//: color.h : Grafik-Bibliothek ohne Grafiktreiber - R.Richter 2011-01-15
/////////////////////////////////////////////////////////////////////////

#ifndef COLOR_H
#define COLOR_H

// Farben, 24 bit Farbtiefe mit Transparenz (Alpha-Kanal)

class Color
{
public:
  typedef unsigned char Channel;
  typedef unsigned long RGBAlpha;

  enum 
  {
    NONE   = 0xFF000000,
    BLACK  = 0x00000000,
    WHITE  = 0x00FFFFFF,
    RED    = 0x00FF0000,
    GREEN  = 0x0000FF00,
    BLUE   = 0x000000FF,
    YELLOW = 0x00FFFF00
  };

  Color(Channel red, Channel green, Channel blue, Channel alpha = 0)
  : value( rgba(red, green, blue, alpha ) )
  {
  }

  Color(RGBAlpha color = 0xff000000) // default: transparent
  : value(color)
  {
  }

  Channel alpha() const { return Channel(value>>24); }
  Channel red()   const { return Channel(value>>16); }
  Channel green() const { return Channel(value>>8);  }
  Channel blue()  const { return Channel(value);     }

  operator unsigned long() const { return value; }
private:
  RGBAlpha value;

  static RGBAlpha rgba(Channel red, Channel green, Channel blue, Channel alpha)
  {
    return   RGBAlpha(alpha)<<24 | RGBAlpha(red)<<16
	   | RGBAlpha(green)<<8  | RGBAlpha(blue);
  }
};

#endif // COLOR_H
//~