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keikei_c

openGl errors!

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Hi! I've been running some opengl codes in C++ for some time now and never had some errors viewing them. but the codes from the tutorial at hene is not running! beginning from Lesson 1, etc! I have found these errors: --------------------Configuration: Lesson1 - Win32 Debug-------------------- Linking... Lesson1.obj : error LNK2001: unresolved external symbol _gluPerspective@32 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glLoadIdentity@0 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glMatrixMode@4 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glViewport@16 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glHint@8 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glDepthFunc@4 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glEnable@4 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glClearDepth@8 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glClearColor@16 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glShadeModel@4 Lesson1.obj : error LNK2001: unresolved external symbol __imp__glClear@4 Lesson1.obj : error LNK2001: unresolved external symbol __imp__wglDeleteContext@4 Lesson1.obj : error LNK2001: unresolved external symbol __imp__wglMakeCurrent@8 Lesson1.obj : error LNK2001: unresolved external symbol __imp__wglCreateContext@4 LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main Debug/Lesson1.exe : fatal error LNK1120: 15 unresolved externals Error executing link.exe. Lesson1.exe - 16 error(s), 0 warning(s) ___________________ It seems as if its not compatible..i've checked the libraries and include files as well as the .dll files and they were all there.. if not, I couldn't have run other codes.. HELP! I NEED TO LEARN THINGS FAST FOR OUR THESIS!!! thanks!

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you need to link the opengl library. assuming visual c++, project properties -> linker -> additional libraries(i think), add opengl32.lib. another way to link is by adding #pragma comment(lib, "opengl32.lib").

the last link error is throwing me off... i'm guessing there should be a winmain rather than main.

edit: oh, and i believe "glu32.lib" is right name for the glu library. don't forget that too. (didn't see the gluPerspective)

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You're not linking to the libraries you need to. I think these are: opengl32, glu32, and maybe gdi32 or something.

Quote:
Original post by keikei_c
HELP! I NEED TO LEARN THINGS FAST FOR OUR THESIS!!!


That's your problem, not ours.

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Thanks all for your help. I forgot to tell you that I already did that beforehand and still found errors.

--------------------Configuration: Lesson1 - Win32 Debug--------------------
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/Lesson1.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

Lesson1.exe - 2 error(s), 0 warning(s)

------
It's weird because I never really do some linking with other OpenGl programs I run..only those from HeNe..

Quote:
Original post by RAZORUNREAL

That's your problem, not ours.


Did I say that it's YOUR PROBLEM? In case you haven't noticed, I actually asked for help here, as normal humans would ask for help when they need it. I am not passing the labor onto you. If you cannot be so humane with treating beginners and cannot stop flaunting about what your brain has, then DON'T POST and DON'T HELP!

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here's a copy of the code..taken this from hene.gamedev.net

/*
* 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> // 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

HDC hDC=NULL; // Private GDI Device Context
HGLRC hRC=NULL; // Permanent Rendering Context
HWND hWnd=NULL; // Holds Our Window Handle
HINSTANCE hInstance; // Holds The Instance Of The Application

bool keys[256]; // Array Used For The Keyboard Routine
bool active=TRUE; // Window Active Flag Set To TRUE By Default
bool fullscreen=TRUE; // Fullscreen Flag Set To Fullscreen Mode By Default

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); // Declaration For WndProc

GLvoid 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); // Enable Smooth Shading
glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background
glClearDepth(1.0f); // Depth Buffer Setup
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing 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 Screen And Depth Buffer
glLoadIdentity(); // Reset The Current Modelview Matrix
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
}
}

/* This Code Creates Our OpenGL Window. Parameters Are: *
* title - Title To Appear At The Top Of The Window *
* width - Width Of The GL Window Or Fullscreen Mode *
* height - Height Of The GL Window Or Fullscreen Mode *
* bits - Number Of Bits To Use For Color (8/16/24/32) *
* fullscreenflag - Use Fullscreen Mode (TRUE) Or Windowed Mode (FALSE) */

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 Size, 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; // 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 Use Windowed Mode.
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; // Windowed Mode Selected. 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; // 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

// Create The Window
if (!(hWnd=CreateWindowEx( dwExstyle, // Extended style For The Window
"OpenGL", // Class Name
title, // Window Title
dwstyle | // Defined Window style
WS_CLIPSIBLINGS | // Required Window style
WS_CLIPCHILDREN, // Required Window style
0, 0, // Window Position
WindowRect.right-WindowRect.left, // Calculate Window Width
WindowRect.bottom-WindowRect.top, // Calculate Window Height
NULL, // No Parent Window
NULL, // No Menu
hInstance, // Instance
NULL))) // Dont 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("NeHe's OpenGL Framework",640,480,16,fullscreen))
{
return 0; // Quit If Window Was Not Created
}

while(!done) // Loop That Runs While done=FALSE
{
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("NeHe's OpenGL Framework",640,480,16,fullscreen))
{
return 0; // Quit If Window Was Not Created
}
}
}
}

// Shutdown
KillGLWindow(); // Kill The Window
return (msg.wParam); // Exit The Program
}
---------

thanks for the help :)

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Since you're using NeHe's code, why don't you take some time to read the tutorials. The very first one tells you exactly what you need to do. It will tell you what you did wrong about the unresolved external symbols (all of them). It is a very common error, and the tutorial is very clear what to do if you just take the time to actually read it.

Clicky. Read the fifth paragraph.

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Quote:
Original post by gumpy macdrunken

the last link error is throwing me off... i'm guessing there should be a winmain rather than main.


thanks for giving me the idea..I solved it! I need to set it as a win32 application, and I failed to do that. Thanks!!!

http://vcfaq.mvps.org/lang/5.htm

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Quote:
Original post by Brother Bob
Since you're using NeHe's code, why don't you take some time to read the tutorials. The very first one tells you exactly what you need to do. It will tell you what you did wrong about the unresolved external symbols (all of them). It is a very common error, and the tutorial is very clear what to do if you just take the time to actually read it.

Clicky. Read the fifth paragraph.


yeah, i read that..the problem is i really didn't understand what win32 application means before or how to do that..hehehe..thanks!!! btw, is there a way for me to link the libraries right on and not type them at the settings after every compilation?

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Quote:
Original post by keikei_c
Thanks all for your help. I forgot to tell you that I already did that beforehand and still found errors.

--------------------Configuration: Lesson1 - Win32 Debug--------------------
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/Lesson1.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

Lesson1.exe - 2 error(s), 0 warning(s)

------
It's weird because I never really do some linking with other OpenGl programs I run..only those from HeNe..
What kind of application did you choose when you made the project? It sounds like you've chosen a Console application, while you should have chosen a Windows Application (assuming VC++, this option is located under settings in the New Project dialog)

[EDIT]Obviously solved allready, lol... Regarding your new question: yes, that can be done. It is highly compiler-dependant though.
Try googling "<compiler name> linking external libraries[/EDIT]

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Quote:
Original post by keikei_c
btw, is there a way for me to link the libraries right on and not type them at the settings after every compilation?

Yes there is, and it says in the tutorial I just linked to, and in the (surprise) fifth paragraph.
Quote:

In Visual C++ go to Project, Settings, and then click on the LINK tab. Under "Object/Library Modules" at the beginning of the line (before kernel32.lib) add OpenGL32.lib GLu32.lib and GLaux.lib. Once you've done this click on OK.

You don't have to do that for every compilation, only when you create the project. You don't create a new project each time you want to compile your code, do you?

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