Hi there,

I came across an issue with my rendering code. As the title says, I get no render output at specific window sizes. For example at 508x525 and less the expected output is visible, but at ~ 552x552 and higher it is not.
Here is my Code:
WndProc
Code cpp:
LRESULT CALLBACK Graphics::WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam){
    switch(msg){
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        case WM_SIZE:
            ResetViewport(LOWORD(lParam), HIWORD(lParam));
            break;
        case WM_KEYDOWN:
            int width = wndSize.iWidth;
            int height = wndSize.iHeight;
            break;
        default:
            return DefWindowProc(hWnd, msg, wParam, lParam);
            break;
    }
    return 0;
}

Init opengl function
Code cpp:
bool Graphics::InitGL(){
  // Window existing?
    if(!hMainWnd)
        return false;
 
    // Pixelformat
    PIXELFORMATDESCRIPTOR pfd;
    ZeroMemory(&pfd, sizeof(PIXELFORMATDESCRIPTOR));
 
    pfd.nVersion = 1;
    pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
    pfd.dwFlags = PFD_SUPPORT_OPENGL | PFD_DRAW_TO_WINDOW | PFD_DOUBLEBUFFER;
    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 24;
    pfd.cAlphaBits = 16;
    pfd.cDepthBits = 8;
 
    // Get the device context
    if(!(hDC = GetDC(hMainWnd)))
        return false;
 
    // Get appropriate pixel format
    int iFormat = 0;
    if(!(iFormat = ChoosePixelFormat(hDC, &pfd)))
        return false;
 
    if(!SetPixelFormat(hDC, iFormat, &pfd))
        return false;
 
    // Create render context
    if(!(hRC = wglCreateContext(hDC)))
        return false;
 
    // Make it the current context
    if(!wglMakeCurrent(hDC, hRC))
        return false;
 
 
    // set the viewport
    // get the client area size
    RECT clientArea;
    GetClientRect(hMainWnd, &clientArea);
    ResetViewport(clientArea.right - clientArea.left, clientArea.bottom - clientArea.top);
    return true;
}

ResetViewport function
Code cpp:
void Graphics::ResetViewport(int width, int height){
    if(width <= 0)
        width = 100;
    if(height <= 0)
        height = 100;
 
    wndSize.iWidth = width;
    wndSize.iHeight = height;
 
    glViewport(0, 0, width, height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0f, (float)(width/height), 0.1f, 100.0f);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

Render function
Code cpp:
void Graphics::Render(){
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glClearColor(1.0f, 0.15f, 0.76f, 1.0f);
 
    glLoadIdentity();
    glBegin(GL_TRIANGLES);
        glColor3f(1.0f, 1.0f, 1.0f);
        glVertex3f(0.0f, 0.0f, 0.0f);
        glVertex3f(0.5f, 1.0f, 0.0f);
        glVertex3f(1.0f, 0.0f, 0.0f);
    glEnd();
 
    SwapBuffers(hDC);
}

Any suggestions?

EDIT: Does anybody know why I can't change my profile settings?