// Pixel.h        Dave Reed
//
// Definitions of classes in the Pixel hierarchy
//   Pixel:      abstract class that specifies operations on all pixel types
//   MonoPixel:  for black and white (PBM) images
//   GrayPixel:  for grayscale (PGM) images
//   ColorPixel: for color (PPM) images
/////////////////////////////////////////////////////////////////////////////

#ifndef _PIXEL_H_
#define _PIXEL_H_

#include <iostream>
#include <fstream>
using namespace std;

class Pixel
{
  public:
    virtual void Invert() = 0;
    virtual void Read(istream & istr) = 0;
    virtual void Write(ostream & ostr) = 0;
};

class MonoPixel : public Pixel
{
  public:
    MonoPixel();
    void Invert();
    void Read(istream & istr);
    void Write(ostream & ostr);
  private:
    short int pixValue;
};

class GrayPixel : public Pixel
{
  public:
    GrayPixel(int max = 1);
    void Invert();
    void Read(istream & istr);
    void Write(ostream & ostr);
  private:
    int pixValue;
    int maxValue;
};

class ColorPixel : public Pixel
{
  public:
    ColorPixel(int max = 1);
    void Invert();
    void Read(istream & istr);
    void Write(ostream & ostr);
  private:
    int redValue, greenValue, blueValue;
    int maxValue;
};

#endif