// class Treasure: Models an individual item of treasure: a star

// sbj May 1998; updated to Java 1.1 May 1999

import java.awt.*;

class Treasure {

  // The next four lines define the applet game area.
  // They assume the applet tag says WIDTH=400, HEIGHT=300
  // and allow 20 pixel borders at top and bottom for widgets,
  // and all treasures centred at least 20 pixels from the edge
  
  private final int windowWidth = 400;
  private final int windowHeight = 300;
  
  private final int minX = 20, maxX = windowWidth-20;; 
  private final int minY = 40, maxY = windowHeight-40;
  
  private final int scale = (int)(Math.random()*19+2);
                                 // A random size measure for the treasure icon
                                 // Half the star's height in pixels
   
  private int[] xs, ys;          // To hold the points of the star icon
  private Color color;           // Its colour
  public boolean collected;      // False to start with, then set true when collected
  
  public Treasure() {            // Constructor: Define a star polygon at a random position
    color = new Color((int)(Math.random()*256),   // Pick a random colour usign RGB coding
                      (int)(Math.random()*256),
                      (int)(Math.random()*256));
    collected = false;
    int baseX = (int) (Math.random()*(maxX-minX)+minX);  // Random centre position in window
    int baseY = (int) (Math.random()*(maxY-minY)+minY);
    xs = new int[9];             // Set up the star's points at coordinates
    ys = new int[9];             // (x[0],y[0]), x[1],y[1]), ... etc
    xs[0] = baseX;       xs[1] = baseX+scale/4; xs[2] = baseX+scale; xs[3] = baseX+scale/4;
    ys[0] = baseY-scale; ys[1] = baseY-scale/4; ys[2] = baseY;       ys[3] = baseY+scale/4;
    xs[4] = baseX;       xs[5] = baseX-scale/4; xs[6] = baseX-scale; xs[7] = baseX-scale/4;
    ys[4] = baseY+scale; ys[5] = baseY+scale/4; ys[6] = baseY;       ys[7] = baseY-scale/4;
    xs[8] = baseX;
    ys[8] = baseY-scale;
  }
  
  public boolean within(int x, int y) {         // Is x, y inside the star?
    Polygon p = new Polygon(xs, ys, 9);
    return p.contains(x, y);                    // contains is method in Polygon library class
  }
  
  public void collect() {                       // Record that this treasure has been collected
    collected = true;
  }
  
  public void display(Graphics g) {
    if (collected) return;                      // Don't display if already collected
    g.setColor(color);
    g.fillPolygon(xs, ys, 9);                   // The interior
    g.setColor(Color.black);
    g.drawPolygon(xs, ys, 9);                   // The border
  }

} // End of Treasure