/****************************************************
 * Joseph Snow, Wayne Witzel and Wes Wariner
 * ASPIRE, University of Utah
 * March 2001
 *
 * NSkySunEarthView class
 */

import java.awt.*;
import java.awt.image.*;
//import com.sun.java.swing.*;
import javax.swing.*;

public class NSkySunEarthView extends JComponent
{
  private Image earthImage;  
  private NSkySunEarthSystem sunEarthSystem;
  private Rectangle sunbounds;
  private Rectangle earthbounds;
  double xdistance;
  double ydistance;
  int xorigin;
  int yorigin;

  double alpha  = Math.PI / 180.0;  /* (2/360) */
  int mar21 = 366-80;
  /* 0=>360, March 21->March 20*, with 0 degrees => East 
        the 80 is the approximate number of days from Jan 1-> Mar 21  */


  public NSkySunEarthView(NSkySunEarthSystem sunEarthSystem, Image earthGlobeImage)
  {
    int sunRadius = 15;
    earthbounds = new Rectangle();
    sunbounds = new Rectangle(getBounds().width/2 - sunRadius, getBounds().height/2 - sunRadius, 
                                sunRadius*2, sunRadius*2);  
    this.sunEarthSystem = sunEarthSystem;
    this.earthImage = earthGlobeImage;
    xdistance = getBounds().width  * 0.325;
    ydistance = getBounds().height * 0.325;
    xorigin = (int)(getBounds().width/2); 
    yorigin = (int)(getBounds().height/2);
  }

  public void setBounds(int x, int y, int width, int height)
  {
    super.setBounds(x, y, width, height);

    // set the sun and earth bounds as well
    sunbounds = new Rectangle(width/2 - sunbounds.width/2, height/2 - sunbounds.height/2, 
                            sunbounds.width, sunbounds.height);
    
    xdistance = getBounds().width  * 0.325;
    ydistance = getBounds().height * 0.325;
    xorigin = (int)(getBounds().width/2); 
    yorigin = (int)(getBounds().height/2);
  }

  public void refresh()
  {
    // This is done here instead of within paintComponent directly
    // for a good reason.  If it is done in paintComponent and then
    // drawn, it tends to cause it to repaint over and over again
    // and slow everything down.
    /* nothing to do */
  }

  public void paintComponent(Graphics g)
  {
    if (earthImage == null) {
        return;
    }

    g.setColor(Color.black);
    g.fillRect(0, 0, this.getWidth(), this.getHeight());

    try {
      /* draw the sun oval */
      g.setColor(Color.white);
      g.fillOval(sunbounds.x, sunbounds.y, sunbounds.width, sunbounds.height);
      //g.setColor(Color.blue);
      //g.drawString("SUN", sunbounds.x, sunbounds.y+ (int)(sunbounds.height*.75));
      
      /* draw the earthglobe */
      int earth_angle = (int)((sunEarthSystem.getCalendar().get(java.util.Calendar.DAY_OF_YEAR) + mar21) * 360.0 / 365.0)%360;
      earthbounds.x =  (int)(Math.cos(alpha*earth_angle)*xdistance + xorigin - earthImage.getWidth(this)/2.0); 
      earthbounds.y = -(int)(Math.sin(alpha*earth_angle)*ydistance - yorigin + earthImage.getHeight(this)/2.0);
      g.drawImage(earthImage, earthbounds.x, earthbounds.y, this);
    }
    catch (Exception e) { }
  }
};