Computer Science Final Project

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23 comments, last by Erunama 21 years, 11 months ago
Since you posted the code, can you do us all a favor and zip your whole project and put it up somewhere so that we won''t have to mess with files, project settings and the such?
---visit #directxdev on afternet <- not just for directx, despite the name
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Enurama, the code above is not for you to use in your project. It was just to demonstrate the use of glPushMatrix() and glPopMatrix().

And, definatelly, you WILL NEED to use them, as you want some vertices to be rotated (the cube) and others to be static (the room).

The For loop just gives an increasing number... this way you could copy/past that code in a OpenGL basecode and see what I mean.

Definatelly, LEARN glPushMatrix() and glPopMatrix().

Bye!
Ok, for anyone who wanted the project files, here you go:
http://opengl.0catch.com/final_project.zip

(I just registered for a ZeroCatch account... I am surprised that the opengl username was not taken). Just a note, I am using Microsoft Visual C++ version 4. I am not sure whether or not the project files will work on the newer versions, but at the very least, you''ll get the necessary source and header files (if the workspace does not work, just go in and link to the OGL libraries, then include apvector.cpp and cube.cpp to your workspace).

ChacaL: I will learn Push and Pop eventually, but I have no need for them yet. This program can work without them (I know because I did it without classes). I don''t see the reason of putting something in there that I do not need and do not fully understand. If you want proof that this scenario works without glPushMatrix and glPopMatrix, check out my old code:


