///////////////////////////////////////////////////////////////////////////////
// Pixel.h
// 
//     This data class contains the information required to represent one
// pixel of graphics data.  Several different color models are provided,
// you may access each pixel using whichever model you want.
///////////////////////////////////////////////////////////////////////////////

// The following preprocessor directives makes sure this header
// only gets included once.

#ifndef PIXEL_HSPC
#define PIXEL_HSPC

// Define the Pixel class.

class Pixel
{
  public:
    // Default constructor -- creates a black pixel.
  
    Pixel ();

    // Destructor -- frees up any memory used.
  
    ~Pixel ();

    // These routines are used for getting at the color values of this
    //   pixel.  The range for each value is 0.0 to 1.0 inclusive.

    // The RGB model for the color.
    double getRed ();
    double getGreen ();
    double getBlue ();

    // The HSV model for the color.
    double getHue ();
    double getSaturation ();
    double getIntensity ();

    // The YIQ model for the color.
    double getBrightness ();
    double getChroma ();
    double getPurity ();

    // The CMY model for the color.
    double getCyan ();
    double getMagenta ();
    double getYellow ();
  
    // These routines are used for setting the color of the pixel.

    void setRGBColor (double red, double green, double blue);
    void setHSVColor (double hue, double saturation, double intensity);
    void setYIQColor (double brightness, double chroma, double purity);
    void setCMYColor (double cyan, double magenta, double yellow);
    
  // These routines are used for tweaking the color of a pixel.  Note
  //   that if you change a value in one color model, it will affect
  //   all the other representations of the color.  Use these routines
  //   with great care.  (You don't have to ever use these routines).
  //   The range for each value is 0.0 to 1.0 inclusive.

    // The RGB model for the color.
    void adjustRed   (double newValue);
    void adjustGreen (double newValue);
    void adjustBlue  (double newValue);

    // The HSV model for the color.
    void adjustHue        (double newValue);
    void adjustSaturation (double newValue);
    void adjustIntensity  (double newValue);

    // The YIQ model for the color.
    void adjustBrightness (double newValue);
    void adjustChroma     (double newValue);
    void adjustPurity     (double newValue);

    // The CMY model for the color.
    void adjustCyan    (double newValue);
    void adjustMagenta (double newValue);
    void adjustYellow  (double newValue);
    
  private:

    // Color model information.

    typedef enum {RGB, HSV, YIQ, CMY} ColorModel;
  
    // The color information is stored here.

    ColorModel model;  // 0=RGB, 1=HSV, 2=YIQ, 3=CMY
  
    union
    {
      double red;
      double hue;
      double brightness;
      double cyan;
      double value1;
    };

    union
    {
      double green;
      double saturation;
      double chroma;
      double magenta;
      double value2;
    };

    union
    {
      double blue;
      double intensity;
      double purity;
      double yellow;
      double value3;
    };
  
    // This function makes sure all the values are in the range [0.0 ... 1.0].
  
    void clipValues ();

  // A color conversion helper function.
  
    void convertTo (ColorModel newModel);

};

#endif // IMAGE_HSPC