import java.io.*;
import java.lang.*;

/** 
  * PointLight represents a light sources that illuminates from a
  * fixed origin
  *
  * @author Anthony Steed
  * @version 1.0
  */

public class PointLight extends Light {
  /**
    * Stores the origin of the point light.
    */
  
  public Point Origin;
  
  /**
    * Create a default light.
    */
  public PointLight() {
    Intensity = new Colour(1.0,1.0,1.0);
    Origin = new Point();
  }
  
  /**
    * Create a new point light that at the given point.
    * @param p The position of the light.
    */
  public PointLight(Point p) {
    Intensity = new Colour(1.0,1.0,1.0);
    Origin = p;
  }
  
  /**
    * Read the light from the given source
    * @param is The source to read from
    * @exception java.io.IOException
    * if the light can not be read
    * @exception java.io.NumberFormatException
    * if there a number format error is encountered
    */
  public void read(SceneReader is) 
    throws IOException, NumberFormatException {
      Intensity.read(is);
      Origin.read(is);
  }

  /**
    * Write the light to the given destination
    * @param os  The destination to write to
    * @exception java.io.IOException
    * if the write fails.
    */
  public void write(SceneWriter os) throws IOException {
    Intensity.write(os);
    os.writeChar(' ');
    Origin.write(os);
  }

  /** 
    * Print a human readable version of the light definition to the
    * given destination
    * @param os  The destination to write to
    * @exception java.io.IOException
    * if the write fails.
    */
  public void print(SceneWriter os) throws IOException {
    os.writeString("Point light with colour: ");
    Intensity.print(os);
    os.writeString(" and origin: ");
    Origin.print(os);
    os.writeString("\n");
  }
}