Color Wheel

// Color Wheel - Hue from 0-1 and Saturation from 0-1.
// The example below draws a color wheel that disappears with
// a window event. The applet compares the action of this one
// with another version that draws to an offscreen image buffer.
import java.awt.*;
import java.applet.*;

public class RB1 extends Applet {
   Color color;
   TextField sat, bright;
   Button button;
   
   public void init() {
      repaint();
   }
   
   public void paint (Graphics g) {
      double r1 = 200;
      double pi = 355.0/113.0;
      double c = 0, d = 0;
      int x,y;
      int n=1440;

      for (int j=0 ; j <= 50 ; j++) {
         c=0; d=0;
         for (int i=0 ; i < n ; i++, c+=2*pi/n, d+=1/(double)n ) {
            color = Color.getHSBColor((float)d, (float)((50.0-j)/50.0), (float)1.0);
            g.setColor(color);
            x = (int)(r1*Math.sin(c)+250);
            y = (int)(r1*Math.cos(c)+250);
            g.fillRect(x,y,3,3);
         }
         r1 -= 3;
      }
   }
}