MAIN.CXX

One of the most powerful tools of Object Oriented Programing is called polymorphism.
Polymorphism allows you to point to any object derived from the type of your pointer.
This means that we can derive another class from ball and handle it similiarly in our vector.

#include <vector.h>
#include <iostream.h>
#include "gravityBall.h"

int main (void)
	{
	sphere mySphere;
	mySphere.setRadius(10.0);
	cout << "mySphere has radius: " << mySphere.getRadius() << endl;
	sphere myOtherSphere;
	myOtherSphere.copy(mySphere);
	myOtherSphere.setPosition(3.0,4.0,10.0);
	cout << "myOtherSphere has radius: " << myOtherSphere.getRadius() << endl;
	cout << "myOtherSphere has X position: " << myOtherSphere.getXPosition() << endl;
	vector<ball*> myBallArray;
	//create a new ball
	myBallArray.push_back(new ball);
	//initialize the ball position
	myBallArray.front()->setPosition(3.0,4.0,10.0);
	myBallArray.front()->setRadius(20.0);
	myBallArray.front()->setVelocity(0.2,0.0,1.0);
	while (1)
		{
		//report the ball position and velocity of the last ball created
		cout << "ballNumber: " << myBallArray.size()-1 << endl;
		cout << "myBall has position X: " << myBallArray.back()->getXPosition();
		cout << " Y: " << myBallArray.back()->getYPosition();
		cout << " Z: " << myBallArray.back()->getZPosition() << endl;
		cout << "myBall has velocity X: " << myBallArray.back()->getXVelocity();
		cout << " Y: " << myBallArray.back()->getYVelocity();
		cout << " Z: " << myBallArray.back()->getZVelocity() << endl;
		vector<ball*>::iterator i;
		for (i=myBallArray.begin(); i!=myBallArray.end(); i++)
			{
			//simulate the ball flight
			(*i)->fall();
			//delete the ball if resting
			if ((*i)->getZPosition() <= 0.0)
				{
				//delete the ball from memory
				delete (*i);
				//delete the ball from the vector
				myBallArray.erase(i);
				}
			}
		//generate a random number between 0 and 100
		int randomNumber = random()%100;
		//create a new ball 25 percent of the time
		if (randomNumber < 25)
			{
			//create a new ball
			myBallArray.push_back(new ball);
			//initialize the ball position
			myBallArray.back()->setPosition(3.0,4.0,10.0);
			myBallArray.back()->setRadius(20.0);
			myBallArray.back()->setVelocity(0.2,0.0,1.0);
			}
		//and, create a new gravity ball 25 percent of the time
		else if (randomNumber < 50)
			{
			//create a new ball
			myBallArray.push_back(new gravityBall);
			//initialize the ball position
			myBallArray.back()->setPosition(3.0,4.0,10.0);
			myBallArray.back()->setRadius(20.0);
			myBallArray.back()->setVelocity(0.2,0.0,1.0);
			}
		}
	};