Hi, I have written a method in my sprite class which returns me the value for the sprite interface. CSprite.h: LPD3DXSPRITE m_pD3DSprite; CSprite.cpp CSprite::CSprite() { m_pD3DSprite = NULL; } LPD3DXSPRITE CSprite::GetD3DSprite() { return m_pD3DSprite; } In my main class I initialize the sprite interface and store m_pD3DSprite for rendering sprites in my game loop. CMain.cpp: VOID CMain::Initialize() { m_sprite.Initialize(); m_pD3DSprite = m_sprite.GetD3DSprite(); } VOID CMain::Render() { m_pD3DDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB( 0, 0, 0 ), 1.0f, 0 ); m_pD3DDevice->BeginScene(); m_pD3DSprite->Begin( D3DXSPRITE_ALPHABLEND ); m_menu.Draw(); <-- This causes the error message. Without this line everything works fine. m_pD3DSprite->End(); m_pD3DDevice->EndScene(); m_pD3DDevice->Present( NULL, NULL, NULL, NULL ); } In my menu class I need the sprite interface for making draw calls. CMenu.cpp: CMenu::CMenu() { m_pD3DSprite = NULL; m_pD3DSprite = m_sprite.GetD3DSprite(); } VOID CMenu::DrawMain() { m_pD3DSprite->Draw( ... ); } But everytime I use GetD3DSprite() in my menu class I get an acess violation at position 0x00000000. So why is it that GetD3DSprite() works in my main class but not in my menu class?

Quote:Original post by Moe Szyslack
But everytime I use GetD3DSprite() in my menu class I get an acess violation at position 0x00000000. So why is it that GetD3DSprite() works in my main class but not in my menu class?

Have you actually initialised the sprite pointer in your menu class? It looks to me like you have two ID3DXSprite interfaces, and you only initialise one (And you should really only have one for your entire app btw).

As far as I could tell, m_pD3DSprite initialized in the main is not accessible by your Menu class. You'd have to make m_pD3DSprite static, or pass in the pointer to your menu constructor.

Actually I'm initializing the sprtie interface in my sprite class.

CSprite.h:

class CSprite
{
public:
LPD3DXSPRITE GetD3DSprite();
...

private:
LPD3DXSPRITE m_pD3DSprite;
...
};

CSprite.cpp:

VOID CSprite::Initialize( LPDIRECT3DDEVICE9 pD3DDevice )
{
if( FAILED( D3DXCreateSprite( pD3DDevice, &m_pD3DSprite ) ) )
{
MessageBox( NULL, "CSprite::Initialize: D3DXCreateSprite() fehlgeschlagen.", "Error", NULL );
}

if( m_pD3DSprite == NULL )
{
MessageBox( NULL, "CSprite::Initialize: m_pD3DSprite == NULL.", "Error", NULL );
}
}

In my main class and my menu class I include the sprite class and use GetD3DSprite() to get the sprite interface.

Quote:Original post by Moe Szyslack
Actually I'm initializing the sprtie interface in my sprite class.

[snip]

In my main class and my menu class I include the sprite class and use GetD3DSprite() to get the sprite interface.

I'm confused. Where is m_sprite declared? If you have a separate copy of that in CMenu and CMain, you'll need each versions Initialize() function called. If you break to the debugger when you get the access violation, what is NULL? You could try adding some logging to check where the pointers are initialized.

Quote:Original post by dmatter
As a separate note, shouldn't the menu class be responsible for calling Begin( D3DXSPRITE_ALPHABLEND )?

I thought it wood be faster if I call only one time per frame Begin( D3DXSPRITE_ALPHABLEND ) and not everytime I draw a sprite. But if it makes no remarkable difference in speed I will change that.

Quote:Original post by Evil Steve
I'm confused. Where is m_sprite declared? If you have a separate copy of that in CMenu and CMain, you'll need each versions Initialize() function called. If you break to the debugger when you get the access violation, what is NULL? You could try adding some logging to check where the pointers are initialized.

m_sprite is declared in CMain and CMenu:


CMain.h:

#include "CSprite.h"

class CMain
{
private:
CSprite m_sprite;
...
};


CMenu.h:

#include "CSprite.h"

class CMenu
{
private:
CSprite m_sprite;
...
};

So, if I understand you right I have to call m_sprite.Initialize() in CMain and in CMenu?

Quote:Original post by Moe Szyslack
So, if I understand you right I have to call m_sprite.Initialize() in CMain and in CMenu?

Yes. You have two separate sprites there, so you need to initialize each one.

As I said though; it'd be more performant to have a single sprite instance instead of multiple ones.

Ah ok, that explains that behaviour. But how can I achieve to have just one sprite interface? I thought I'm doing it already with initializing the sprite interface in my sprite class and passing the variable via the GetD3DSprite() method to any other class who needs it.