SDL projectiles

[L E G I O N]

hey guys i need to make a game that will spawn a new object every 2 seconds
almost like a bullet being shot every 2 seconds and it will move across the screen from left 2 right but i cant seem to get it working... this is my code

#include "SDL.h"
#include "SDL_image.h"
#include <vector>
#include <ctime>
#include <string>
#include <iostream>

using namespace std;

//The surfaces
SDL_Surface *image = NULL;
SDL_Surface *screen = NULL;
SDL_Surface *menuScreen = NULL;
SDL_Surface *background = NULL;

//Screen attributes
const int SCREEN_WIDTH = 800;
const int SCREEN_HEIGHT = 600;
const int SCREEN_BPP = 32;


//The event structure that will be used
SDL_Event event;
 


enum GameState
{
	Menu,
	Level,
	GameOver
}; 

GameState State; 

class WorldObject
{
public:
	int x;
	int y;
	SDL_Surface* surface;

	void Draw()
	{
		apply_surface( x, y, surface, screen);
	}
	virtual void Update(int time)
	{
	}

};


class WorldObjectManager
{
	vector <WorldObject*> WorldList;
	vector <WorldObject*> AddList;
	vector <WorldObject*> RemoveList;

public:
	void AddWorldObject(WorldObject* object)
	{
		WorldList.push_back( object );
	}

	int GetWorldListSize()
	{
		return WorldList.size();
	}

	void DisplayWorld()
	{
		for(int i=0; i < WorldList.size(); i++)
		{
			WorldList[i]->Draw();
		}
	}

	void UpdateWorld(int time)
	{
		MergeAddList();
		for(int i=0; i < WorldList.size(); i++)
		{
			WorldList[i]->Update(time);
		}
	}

	void QueueToAddWorldObject(WorldObject* object)
	{
		AddList.push_back( object );
	}

	void QueueToRemoveWorldObject(WorldObject* object)
	{
		RemoveList.push_back( object );
	}

	void MergeAddList()
	{
		for(int i=0; i < AddList.size(); i++)
		{
			WorldList.push_back(AddList[i]);
		}
		AddList.clear();
	}

	void MergeRemoveList()
	{
		vector<WorldObject*>::iterator iter = RemoveList.begin();
		while( iter != RemoveList.end() )
		{
			WorldList.erase( iter );
			++iter;
		}
		RemoveList.clear();
	}
};
class LivingObject : public WorldObject
{
	int Age;
	int DeathAge;
	int AmountTimeToSpawn;
	int LastSpawnTime;

public:
	LivingObject()
	{
		Age = 0;
		DeathAge = 10000;
		AmountTimeToSpawn = 1500;
		LastSpawnTime = 0;
		surface = load_image("tree1.bmp");
	}
	void Update(int currentTime)
	{
		if( IsDead() )
		{
			cout << "me is dead" << endl;
			manager->QueueToRemoveWorldObject(this);
		}
		
		if( IsReadyToSpawn(currentTime) )
		{
			cout << "spawning, list size: " << manager->GetWorldListSize() << endl;
			//cout << "last spawn time: " << currentTime << endl;
			Spawn();
			LastSpawnTime = currentTime;
		}
		IncreaseAge();
	}
	bool IsDead()
	{
		return Age>=DeathAge;
	}

	bool IsReadyToSpawn(int currentTime)
	{
		int timeElapsed = currentTime - LastSpawnTime;
		return timeElapsed >= AmountTimeToSpawn;
	}

	void IncreaseAge()
	{
		Age++;
	}
	void Spawn()
	{
		LivingObject* object = new LivingObject();
		manager->QueueToAddWorldObject( object );
	}
};


SDL_Surface *load_image( std::string filename )
{
    //The image that's loaded
    SDL_Surface* loadedImage = NULL;

    //The optimized image that will be used
    SDL_Surface* optimizedImage = NULL;

    //Load the image
    loadedImage = IMG_Load( filename.c_str() );

    //If the image loaded
    if( loadedImage != NULL )
    {
        //Create an optimized image
        optimizedImage = SDL_DisplayFormat( loadedImage );

        //Free the old image
        SDL_FreeSurface( loadedImage );
    }

    //Return the optimized image
    return optimizedImage;
}

void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination )
{
    //Temporary rectangle to hold the offsets
    SDL_Rect offset;

    //Get the offsets
    offset.x = x;
    offset.y = y;

    //Blit the surface
    SDL_BlitSurface( source, NULL, destination, &offset );


}
int main( int argc, char* args[] )
{
    bool quit = false;

    Initalize();

	SetupWorld();

    //While the user hasn't quit
    while( quit == false )
    {
		SDL_Delay(100);
		GameLoop();
		if( SDL_Flip( screen ) == -1 )
		{
			return 1;
		}
        //While there's an event to handle
        while( SDL_PollEvent( &event ) )
        {
			if (event.type == SDL_KEYDOWN)
			{
				if (event.key.keysym.sym == SDLK_RETURN)
					State = Level;
			}
            //If the user has Xed out the window
            if( event.type == SDL_QUIT )
            {
                //Quit the program
                quit = true;
            }
        }
    }

    //Free the surface and quit SDL
    clean_up();

    return 0;


}

void clean_up()
{
    //Free the surface
    SDL_FreeSurface( image );
	SDL_FreeSurface( menuScreen );
    //Quit SDL
    SDL_Quit();
}

please if anybody knows what i'm doing wrong please tell me ... lol

[L E G I O N]

i know its alot to read... but has anyone taken a look or can offer some advice...i might be doing this the hard way...if there's a more efficient route to take i would be more then willing to hear some advice....

[moorecm]

Don't forget to delete any memory allocated with operator new().

[tehpwnererer]

I am also having the same kind of issue.

[y8h7M4Gy]

why don't you just reset the bullet's x axis after it goes off the other side of the screen?
Do you want to make an open source game? I want a partner for a platform game I'm making :P

[y8h7M4Gy]

also, if you want to make something spawn every certain amount of time.. take a look at this tutorial...

http://lazyfoo.net/SDL_tutorials/lesson28/index.php

it isn't directly telling you how to do it, but it should be easy to figure it out from there

Hope this helps