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Help => Graphics => Topic started by: bucknasty189 on April 07, 2011, 06:06:18 pm

Title: Runtime failure at Draw()
Post by: bucknasty189 on April 07, 2011, 06:06:18 pm

I keep getting runtime errors around the line,
m_Game->m_Window.Draw(*m_BackGround);
Please help, I'm utterly confused.
m_BackGround is a Sprite*

Code: [Select]


namespace DE
{
SplashState::SplashState() :
cGameState()
{
}

SplashState::~SplashState()
{
Cleanup();
}

void SplashState::Init(cGameEngine* game)
{
m_Game = game;

sf::Sprite bg;

sf::Image* image = gImageManager.getResource("../data/images/background.jpg");

//sf::Sprite bg(image);
if( image != NULL)
{
bg.SetImage( *image );
}

m_BackGround = &bg;


m_BackGround->SetPosition(m_Game->m_Window.GetWidth()/2,m_Game->m_Window.GetHeight()/2);

m_StartButton = new cp::cpButton(&m_Game->m_Window, &m_Game->m_GUIContainer, "Start", 100, 100, 60, 30);
}

void SplashState::Cleanup()
{
delete m_StartButton;
delete m_Game;
m_StartButton = NULL;
m_Game = NULL;
}

void SplashState::Pause()
{
}

void SplashState::Resume()
{
}

void SplashState::HandleEvents()
{
}

void SplashState::Update()
{
}

void SplashState::Draw()
{
m_Game->m_Window.Draw(*m_BackGround);
m_StartButton->Draw();
}
} //namespace DE


I have my states in an array of cGameState pointers after being told the vector moves around in memory and may screw the address of my image up.
This is how I call the state in my main loop
m_sStack[CURRENT_STATE]->Draw();

Title: Runtime failure at Draw()
Post by: Fred_FS on April 07, 2011, 06:52:29 pm

Hello,
make sure, that you're calling SplashState::Init() before drawing the scene for the first time(The ctor doesn't).
But I wonder, why you create your sprite in such a weird way.
I would prefer:

Code: [Select]


m_Background = new sf::Sprite( *image );


Make also sure that the image exists all the time. SetImage expects a reference to an sf::Image. So if getResource is only loading the image and don't save a copy of it, your application will crash probably ;).

Title: Runtime failure at Draw()
Post by: bucknasty189 on April 07, 2011, 07:09:35 pm

Yeah, I guess that was pointless. Thanks for the help. I guess I'll have to find a way to save that image. My first thought is to use the Asset Manager from the example game engine in  the community wiki.
Any other suggestions?

Title: Runtime failure at Draw()
Post by: Gibgezr on April 07, 2011, 07:14:47 pm

Yeah, do what Fred is suggesting, currently you create a sf::Sprite in the Init() and then it goes out of scope at the end of Init() and the memory is freed, and your m_Background pointer now points to freed memory.

Title: Runtime failure at Draw()
Post by: Nexus on April 07, 2011, 09:06:49 pm

Why do you use Init() and Cleanup()? Aren't the constructor and destructor the better choice, as they ensure proper initialization and destruction?

By the way, not everything needs to be a pointer. Is there a reason why m_BackGround is a sf::Sprite* and not a sf::Sprite? The same applies to other variables...

Title: Runtime failure at Draw()
Post by: bucknasty189 on April 07, 2011, 10:43:45 pm

Thanks for the suggestions. I will get rid of those init and cleanup funcs. And change my members from pointers.