  #include <windows.h>								// Header File For Windows#include <gl\gl.h>								// Header File For The OpenGL32 Library#include <gl\glu.h>								// Header File For The GLu32 Library#include <gl\glaux.h>								// Header File For The GLaux Library#include "cube.h"								// Header file for the Cube class#include "apvector.h"							// Header file for the AP vector classHGLRC		hRC=NULL;							// Permanent Rendering ContextHDC		hDC=NULL;							// Private GDI Device ContextHWND		hWnd=NULL;							// Holds Our Window HandleHINSTANCE	hInstance;							// Holds The Instance Of The ApplicationBOOL	keys[256];								// Array Used For The Keyboard RoutineBOOL	active=TRUE;								// Window Active Flag Set To TRUE By DefaultBOOL	fullscreen=TRUE;							// Fullscreen Flag Set To Fullscreen Mode By DefaultGLfloat cuberot;							// Rotation angle for the spinning cubeLRESULT	CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);				// Declaration For WndProcGLvoid ReSizeGLScene(GLsizei width, GLsizei height)				// Resize And Initialize The GL Window{	if (height==0)								// Prevent A Divide By Zero By	{		height=1;							// Making Height Equal One	}	glViewport(0, 0, width, height);					// Reset The Current Viewport	glMatrixMode(GL_PROJECTION);						// Select The Projection Matrix	glLoadIdentity();							// Reset The Projection Matrix	// Calculate The Aspect Ratio Of The Window	gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);	glMatrixMode(GL_MODELVIEW);						// Select The Modelview Matrix	glLoadIdentity();							// Reset The Modelview Matrix}int InitGL(GLvoid)								// All Setup For OpenGL Goes Here{	glShadeModel(GL_SMOOTH);						// Enables Smooth Shading	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);					// Black Background	glClearDepth(1.0f);							// Depth Buffer Setup	glEnable(GL_DEPTH_TEST);						// Enables Depth Testing	glDepthFunc(GL_LEQUAL);							// The Type Of Depth Test To Do	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);			// Really Nice Perspective Calculations	return TRUE;								// Initialization Went OK}int DrawGLScene(GLvoid)								// Here''s Where We Do All The Drawing{	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);			// Clear The Screen And The Depth Buffer	glLoadIdentity();							// Reset The Current Modelview Matrix	glTranslatef(0.0f,-3.0f,-10.0f);	// Move into the screen a down a little bit	// Draw the room	glBegin(GL_QUADS);		glColor3f(0.5f,0.5f,0.5f);		// Set color for walls (grey)		// Draw left wall first		glVertex3f(-3.0f,5.0f,6.0f);		glVertex3f(-3.0f,0.0f,6.0f);		glVertex3f(-3.0f,0.0f,-5.0f);		glVertex3f(-3.0f,5.0f,-5.0f);		// Draw right wall next		glVertex3f(3.0f,5.0f,6.0f);		glVertex3f(3.0f,0.0f,6.0f);		glVertex3f(3.0f,0.0f,-5.0f);		glVertex3f(3.0f,5.0f,-5.0f);		// Draw back wall next		glVertex3f(-3.0f,5.0f,-5.0f);		glVertex3f(-3.0f,0.0f,-5.0f);		glVertex3f(3.0f,0.0f,-5.0f);		glVertex3f(3.0f,5.0f,-5.0f);		// Fourth wall is not needed (behind screen)		glColor3f(0.3f,0.3f,0.3f);		// Set color for ceiling and floor (dark grey)		// Draw ceiling		glVertex3f(-3.0f,5.0f,6.0f);		glVertex3f(-3.0f,5.0f,-5.0f);		glVertex3f(3.0f,5.0f,-5.0f);		glVertex3f(3.0f,5.0f,6.0f);		// Draw floor		glVertex3f(-3.0f,0.0f,6.0f);		glVertex3f(-3.0f,0.0f,-5.0f);		glVertex3f(3.0f,0.0f,-5.0f);		glVertex3f(3.0f,0.0f,6.0f);	glEnd();	glLoadIdentity();		// Move to the center of the screen and reset the axis	glTranslatef(0.0f,-0.5f,-5.0f);		// Move to the center of the room	glRotatef(cuberot,1.0f,1.0f,0.0f);	// Rotate the cube along the X and Y axis	// After the room, draw the rotating cube	glBegin(GL_QUADS);		glColor3f(0.1f,0.1f,1.0f);		// Make the cube blue				// Draw the left side of the cube		glVertex3f(0.5f,0.5f,0.5f);		glVertex3f(0.5f,-0.5f,0.5f);		glVertex3f(0.5f,-0.5f,-0.5f);		glVertex3f(0.5f,0.5f,-0.5f);		// Draw the right side of the cube		glVertex3f(-0.5f,0.5f,0.5f);		glVertex3f(-0.5f,-0.5f,0.5f);		glVertex3f(-0.5f,-0.5f,-0.5f);		glVertex3f(-0.5f,0.5f,-0.5f);				// Draw the back of the cube		glVertex3f(0.5f,0.5f,-0.5f);		glVertex3f(0.5f,-0.5f,-0.5f);		glVertex3f(-0.5f,-0.5f,-0.5f);		glVertex3f(-0.5f,0.5f,-0.5f);		// Draw the front of the cube		glVertex3f(0.5f,0.5f,0.5f);		glVertex3f(0.5f,-0.5f,0.5f);		glVertex3f(-0.5f,-0.5f,0.5f);		glVertex3f(-0.5f,0.5f,0.5f);		// Draw the top of the cube		glVertex3f(0.5f,0.5f,0.5f);		glVertex3f(0.5f,0.5f,-0.5f);		glVertex3f(-0.5f,0.5f,-0.5f);		glVertex3f(-0.5f,0.5f,0.5f);		// Draw the bottom of the cube		glVertex3f(0.5f,-0.5f,0.5f);		glVertex3f(0.5f,-0.5f,-0.5f);		glVertex3f(-0.5f,-0.5f,-0.5f);		glVertex3f(-0.5f,-0.5f,0.5f);	glEnd();	cuberot += 0.2f;		// Change the angle of rotation (so that the cube actually rotates)	return TRUE;								// Everything Went OK}GLvoid KillGLWindow(GLvoid)							// Properly Kill The Window{	if (fullscreen)								// Are We In Fullscreen Mode?	{		ChangeDisplaySettings(NULL,0);					// If So Switch Back To The Desktop		ShowCursor(TRUE);						// Show Mouse Pointer	}	if (hRC)								// Do We Have A Rendering Context?	{		if (!wglMakeCurrent(NULL,NULL))					// Are We Able To Release The DC And RC Contexts?		{			MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		}		if (!wglDeleteContext(hRC))					// Are We Able To Delete The RC?		