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From: bytor@milton.u.washington.edu (Jill Patterson)
Newsgroups: comp.lang.c++
Subject: Multiple Inheritance
Message-ID: <9528@milton.u.washington.edu>
Date: 18 Oct 90 23:08:16 GMT
Sender: bytor@milton.u.washington.edu
Distribution: na
Organization: University of Washington, Seattle
Lines: 86


   	
	Hi, I'm trying to figure out some base classes for some graphical
objects I'm working on.  This is what I have so far:

class Point
{
	public:
		virtual short x() {return 0;}
		virtual short y() {return 0;}
		virtual double wx() {return 0.0;}
		virtual double wy() {return 0.0;}
		virtual double theta() {return 0.0}
		virtual double radius() {return 0.0;}
};

class PhysicalPoint : Point
{
	private:
		short xCoord;
		short yCoord;
	public:
		PhysicalPoint()
		{
			xCoord = 0;
			yCoord = 0;
		}
		PhysicalPoint(short x, short y)
		{
			xCoord = x;
			yCoord = y;
		}
		virtual short x() {return xCoord;}
		virtual short y() {return yCoord;}
};

class LogicalPoint : Point
{
	private:
		double wxCoord;
		double wyCoord;
	public:
		LogicalPoint()
		{
			wxCoord = 0.0;
			wyCoord = 0.0;
		}
		LogicalPoint(double wx, double wy)
		{
			wxCoord = wx;
			wyCoord = wy;
		}
		virtual double wx() {return wxCoord;}
		virtual double wy() {return wyCoord;}
}

class Rectangle
{
	Point *UpLt;
	Point *DnRt;
	Rectangle(Point *ul, Point *dr)
	{
		UpLt = ul;
		DnRt = dr;
	}
}}


	Now with the above definitions I should be able to do this (in TC++)    
right?
	
	LogicalPoint *lPoint = new LogicalPoint(10.0, 10.0);
	LogicalPoint *lPoint2 = new LogicalPoint(30.0, 30.0);

	PhysicalPoint *pPoint1 = new PhysicalPoint(10, 10);
	PhysicalPoint *pPoint2 = new PhysicalPoint(30, 30);

	Rectangle lRect(lPoint1, lPoint2);
	Rectangle pRect(pPoint1, pPoint2);

	By doing this I should get either a Rectangle with short coordinates or
	a Rectangle with double coordinates correct?
	But I can't seem to get them to work,  HELP!

---------------------
bytor@milton.u.washington.edu