Messages

1

Graphics / Fixed

« on: February 13, 2012, 07:31:14 am »

Making the engine not a pointer solved the problem.  The reason I made it a pointer was because a book I am reading told me to.  I probably did not allocate memory correctly for it which gave me the error.  Anyway thanks for the help.

2

Graphics / References

« on: February 12, 2012, 09:47:53 pm »

I retried references and it still gave me the same error.  Also, when you pass the sprite into the list dont you get rid of the ampersand?  

Anyway, I thought that if you have to pass objects between classes, especially into a data structure, that you have to use pointers since references are not assignable.  I have also been told by a lot of resources online and in a few books that a list of pointers to sprites on the heap is good way of making a sprite handler as long as you delete them from memory properly.

Any other advice would be appreciated.

3

Graphics / Handler

« on: February 12, 2012, 11:41:27 am »

I forgot to paste that line for the sprite initialization.

sprite = new Sprite();

The main problem now is that I get a bad access error in the sprite handler list in the engine class.  I know that std::list<sf::Sprite> is safer, but as I said before I use my own sprite class in the list and it would also make sense to pass in pointers to sprites rather than the sprites themselves.

So here's what i've got,  I don't really know why this code is a problem as I copied it straight out of a book and don't see any problems with it unless it.  The bad access error occurs when i push_back the list and pass in the sprite.

sprite.h

class Sprite
    {
    protected:
        sf::Image image;
        sf::Sprite sprite;
 
    public:
        Sprite();
        ~Sprite();
       
        bool Load(std::string filename);
    };


main.cpp

    Sprite *sprite;
    sprite = new Sprite();
    sprite->Load("plane.png");
    sprite->Set(100,100);
    g_engine->AddSprite(sprite);

engine.h

std::list<Sprite*> sprites;

engine.cpp

void Engine::AddSprite(Sprite *sprite)
    {
        sprites.push_back(sprite); <- EXC_BAD_ACCESS
    }

4

Graphics / Sprite List Problem

« on: February 11, 2012, 10:49:28 am »

I'm having a problem implementing a sprite list for a game engine that I am making.  I have an abstract sprite class that holds a sf::Image and sf::Sprite object.  In my main file I initialize sprite objects as pointers to pass into the list in the engine class.  However, I get an access error when I try to load the  SFML image.  I know that the error comes from the sf::image going out of scope, but I was wondering how I could alter my code without sacrificing the use of the sprite handler using abstract Sprite objects.

Here is some code:

main.cpp

Sprite *sprite;
sprite->Load("plane.png");
sprite->Set(100,100);
g_engine->AddSprite(sprite);

sprite.h

class Sprite
    {
    protected:
sf::Image image;
sf::Sprite sprite;

public:
        Sprite();
        ~Sprite();
       
        bool Load(std::string filename);

        ...
}

sprite.cpp

bool Sprite::Load(std::string filename)
    {
        if(image.LoadFromFile(filename)) <- EXC_BAD_ACCESS
        {
            sprite.SetImage(image);
            SetWidth(image.GetWidth());
            SetHeight(image.GetHeight());
            return true;
        } else {
            return false;
        }
   }

engine.h

std::list<Sprite*> sprites;