{			MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		}		hRC=NULL;							// Set RC To NULL	}	if (hDC && !ReleaseDC(hWnd,hDC))					// Are We Able To Release The DC	{		MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		hDC=NULL;							// Set DC To NULL	}	if (hWnd && !DestroyWindow(hWnd))					// Are We Able To Destroy The Window?	{		MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		hWnd=NULL;							// Set hWnd To NULL	}	if (!UnregisterClass("OpenGL",hInstance))			// Are We Able To Unregister Class	{		MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);		hInstance=NULL;									// Set hInstance To NULL	}}BOOL CreateGLWindow(char* title, int width, int height, int bits, BOOL fullscreenflag){	GLuint		PixelFormat;						// Holds The Results After Searching For A Match	WNDCLASS	wc;							// Windows Class Structure	DWORD		dwExStyle;						// Window Extended Style	DWORD		dwStyle;						// Window Style	RECT WindowRect;							// Grabs Rectangle Upper Left / Lower Right Values	WindowRect.left=(long)0;						// Set Left Value To 0	WindowRect.right=(long)width;						// Set Right Value To Requested Width	WindowRect.top=(long)0;							// Set Top Value To 0	WindowRect.bottom=(long)height;						// Set Bottom Value To Requested Height	fullscreen=fullscreenflag;						// Set The Global Fullscreen Flag	hInstance		= GetModuleHandle(NULL);			// Grab An Instance For Our Window	wc.style		= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;		// Redraw On Move, And Own DC For Window	wc.lpfnWndProc		= (WNDPROC) WndProc;				// WndProc Handles Messages	wc.cbClsExtra		= 0;						// No Extra Window Data	wc.cbWndExtra		= 0;						// No Extra Window Data	wc.hInstance		= hInstance;					// Set The Instance	wc.hIcon		= LoadIcon(NULL, IDI_WINLOGO);			// Load The Default Icon	wc.hCursor		= LoadCursor(NULL, IDC_ARROW);			// Load The Arrow Pointer	wc.hbrBackground	= NULL;						// No Background Required For GL	wc.lpszMenuName		= NULL;						// We Don''t Want A Menu	wc.lpszClassName	= "OpenGL";					// Set The Class Name	if (!RegisterClass(&wc))						// Attempt To Register The Window Class	{		MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;							// Exit And Return FALSE	}	if (fullscreen)								// Attempt Fullscreen Mode?	{		DEVMODE dmScreenSettings;					// Device Mode		memset(&dmScreenSettings,0,sizeof(dmScreenSettings));		// Makes Sure Memory''s Cleared		dmScreenSettings.dmSize=sizeof(dmScreenSettings);		// Size Of The Devmode Structure		dmScreenSettings.dmPelsWidth	= width;			// Selected Screen Width		dmScreenSettings.dmPelsHeight	= height;			// Selected Screen Height		dmScreenSettings.dmBitsPerPel	= bits;				// Selected Bits Per Pixel		dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;		// Try To Set Selected Mode And Get Results.  NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar.		if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL)		{			// If The Mode Fails, Offer Two Options.  Quit Or Run In A Window.			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;				// Select Windowed Mode (Fullscreen=FALSE)			}			else			{				// Pop Up A Message Box Letting User Know The Program Is Closing.				MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP);				return FALSE;					// Exit And Return FALSE			}		}	}	if (fullscreen)								// Are We Still In Fullscreen Mode?	{		dwExStyle=WS_EX_APPWINDOW;					// Window Extended Style		dwStyle=WS_POPUP;						// Windows Style		ShowCursor(FALSE);						// Hide Mouse Pointer	}	else	{		dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;			// Window Extended Style		dwStyle=WS_OVERLAPPEDWINDOW;					// Windows Style	}	AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);		// Adjust Window To True Requested Size	if (!(hWnd=CreateWindowEx(	dwExStyle,				// Extended Style For The Window					"OpenGL",				// Class Name					title,					// Window Title					WS_CLIPSIBLINGS |			// Required Window Style					WS_CLIPCHILDREN |			// Required Window Style					dwStyle,				// Selected Window Style					0, 0,					// Window Position					WindowRect.right-WindowRect.left,	// Calculate Adjusted Window Width					WindowRect.bottom-WindowRect.top,	// Calculate Adjusted Window Height					NULL,					// No Parent Window					NULL,					// No Menu					hInstance,				// Instance					NULL)))					// Don''t Pass Anything To WM_CREATE	{		KillGLWindow();							// Reset The Display		MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;							// Return FALSE	}	static	PIXELFORMATDESCRIPTOR pfd=					// pfd Tells Windows How We Want Things To Be	{		sizeof(PIXELFORMATDESCRIPTOR),					// Size Of This Pixel Format Descriptor		1,								// Version Number		PFD_DRAW_TO_WINDOW |						// Format Must Support Window		PFD_SUPPORT_OPENGL |						// Format Must Support OpenGL		PFD_DOUBLEBUFFER,						// Must Support Double Buffering		PFD_TYPE_RGBA,							// Request An RGBA Format		bits,								// Select Our Color Depth		0, 0, 0, 0, 0, 0,						// Color Bits Ignored		0,								// No Alpha Buffer		0,								// Shift Bit Ignored		0,								// No Accumulation Buffer		0, 0, 0, 0,							// Accumulation Bits Ignored		16,								// 16Bit Z-Buffer (Depth Buffer)		0,								// No Stencil Buffer		0,								// No Auxiliary Buffer		PFD_MAIN_PLANE,							// Main Drawing Layer		0,								// Reserved		0, 0, 0								// Layer Masks Ignored	};	if (!(hDC=GetDC(hWnd)))							// Did We Get A Device Context?	