Computer Science Final Project
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
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!
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:
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:
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
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]
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).
Thanks again! It works great know (just got to fool around with the rotation values to make it look good).
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