import lejos.nxt.*;
/**
 * A sensor that is able to distinguish a black/dark surface
 * from a white/bright surface.
 * 
 * Light percent values from an active light sensor and a
 * threshold value calculated based on a reading over a 
 * black/dark surface and a reading over a light/bright 
 * surface is used to make the distinction between the two 
 * types of surfaces.
 *  
 * @author  Ole Caprani
 * @version 23.08.07
 */
public class ColorSensor {

   private RCXLightSensor ls; 
   //private LightSensor ls; 
   private int blackLightValue;
   private int whiteLightValue;
   private int blueLightValue;
   private int blackWhiteThreshold;

   public final int Black = 0;
   public final int White = 1;
   public final int Blue = 2;
      
   public ColorSensor(SensorPort p)
   {
	   ls = new RCXLightSensor(p); 
	   // Use the light sensor as a reflection sensor
	   //ls.setFloodlight(true);
	   ls.activate();
   }
    
   public ColorSensor(SensorPort p,int black, int white)
   {
	   ls = new RCXLightSensor(p); 
	   // Use the light sensor as a reflection sensor
	   //ls.setFloodlight(true);
	   ls.activate();
	   
	   blackLightValue = black;
	   whiteLightValue = white;
	   
	   blackWhiteThreshold = (blackLightValue+whiteLightValue)/2;
   }	
   
   public ColorSensor(SensorPort p,int black, int white, int blue)
   {
	   ls = new RCXLightSensor(p); 
	   // Use the light sensor as a reflection sensor
	   //ls.setFloodlight(true);
	   ls.activate();
	   
	   blackLightValue = black;
	   whiteLightValue = white;
	   blueLightValue = blue;
	   
	   blackWhiteThreshold = (blackLightValue+whiteLightValue)/2;
   }
     
   public void setColor(String color, int value)
   {
		
		if(color.equals("Black"))
			blackLightValue = value;
		else if(color.equals("White"))
			whiteLightValue = value;
		else if(color.equals("Blue"))
			blueLightValue = value;
			
		blackWhiteThreshold = (blackLightValue+whiteLightValue)/2;
   }
   
   public boolean black() {
        return (ls.readValue()< blackWhiteThreshold);
   }
   
   public boolean white() {
	   return (ls.readValue()> blackWhiteThreshold);
   }
   
   public boolean blue() {
		int val = ls.readValue();
		
	   //return ( ((blueLightValue + 2) > val) && (val > (blueLightValue - 2)) );
	   return (  (val >= blueLightValue - 1) && (val <= blueLightValue + 1) );
   }
   
   public int light() {
 	   return ls.readValue();
   }
   
}