{		KillGLWindow();							// Reset The Display		MessageBox(NULL,"Can''t Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;							// Return FALSE	}	if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd)))				// Did Windows Find A Matching Pixel Format?	{		KillGLWindow();							// Reset The Display		MessageBox(NULL,"Can''t Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;							// Return FALSE	}	if(!SetPixelFormat(hDC,PixelFormat,&pfd))				// Are We Able To Set The Pixel Format?	{		KillGLWindow();							// Reset The Display		MessageBox(NULL,"Can''t Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;							// Return FALSE	}	if (!(hRC=wglCreateContext(hDC)))					// Are We Able To Get A Rendering Context?	{		KillGLWindow();							// Reset The Display		MessageBox(NULL,"Can''t Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;							// Return FALSE	}	if(!wglMakeCurrent(hDC,hRC))						// Try To Activate The Rendering Context	{		KillGLWindow();							// Reset The Display		MessageBox(NULL,"Can''t Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;							// Return FALSE	}	ShowWindow(hWnd,SW_SHOW);						// Show The Window	SetForegroundWindow(hWnd);						// Slightly Higher Priority	SetFocus(hWnd);								// Sets Keyboard Focus To The Window	ReSizeGLScene(width, height);						// Set Up Our Perspective GL Screen	if (!InitGL())								// Initialize Our Newly Created GL Window	{		KillGLWindow();							// Reset The Display		MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);		return FALSE;							// Return FALSE	}	return TRUE;								// Success}LRESULT CALLBACK WndProc(	HWND	hWnd,					// Handle For This Window				UINT	uMsg,					// Message For This Window				WPARAM	wParam,					// Additional Message Information				LPARAM	lParam)					// Additional Message Information{	switch (uMsg)								// Check For Windows Messages	{		case WM_ACTIVATE:						// Watch For Window Activate Message		{			if (!HIWORD(wParam))					// Check Minimization State			{				active=TRUE;					// Program Is Active			}			else			{				active=FALSE;					// Program Is No Longer Active			}			return 0;						// Return To The Message Loop		}		case WM_SYSCOMMAND:						// Intercept System Commands		{			switch (wParam)						// Check System Calls			{				case SC_SCREENSAVE:				// Screensaver Trying To Start?				case SC_MONITORPOWER:				// Monitor Trying To Enter Powersave?				return 0;					// Prevent From Happening			}			break;							// Exit		}		case WM_CLOSE:							// Did We Receive A Close Message?		{			PostQuitMessage(0);					// Send A Quit Message			return 0;						// Jump Back		}		case WM_KEYDOWN:						// Is A Key Being Held Down?		{			keys[wParam] = TRUE;					// If So, Mark It As TRUE			return 0;						// Jump Back		}		case WM_KEYUP:							// Has A Key Been Released?		{			keys[wParam] = FALSE;					// If So, Mark It As FALSE			return 0;						// Jump Back		}		case WM_SIZE:							// Resize The OpenGL Window		{			ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));		// LoWord=Width, HiWord=Height			return 0;						// Jump Back		}	}	// Pass All Unhandled Messages To DefWindowProc	return DefWindowProc(hWnd,uMsg,wParam,lParam);}int WINAPI WinMain(	HINSTANCE	hInstance,				// Instance			HINSTANCE	hPrevInstance,				// Previous Instance			LPSTR		lpCmdLine,				// Command Line Parameters			int		nCmdShow)				// Window Show State{	MSG	msg;								// Windows Message Structure	BOOL	done=FALSE;							// Bool Variable To Exit Loop	// Ask The User Which Screen Mode They Prefer	if (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDNO)	{		fullscreen=FALSE;						// Windowed Mode	}	// Create Our OpenGL Window	if (!CreateGLWindow("Dan Carroll''s Final Project",640,480,16,fullscreen))	{		return 0;							// Quit If Window Was Not Created	}	while(!done)								// Loop That Runs Until done=TRUE	{		if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))			// Is There A Message Waiting?		{			if (msg.message==WM_QUIT)				// Have We Received A Quit Message?			{				done=TRUE;					// If So done=TRUE			}			else							// If Not, Deal With Window Messages			{				TranslateMessage(&msg);				// Translate The Message				DispatchMessage(&msg);				// Dispatch The Message			}		}		else								// If There Are No Messages		{			// Draw The Scene.  Watch For ESC Key And Quit Messages From DrawGLScene()			if (active)						// Program Active?			{				if (keys[VK_ESCAPE])				// Was ESC Pressed?				{					done=TRUE;				// ESC Signalled A Quit				}				else						// Not Time To Quit, Update Screen				{					DrawGLScene();				// Draw The Scene					SwapBuffers(hDC);			// Swap Buffers (Double Buffering)				}			}			if (keys[VK_F1])					// Is F1 Being Pressed?			{				keys[VK_F1]=FALSE;				// If So Make Key FALSE				KillGLWindow();					// Kill Our Current Window				fullscreen=!fullscreen;				// Toggle Fullscreen / Windowed Mode				// Recreate Our OpenGL Window				if (!CreateGLWindow("Dan Carroll''s Final Project",640,480,16,fullscreen))				{					return 0;				// Quit If Window Was Not Created				}			}		}	}	// Shutdown	KillGLWindow();								// Kill The Window	return (msg.wParam);							// Exit The Program}  
Well, I solved it for you. It turned out that myAngle in Cube::Draw was 0 on every iteration, indicating that something reset your data structures. After some tracing, the problem is in this line:

