[c++] Problem med new och delete

#ifndef INCLUDED_ENTITY
#define INCLUDED_ENTITY

#include "VGCVirtualGameConsole.h"
#include <vector>
#include <string>
#include <sstream>

class Entity{
public:
	typedef std::vector<Entity*> EntityVector;

	Entity();
	~Entity();
	virtual void move() = 0;
	virtual void render() = 0;
	virtual void tabort();
	double xPosition;
	double yPosition;
	double xVelocity;
	double yVelocity;
	
private:


};
#endif

#include "Entity.h"

using namespace std;

Entity::Entity()
{
	xPosition=0;
	yPosition=0;
	xVelocity=0;
	yVelocity=0;
}

Entity::~Entity(){}

void Entity::tabort(){}

#ifndef INCLUDED_INVADER
#define INCLUDED_INVADER

#include "Entity.h"


class Invader : public Entity{
public:
	Invader();
	~Invader();
	virtual void move();
	virtual void render();
	virtual void tabort(Invader *newinvader);                                   <-- Här är jag osäker om det ska vara som jag har skrivit.
	double xPosition;
	double yPosition;
	double xVelocity;
	double yVelocity;
	static VGCImage invaderimage;

	static void initialize();
	static void finalize();

private:

};

#endif

#include "Invader.h"
#include "Globalconstants.h"
#include "Entity.h"
using namespace std;

VGCImage Invader::invaderimage;

Invader::Invader() : Entity()
{
	xPosition = VGCRandomizer::getDouble(0.0, Globals::DISPLAY_WIDTH - VGCDisplay::getWidth(invaderimage));
	yPosition = -50;
	xVelocity = VGCRandomizer::getDouble(-Globals::MAX_INVADER_SPEED, Globals::MAX_INVADER_SPEED);
	yVelocity = Globals::MAX_INVADER_SPEED;
}
Invader::~Invader(){
	
}

void Invader::move(){	
	xPosition += xVelocity;
	yPosition += yVelocity;
	if((xPosition < 0.0) || (Globals::DISPLAY_WIDTH - VGCDisplay::getWidth(invaderimage) <= xPosition)){
		xVelocity = -xVelocity;
	}

	//if((yPosition >= (Globals::DISPLAY_HEIGHT - VGCDisplay::getWidth(invaderimage))) ){
		//xVelocity = 0;
		//yVelocity = 0;
		
	//}
}

void Invader::tabort(Invader *newinvader)
{
if((yPosition >= (Globals::DISPLAY_HEIGHT - 100)) ){                                    <---  Här har jag tänkt mig att man ska göra en delete då en invader
                                                                                                                      hamnar under ett visst y värde. 
	xVelocity = 0;
		yVelocity = 0;
		
		delete newinvader;	
	}
}
void Invader::render(){
	const VGCVector     position   = VGCVector(int(xPosition), int(yPosition));
	const VGCVector     frameIndex = VGCVector(0,0);
	const VGCAdjustment adjustment = VGCAdjustment(0.0, 0.0);
	VGCDisplay::renderImage(invaderimage, frameIndex, position, adjustment);
}
 
void Invader::initialize(){
	const string invadersFilename        = "Invader.png";
	const int    INVADERS_X_FRAME_COUNT  = 1;
	const int    INVADERS_Y_FRAME_COUNT  = 1;
	Invader::invaderimage                = VGCDisplay::openImage(
		invadersFilename, 
		INVADERS_X_FRAME_COUNT, 
		INVADERS_Y_FRAME_COUNT
	);
}

void Invader::finalize(){
	VGCDisplay::closeImage(invaderimage);
}

#include "Entity.h"
#include "Invader.h"
#include "Ship.h"
//#include "Bullet.h"
using namespace std;

int VGCMain(const VGCStringVector &arguments){

	const string applicationName = "Invader";
	const int    DISPLAY_WIDTH   = 512;
	const int    DISPLAY_HEIGHT  = 512;
	VGCVirtualGameConsole::initialize(applicationName, DISPLAY_WIDTH, DISPLAY_HEIGHT);
	
	Invader::initialize();
	Ship::initialize();

	//skappar ett skepp
	Entity::EntityVector entityVector;
	Ship *newship=new Ship();
	entityVector.push_back(newship);
	
	VGCClock::initializeClock();
	static const double SPAWN_TIME = 1;
	VGCTimer timer = VGCClock::openTimer(SPAWN_TIME);

	while(VGCVirtualGameConsole::beginLoop()){

		if(VGCClock::isExpired(timer)){

			//skappar flera invaders

			Invader *newinvader=new Invader();
			
			entityVector.push_back(newinvader);

			VGCClock::reset(timer);
		}
			
		//flyttar skepp och invader
		for(size_t i = 0; i < entityVector.size(); ++i) {
			entityVector[i]->move();                                                             <---- går igenom vectorn för att se vilka invaders som är under y
                                                                                                                               värdet.    
			entityVector[i]->tabort();

		}
		
		if(VGCDisplay::beginFrame()){

			const VGCColor backgroundColor = VGCColor(255, 0, 0, 0);
			VGCDisplay::clear(backgroundColor);

			for(size_t j = 0; j < entityVector.size(); ++j){
				entityVector[j]->render();

			}
				
			VGCDisplay::endFrame();

		}
	
		VGCVirtualGameConsole::endLoop();

	}
	delete newship;
	
	Invader::finalize();
	Ship::finalize();
	VGCClock::closeTimer(timer);
	VGCClock::finalizeClock();
	VGCVirtualGameConsole::finalize();

	return 0;
}