Cannot convert 'LPCWSTR {aka const wchar_t *}' to 'LPCSTR {aka const char *}

Question

I am trying to get Glew and opengl 3.2 working with blocks of code (minGW) in the context of win32. i found a nice little tutorial here

As I was trying to understand, if compiling glew in code blocks was really possible, I wanted to try the source before doing the tutorial to see if this would work.

after a slight improvement in the code, I tried to compile and got some errors that I had never seen before. they look like this

|In function 'bool createWindow(LPCWSTR, int, int)':| |73|error: cannot convert 'LPCWSTR {aka const wchar_t*}' to 'LPCSTR {aka const char*}' in assignment| |80|error: cannot convert 'LPCWSTR {aka const wchar_t*}' to 'LPCSTR {aka const char*}' for argument '2' to 'HWND__* CreateWindowExA(DWORD, LPCSTR, LPCSTR, DWORD, int, int, int, int, HWND, HMENU, HINSTANCE, LPVOID)'| |In function 'int WinMain(HINSTANCE, HINSTANCE, LPSTR, int)':| |105|warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]| |110|error: '_TRUNCATE' was not declared in this scope| |110|error: 'mbstowcs_s' was not declared in this scope| 

My code

 include <iostream> #include <Windows.h> #ifndef GLEW_STATIC #define GLEW_STATIC #endif //GLEW_STATIC #include <GL/glew.h> #include <GL/wglew.h> //using namespace std; // //int main() //{ // cout << "Hello world!" << endl; // return 0; //} #include "opengl_3.h" OpenGLContext openglContext; // Our OpenGL Context class bool running = true; // Whether or not the application is currently running HINSTANCE hInstance; // The HINSTANCE of this application LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); // Standard window callback /** WndProc is a standard method used in Win32 programming for handling Window messages. Here we handle our window resizing and tell our OpenGLContext the new window size. */ LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) { switch (message) { case WM_SIZE: // If our window is resizing { openglContext.reshapeWindow(LOWORD(lParam), HIWORD(lParam)); // Send the new window size to our OpenGLContext break; } case WM_DESTROY: { PostQuitMessage(0); break; } } return DefWindowProc(hWnd, message, wParam, lParam); } /** createWindow is going to create our window using Windows API calls. It is then going to create our OpenGL context on the window and then show our window, making it visible. */ bool createWindow(LPCWSTR title, int width, int height) { WNDCLASS windowClass; HWND hWnd; DWORD dwExStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; hInstance = GetModuleHandle(NULL); windowClass.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; windowClass.lpfnWndProc = (WNDPROC) WndProc; windowClass.cbClsExtra = 0; windowClass.cbWndExtra = 0; windowClass.hInstance = hInstance; windowClass.hIcon = LoadIcon(NULL, IDI_WINLOGO); windowClass.hCursor = LoadCursor(NULL, IDC_ARROW); windowClass.hbrBackground = NULL; windowClass.lpszMenuName = NULL; windowClass.lpszClassName = title; if (!RegisterClass(&windowClass)) { return false; } hWnd = CreateWindowEx(dwExStyle, title, title, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0, width, height, NULL, NULL, hInstance, NULL); openglContext.create30Context(hWnd); // Create our OpenGL context on the given window we just created ShowWindow(hWnd, SW_SHOW); UpdateWindow(hWnd); return true; } /** WinMain is the main entry point for Windows based applications as opposed to 'main' for console applications. Here we will make the calls to create our window, setup our scene and then perform our 'infinite' loop which processes messages and renders. */ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { MSG msg; /** The following 6 lines of code do conversion between char arrays and LPCWSTR variables which are used in the Windows API. */ char *orig = "OpenGL 3 Project"; // Our windows title size_t origsize = strlen(orig) + 1; const size_t newsize = 100; size_t convertedChars = 0; wchar_t wcstring[newsize]; mbstowcs_s(&convertedChars, wcstring, origsize, orig, _TRUNCATE); createWindow(wcstring, 500, 500); // Create our OpenGL window openglContext.setupScene(); // Setup our OpenGL scene /** This is our main loop, it continues for as long as running is true */ while (running) { if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { // If we have a message to process, process it if (msg.message == WM_QUIT) { running = false; // Set running to false if we have a message to quit } else { TranslateMessage(&msg); DispatchMessage(&msg); } } else { // If we don't have a message to process openglContext.renderScene(); // Render our scene (which also handles swapping of buffers) } } return (int) msg.wParam; } 

(Sorry for the text wall) there are other files, but all the errors seem to get from here. bad post if necessary.

I really did not see any errors like this, so I did some search queries and found out that the error was caused because the compiler is not configured for multibyte (parameter in VS2010). I looked around a bit and could not find such settings in the code blocks. Is this code used only in VS or am I missing something? I was worried that this could be due to my connection due to the fact that I had a lot of problems with this in the past. Any help would be appreciated.

Answer 1

Change CreateWindowEx to CreateWindowExW or define a UNICODE macro before including any headers.

Answer 2

I have never used minGW, so take this with lots of salt. (VS Express can be used, BTW.)

The Unicode / Ascii solution is heavily controlled by the UNICODE definition. Therefore, if you #define UNICODE 1 or perhaps pass this on your command line, you have a good chance to solve your problem.