//
//	File:	line.cpp
//	p.169
//
//	Define a line class that illustrate 
//	a line at coordinates
//


#include <iostream>
#include <iomanip>	// for setprecision

using namespace std;

class Point
{	// data
private:
	int x, y;
public:
	// constructors
	Point ()
	{	x = y = 0;	}
	Point (int a, int b)
	{	x = a;
		y = b;
	}
	// p.168
	float Distance (Point p) const
	{	float d;
		int x0, y0;
		x0 = x - p.x;
		y0 = y - p.y;
		d = sqrt(1.0*x0*x0 + y0*y0);
		return d;
	}
};

// define a subclass of Point, named Pixel, p.167

enum StatusType {ON, OFF};

class Pixel : public Point
{	StatusType status;
public:
	Pixel()	// (0, 0) OFF
	{	status = OFF;	}
	Pixel( int a, int b, StatusType s)
	: Point(a, b)
	{	status = s;	}
};

class Line
{	Point startP, endP;
public:
	Line(int sx, int sy, int ex, int ey)
	: startP(sx, sy), endP(ex, ey)
	{	}
	float Length() const
	{
		return startP.Distance(endP);
	}
};
		
		


int main()
{       // p.168 #2
        Pixel onePixel (1, 1, ON);
        Pixel origin;                   // (0, 0) OFF

	cout << fixed << showpoint << setprecision(1);

        // #3
        cout << "The dis from origin to onePixel: "
                << onePixel.Distance(origin);

	// p.169 #b
	Line L1(1,1,0,0);
	cout << "\n\nLine length: " << L1.Length();


	cout << "\n\nDone.\n\n";
	return 0;
}