        int DrawGLScene(apvector <Cube> cubes)								// Here's Where We Do All The Drawing    

You are passing cubes by value. Aside from performance penalty involved in copying the array, whatever your drawing function changed (myAngle, in this case) was changed in the local copy of the array. The "real" cubes array wasn't modified, and next time you drew it, you got the original array, instead of modified one. Changing the function declaration to

  int DrawGLScene(apvector <Cube>& cubes)								// Here's Where We Do All The Drawing        

solves the problem.

How did I find this bug? I noticed that myAngle is zero. I got its address and set data breakpoint on (float *)0x1234, where 0x1234 is the address of myAngle. The breakpoint was hit from debug free memory routine that was overwriting the container, which was called from apvector destructor. Naturally, I didn't expect vector destructor to be called in your render loop, and after some looking around I noticed that you were passing it by value instead of by reference.

Edit: gl[Push|Pop]Matrix wouldn't help in this case, because geometry modifications made during drawing weren't saved. Heh.

[edited by - IndirectX on May 4, 2002 5:19:35 PM]


[edited by - IndirectX on May 5, 2002 9:01:06 PM]
---visit #directxdev on afternet <- not just for directx, despite the name
I knew it would be something simple! Thank you for finding the error, IndirectX. I knew all along it would be some little error like that, which is why I was annoyed with everyone suggesting glPush and PopMatrix, because I was sure I didn''t need them.

Thanks again! It works great know (just got to fool around with the rotation values to make it look good).

This topic is closed to new replies.

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