3*h;
        vX = 1.0; vY = 0.0;
        mass = 0;
      }     
      //mass = (double) Math.round(Math.random()*100);   //30.0;
      radius = 1 + (int) (1.5*Math.pow(mass, 0.333));
      //xPos = Math.random()*w*0.8; yPos = Math.random()*h*0.6 + h*0.2;
      xLast = xPos; yLast = yPos; 
      xLastPaint = xPos; yLastPaint = yPos;
      //vX = 0.0; vY = 0.0;
      xInit = xPos; yInit = yPos; vXInit = vX; vYInit = vY;
      color = colorArray[i];
      //System.out.println("Red is "+ rV + ". Green is "+gV+". Blue is "+bV+".");
  }
  
  public Body ( double massBody, int r, double x, double y, double velX, double velY)
  {
    mass = massBody;
    radius = r;
    xPos = x; yPos = y; 
    vX = velX; vY = velY;
  }
  
  public final void paint(Graphics g)
  {
      g.setColor(color);
      g.fillOval((int)xPos - radius, (int)yPos - radius, 2*radius, 2*radius);
      g.drawLine((int) xPos, (int) yPos, (int) (xPos + vX/velFactor) , (int) (yPos + vY/velFactor));
      //g.setColor(Color.black);
      //g.drawOval((int)xPos - radius, (int)yPos - radius, 2*radius, 2*radius);     
  }
  public final void paintTrajectory(Graphics g)
  {
      g.setColor(color);
      g.drawLine((int) xLastPaint, (int) yLastPaint, (int)xPos , (int)yPos );   
  }  
  
  public final void posPaintIn(Graphics g, int xNow, int yNow)
  {
    //int vXs = (int) (vX/velFactor); int vYs = (int) (vY/velFactor);
    g.setColor(color);
    g.fillOval(xNow - radius, yNow - radius, 2*radius, 2*radius);
    //g.drawLine(xNow, yNow, xNow + vXs , yNow + vYs); 
    //g.setColor(Color.black);
    //g.drawOval(xNow - radius, yNow - radius, 2*radius, 2*radius);   
  }

  public final void velPaintIn(Graphics g, int xNow, int yNow)
  {
    g.setColor(color);
    g.fillOval((int) xPos - radius, (int) yPos - radius, 2*radius, 2*radius);
    g.drawLine((int)xPos, (int) yPos, xNow , yNow);
    //g.setColor(Color.black);
    //g.drawOval((int)xPos - radius, (int)yPos - radius, 2*radius, 2*radius);   
  }
  
  public final void paintOut(Graphics g)
  {
     int vXs = (int) (vX/velFactor); int vYs = (int) (vY/velFactor);
     g.setColor(Color.black);
     g.fillOval((int) xPos - radius, (int) yPos - radius, 2*radius, 2*radius);
     //g.drawOval((int)xPos - radius, (int)yPos - radius, 2*radius, 2*radius);
     g.drawLine((int)xPos , (int)yPos , (int)xPos + vXs, (int)yPos + vYs);     
  }
  
  public final void setR(int xNow, int yNow)
  { 
    xPos = (double) xNow;
    yPos = (double) yNow;
    xInit =  (double) xNow;
    yInit =  (double) yNow;
    xLastPaint =  (double) xNow;
    yLastPaint =  (double) yNow;
  }
  
  public final void setV(int xNow, int yNow)
  {
    vX = velFactor* ((double) xNow - xPos);
    vY = velFactor* ((double) yNow - yPos);
  }
  
  
  public boolean bodClicked (int x, int y)
  {
    if ( x >= (int) xPos - radius && x <= (int) xPos + radius 
          && y >= (int) yPos - radius && y <= (int) yPos + radius )
    {
        return true;
    }
    else return false;
  }//end of bodClicked method

  public boolean velClicked (int x, int y)
  {
    int vXs = (int) (vX/velFactor); int vYs = (int) (vY/velFactor);
    if ( x >= (int) xPos + vXs - radius && x <= (int) xPos + vXs + radius 
          && y >= (int) yPos + vYs - radius && y <= (int) yPos + vYs + radius )
    {
        return true;
    }
    else return false;
  }//end of velClicked method
  
}//end of class Body