为什么用VC++6.0编译的OpenGL程序占用内存都至少有20兆？

[seaboy100]

如题。我使用Nehe的OpenGL教程中的源代码作为模版经过修改后编译的，除了十几个全局变量外并没有用大数组等可能占用内存的东西（为了测试只画了一个6个面组成的立方体），可Release在运行时内存占用总是在20兆以上（除此外还占用20多兆虚拟内存）。我的操作系统是windowsXP sp3。
这样正常吗？是不是所有只要用到OpenGL的程序都得至少占用20兆内存？

[zhouzhipen]

不正常,可能你的动太分配了太多的内存

[zhao1zhong6]

我一直用directx,但我能肯定跟(程序本身大小)和(编译器)没有任何关系.

[seaboy100]

我没有动态分配内存，要不然我就不会提这个问题了。
我用的是C语言、纯sdk，没有用MFC等，除了调用windows标准API和gl函数外其余所有代码都是自己实现的。release程序只有30多KB而已。
所以我才奇怪，怎么会占用那么多内存？

[seaboy100]

另，需要的话，我用的模版代码就是这样(这个模版没有渲染任何东西，只是进行了一些初始化工作，显示一个空白窗口，但运行时仍然占用20兆内存）：

/*
 *		This Code Was Created By Jeff Molofee 2000
 *		A HUGE Thanks To Fredric Echols For Cleaning Up
 *		And Optimizing This Code, Making It More Flexible!
 *		If You've Found This Code Useful, Please Let Me Know.
 *		Visit My Site At nehe.gamedev.net
 */

#include <windows.h>		
#include <gl\gl.h>			
#include <gl\glu.h>			
#include <gl\glaux.h>		

HDC			hDC=NULL;		
HGLRC		hRC=NULL;		
HWND		hWnd=NULL;		
HINSTANCE	hInstance;		

bool	keys[256];			
bool	active=TRUE;		
bool	fullscreen=TRUE;	

LRESULT	CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);	

GLvoid ReSizeGLScene(GLsizei width, GLsizei height)		
{
	if (height==0)										
	{
		height=1;										
	}

	glViewport(0,0,width,height);						

	glMatrixMode(GL_PROJECTION);						
	glLoadIdentity();									

	
	gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);

	glMatrixMode(GL_MODELVIEW);							
	glLoadIdentity();									
}

int InitGL(GLvoid)										
{
	glShadeModel(GL_SMOOTH);							
	glClearColor(0.0f, 0.0f, 0.0f, 0.5f);				
	glClearDepth(1.0f);									
	glEnable(GL_DEPTH_TEST);							
	glDepthFunc(GL_LEQUAL);								
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);	
	return TRUE;										
}

int DrawGLScene(GLvoid)									
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	
	glLoadIdentity();									
	return TRUE;										
}

GLvoid KillGLWindow(GLvoid)								
{
	if (fullscreen)										
	{
		ChangeDisplaySettings(NULL,0);					
		ShowCursor(TRUE);								
	}

	if (hRC)											
	{
		if (!wglMakeCurrent(NULL,NULL))					
		{
			MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		}

		if (!wglDeleteContext(hRC))						
		{
			MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		}
		hRC=NULL;										
	}

	if (hDC && !ReleaseDC(hWnd,hDC))					
	{
		MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hDC=NULL;										
	}

	if (hWnd && !DestroyWindow(hWnd))					
	{
		MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hWnd=NULL;										
	}

	if (!UnregisterClass("OpenGL",hInstance))			
	{
		MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hInstance=NULL;									
	}
}

BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag)
{
	GLuint		PixelFormat;			
	WNDCLASS	wc;						
	DWORD		dwExStyle;				
	DWORD		dwStyle;				
	RECT		WindowRect;				
	WindowRect.left=(long)0;			
	WindowRect.right=(long)width;		
	WindowRect.top=(long)0;				
	WindowRect.bottom=(long)height;		

	fullscreen=fullscreenflag;			

	hInstance			= GetModuleHandle(NULL);				
	wc.style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;	
	wc.lpfnWndProc		= (WNDPROC) WndProc;					
	wc.cbClsExtra		= 0;									
	wc.cbWndExtra		= 0;									
	wc.hInstance		= hInstance;							
	wc.hIcon			= LoadIcon(NULL, IDI_WINLOGO);			
	wc.hCursor			= LoadCursor(NULL, IDC_ARROW);			
	wc.hbrBackground	= NULL;									
	wc.lpszMenuName		= NULL;									
	wc.lpszClassName	= "OpenGL";								

	if (!RegisterClass(&wc))									
	{
		MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;											
	}
	
	if (fullscreen)												
	{
		DEVMODE dmScreenSettings;								
		memset(&dmScreenSettings,0,sizeof(dmScreenSettings));	
		dmScreenSettings.dmSize=sizeof(dmScreenSettings);		
		dmScreenSettings.dmPelsWidth	= width;				
		dmScreenSettings.dmPelsHeight	= height;				
		dmScreenSettings.dmBitsPerPel	= bits;					
		dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;

		
		if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL)
		{
			
			if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES)
			{
				fullscreen=FALSE;		
			}
			else
			{
				
				MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP);
				return FALSE;									
			}
		}
	}

	if (fullscreen)												
	{
		dwExStyle=WS_EX_APPWINDOW;								
		dwStyle=WS_POPUP;										
		ShowCursor(FALSE);										
	}
	else
	{
		dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;			
		dwStyle=WS_OVERLAPPEDWINDOW;							
	}

	AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);		

	
	if (!(hWnd=CreateWindowEx(	dwExStyle,							
								"OpenGL",							
								title,								
								dwStyle |							
								WS_CLIPSIBLINGS |					
								WS_CLIPCHILDREN,					
								0, 0,								
								WindowRect.right-WindowRect.left,	
								WindowRect.bottom-WindowRect.top,	
								NULL,								
								NULL,								
								hInstance,							
								NULL)))								
	{
		KillGLWindow();								
		MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								
	}

	static	PIXELFORMATDESCRIPTOR pfd=				
	{
		sizeof(PIXELFORMATDESCRIPTOR),				
		1,											
		PFD_DRAW_TO_WINDOW |						
		PFD_SUPPORT_OPENGL |						
		PFD_DOUBLEBUFFER,							
		PFD_TYPE_RGBA,								
		bits,										
		0, 0, 0, 0, 0, 0,							
		0,											
		0,											
		0,											
		0, 0, 0, 0,									
		16,											
		0,											
		0,											
		PFD_MAIN_PLANE,								
		0,											
		0, 0, 0										
	};
	
	if (!(hDC=GetDC(hWnd)))							
	{
		KillGLWindow();								
		MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								
	}

	if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd)))	
	{
		KillGLWindow();								
		MessageBox(NULL,"Can't Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								
	}

	if(!SetPixelFormat(hDC,PixelFormat,&pfd))		
	{
		KillGLWindow();								
		MessageBox(NULL,"Can't Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								
	}

	if (!(hRC=wglCreateContext(hDC)))				
	{
		KillGLWindow();								
		MessageBox(NULL,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								
	}

	if(!wglMakeCurrent(hDC,hRC))					
	{
		KillGLWindow();								
		MessageBox(NULL,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								
	}

	ShowWindow(hWnd,SW_SHOW);						
	SetForegroundWindow(hWnd);						
	SetFocus(hWnd);									
	ReSizeGLScene(width, height);					

	if (!InitGL())									
	{
		KillGLWindow();								
		MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								
	}

	return TRUE;									
}

LRESULT CALLBACK WndProc(	HWND	hWnd,			
							UINT	uMsg,			
							WPARAM	wParam,			
							LPARAM	lParam)			
{
	switch (uMsg)									
	{
		case WM_ACTIVATE:							
		{
			if (!HIWORD(wParam))					
			{
				active=TRUE;						
			}
			else
			{
				active=FALSE;						
			}

			return 0;								
		}

		case WM_SYSCOMMAND:							
		{
			switch (wParam)							
			{
				case SC_SCREENSAVE:					
				case SC_MONITORPOWER:				
				return 0;							
			}
			break;									
		}

		case WM_CLOSE:								
		{
			PostQuitMessage(0);						
			return 0;								
		}

		case WM_KEYDOWN:							
		{
			keys[wParam] = TRUE;					
			return 0;								
		}

		case WM_KEYUP:								
		{
			keys[wParam] = FALSE;					
			return 0;								
		}

		case WM_SIZE:								
		{
			ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));  
			return 0;								
		}
	}

	
	return DefWindowProc(hWnd,uMsg,wParam,lParam);
}

int WINAPI WinMain(	HINSTANCE	hInstance,			
					HINSTANCE	hPrevInstance,		
					LPSTR		lpCmdLine,			
					int			nCmdShow)			
{
	MSG		msg;									
	BOOL	done=FALSE;								

	
	if (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDNO)
	{
		fullscreen=FALSE;							
	}

	
	if (!CreateGLWindow("NeHe's OpenGL Framework",640,480,16,fullscreen))
	{
		return 0;									
	}

	while(!done)									
	{
		if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))	
		{
			if (msg.message==WM_QUIT)				
			{
				done=TRUE;							
			}
			else									
			{
				TranslateMessage(&msg);				
				DispatchMessage(&msg);				
			}
		}
		else										
		{
			
			if (active)								
			{
				if (keys[VK_ESCAPE])				
				{
					done=TRUE;						
				}
				else								
				{
					DrawGLScene();					
					SwapBuffers(hDC);				
				}
			}

			if (keys[VK_F1])						
			{
				keys[VK_F1]=FALSE;					
				KillGLWindow();						
				fullscreen=!fullscreen;				
				
				if (!CreateGLWindow("NeHe's OpenGL Framework",640,480,16,fullscreen))
				{
					return 0;						
				}
			}
		}
	}

	
	KillGLWindow();									
	return (msg.wParam);							
}

[zhouzhipen]

是Release 版的还是 Debug版的. Debug版的就没有什么解释的了.

Release版的,要么就是编译器,要么就是GL库有问题.

[tkminigame]

这算好的了，我跑个官方ogre的最简单的例子都占了40几兆，渲染两个模型一共8000多个三角形就50几兆了。

[seaboy100]

回4楼，当然是release版的，这个我在主楼里就说明了。
回5楼，那就是说我这样也算正常？
回6楼，你意思是说用directx也是占用几十兆内存吗？这样看来是与opengl和directx的硬件驱动有关了？

[pady_pady]

顶下,可能是它们内核分配的内存比较多,