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C++ Opengl, unresolved externals after linking libraries

3 posts in this topic

Hey all, this is my first post so I'll make it quick.
I currently have a problem in C++ where, after I compile, it prints an error in the console saying:

------ Build started: Project: OpenGL_1, Configuration: Debug Win32 ------
1> CreatingAWindow.cpp
1>CreatingAWindow.obj : error LNK2019: unresolved external symbol "void __cdecl EnableOpenGL(struct HWND__ *,struct HDC__ * *,struct HGLRC__ * *)" (?EnableOpenGL@@YAXPAUHWND__@@PAPAUHDC__@@PAPAUHGLRC__@@@Z) referenced in function _WinMain@16
1>C:\Users\MindOfCorruption97\Desktop\MyStuff\Programming\C++\SDL_OpenGL\Sandbox\OpenGL_1\Debug\OpenGL_1.exe : fatal error LNK1120: 1 unresolved externals

I linked the libraries because before the error was much larger.
After I linked the libraries there was only one error message left as you can see above.
Here is the code if you guys need it:

[source lang="cpp"]#include <windows.h>
#include <gl/gl.h>

//Function that handles messages sent to your window.
//hwnd is the handle to the window, uMsg is the message code, wParam and lParam contains more code about the message.
void EnableOpenGL(HWND hwnd,HDC * hdc,HGLRC * hrc);
void DisableOpenGL(HWND hwnd,HDC hdc,HGLRC hrc);

//wWinMain is the Main method in a windows C++ program.
//hinstance is called "handle to an instance" or "handle to a module". It is used to identify the EXE.
//nCmdLine contains command line arguments. nCmdShow chooses whether it is minimized, maximized, or hidden.
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int iCmdShow)
HWND hwnd;
HDC hdc;
HGLRC hrc;
MSG msg;
BOOL quit = FALSE;
float theta = 0.0f;

wc.style = CS_OWNDC;
wc.lpfnWndProc = WndProc; //Pointer to the Window Procedure(WindowProc).
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;//hInstance is used to handle the application instance.
wc.hIcon = LoadIcon(NULL,IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL,IDC_ARROW);
wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
wc.lpszMenuName = NULL;
wc.lpszClassName = "GLSample";//lpszClassName is a string that identifies the window class.
RegisterClass(&wc);//Uses the OS to register the window.

//Creates a new instance of the window.CreateWindowEx(Window style,Type of window,Title bar).
//WS_OVERLAPPEDWINDOW give the window a title bar and all that stuff.
hwnd = CreateWindow(
"GLSample","OPENGL Window Creation",


//Used to dispatch messages to the correct windows.
if(msg.message == WM_QUIT)
quit = TRUE;
TranslateMessage(&msg);//Used to translate keyboard input.
DispatchMessage(&msg);//Returns the message for the next loop.

glColor3f(1.0f,0.0f,0.0f); glVertex2f(0.0f,1.0f);
glColor3f(0.0f,0.0f,1.0f); glVertex2f(0.87f,-0.5f);
glColor3f(0.0f,0.0f,1.0f); glVertex2f(-0.87f,-0.5f);


theta += 1.0f;

return msg.wParam;

case WM_CREATE:return 0;
case WM_CLOSE:PostQuitMessage(0);return 0;
case WM_DESTROY:return 0;
return 0;
return 0;
default:return DefWindowProc(hwnd,uMsg,wParam,lParam);

void EnableOpenGl(HWND hwnd,HDC * hdc,HGLRC * hrc)
int format;

*hdc = GetDC(hwnd);

pfd.nSize = sizeof(pfd);
pfd.nVersion = 1;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = 24;
pfd.cDepthBits = 16;
pfd.iLayerType = PFD_MAIN_PLANE;
format = ChoosePixelFormat(*hdc,&pfd);

*hrc = wglCreateContext(*hdc);
void DisableOpenGL(HWND hwnd,HDC hdc,HGLRC hrc)
Help as soon as possible, thank you.

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At the top, you declare EnableOpenGL, but your implementation of it near the bottom of the code is called EnableOpenGl (note the lowercase l).

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[quote name='FLeBlanc' timestamp='1352246182' post='4998266'] At the top, you declare EnableOpenGL, but your implementation of it near the bottom of the code is called EnableOpenGl (note the lowercase l). [/quote] [quote name='NumberXaero' timestamp='1352246247' post='4998267'] void EnableOpenGL(HWND hwnd,HDC * hdc,HGLRC * hrc); <-- BIG L end of file void EnableOpenGl(HWND hwnd,HDC * hdc,HGLRC * hrc) <-- little l [/quote]

Thank you, I never knew that the problem was so simple.
Now it works great. [img]http://public.gamedev.net//public/style_emoticons/default/smile.png[/img]

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