Big class and pointer to that.

[Unregistered]

As my program is getting larger, my class is getting larger too, this is what i now have:

class GlobalDef
{
public:
	//global variables:
	///////////////////
	//General DirectX8 variables
	struct GeneralDX
	{
		IDirect3D8				*d3d8;
		IDirect3DDevice8		*device8;
		D3DDISPLAYMODE			dmode;
		D3DPRESENT_PARAMETERS	e_present;
		D3DCAPS8				Caps;
		//-----------------------------
		D3DDEVTYPE				rastermode;
		DWORD					vertexmode;
		D3DVIEWPORT8			viewport;
		float					aspect;
		//tris/sec specific.
		
	
	}GeneralDX;
	//Time and FPS
	struct TimeAndFPS
	{
		INT64 nFreq;
		INT64 lTickCount;
		INT64 cTickCount;
		int mFrameRate;
		int mFrameCount;
		bool mInited;
		
		//timeelapsed related
		float timeStart;
		float lastTime;
		UINT64 tickspsec;
		
		
	}TimeAndFPS;
	//Matrices
	struct Matrices	
	{
		D3DXMATRIX				matWorld;
		D3DXMATRIX				matView;
		D3DXMATRIX				matProj;
	}Matrices;
	//Misc
	struct Misc
	{
		//application
		RenderTechApplication	EnApp;
		//capabilities
		HWCaps					dcaps;
		//zbuffer struct
		ZModes					zd;
		DWORD					ClearColor;
		RECT					winRect;
		bool					worldcull;
		bool					ShowErrors;
		char*					errstr;
	}Misc;
	
	struct Objects
	{
		//Text related goes here
		vector<FontMan>		Fonts;
		UINT				fontnum;
		RECT				textRect;
		
	}Objects;
	//window structure
	struct WindowStruct
	{
		HWND			hWnd;
		HINSTANCE		hInst;
		int				iWidth;
		int				iHeight;
		char*			clsName;
	}WindowStruct;
	
	struct Input
	{
		//keyboard
		LPDIRECTINPUT8			input8;
		LPDIRECTINPUTDEVICE8	inpdev8;
		char					KeyBuf[256];

		//mouse
		LPDIRECTINPUTDEVICE8	mousedev8;
		//mouse state
		DIMOUSESTATE2			MState;
		DIDEVICEOBJECTDATA		data;
		//used to check if devices are acquired.
		bool kaq;
		bool maq;
	}Input;
	
};

There is a pointer to that class GlobalDef* g;

My question now is, how much overhead there is? Could it be better to use global variables instead of this huge class, which will grow twice as that in the future?

[Davros]

Dunno what you're worring about? It aint big at all.

Just declare a static instance of your class. In this case, your class acts as nothing more than a namespace for your global variables.

[Unregistered]

I shouldnt declare a pointer of it? What would be the difference between a pointer to class and just an instance to it? This class will not (possibly not..) have any functions, only variables.

[Davros]

> I shouldnt declare a pointer of it?

Let me ask, would you do this:

int* a = new int;

or just:

int a;

I suppose the only thing you need to be careful of is the actual size of your class. I notice that many of the data items in it are pointers to other data (hence there are pointers of just 4 bytes).

Do a sizeof on your class. If we are talking about KB's or more make an instance on the heap (as opposed to the stack) by calling new. Then use a static pointer to point to that instance.

i.e.

static GlobalDef* def = new GlobalDef

Otherwise, just declare a static instance in a header file and stop worrying. Like so:

static GlobalDef def;

[Unregistered]

Ok, thank you very much
I was worrying because the class will get very huge.
Cya