Display: C/C++ Version

The C/C++ version of Display uses CreateWindowEx() instead of CreateWindow() to create the 800x600 borderless window. Further, it calls ShowWindow() in the WM_CREATE handler to make the window visible before calling fg_modetest() or fg_modeset().

/****************************************************************************\
*                                                                            *
*  Display.c                                                                 *
*                                                                            *
*  This program resizes the desktop to 800x600 using the fg_modeset()        *
*  function.                                                                 *
*                                                                            *
\****************************************************************************/
#include <fgwin.h>
#define vbWidth  800
#define vbHeight 600
LRESULT CALLBACK WindowProc(HWND,UINT,WPARAM,LPARAM);
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdParam, int iCmdShow)
{
   static char szAppName[] = "FGdisplay";
   HWND        hWnd;
   MSG         msg;
   WNDCLASSEX  wndclass;
   wndclass.cbSize        = sizeof(wndclass);
   wndclass.style         = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
   wndclass.lpfnWndProc   = WindowProc;
   wndclass.cbClsExtra    = 0;
   wndclass.cbWndExtra    = 0;
   wndclass.hInstance     = hInstance;
   wndclass.hIcon         = LoadIcon(NULL,IDI_APPLICATION);
   wndclass.hCursor       = LoadCursor(NULL,IDC_ARROW);
   wndclass.hbrBackground = NULL;
   wndclass.lpszMenuName  = NULL;
   wndclass.lpszClassName = szAppName;
   wndclass.hIconSm       = LoadIcon(NULL,IDI_APPLICATION);
   RegisterClassEx(&wndclass);
   hWnd = CreateWindowEx(
      WS_EX_TOPMOST,           // extended window style
      szAppName,               // window class name
      "Change Display Settings", // window caption
      WS_POPUP,                // window style
      0,                       // initial x position
      0,                       // initial y position
      vbWidth,                 // initial x size
      vbHeight,                // initial y size
      NULL,                    // parent window handle
      NULL,                    // window menu handle
      hInstance,               // program instance handle
      NULL);                   // creation parameters
   ShowWindow(hWnd,iCmdShow);
   UpdateWindow(hWnd);
   while (GetMessage(&msg,NULL,0,0))
   {
      TranslateMessage(&msg);
      DispatchMessage(&msg);
   }
   return msg.wParam;
}
/****************************************************************************\
*                                                                            *
*  WindowProc()                                                              *
*                                                                            *
\****************************************************************************/
HDC      hDC;
HPALETTE hPal;
int      hVB;
LRESULT CALLBACK WindowProc(HWND hWnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
   PAINTSTRUCT ps;
   switch (iMsg)
   {
      case WM_CREATE:
         ShowWindow(hWnd,SW_SHOWNORMAL);
         if (fg_modetest(vbWidth,vbHeight,fg_colors()) != 0)
         {
            MessageBox(hWnd,"Cannot set 800x600 desktop","Error",MB_OK|MB_ICONSTOP);
            DestroyWindow(hWnd);
            return 0;
         }
         fg_modeset(vbWidth,vbHeight,fg_colors(),1);
         hDC = GetDC(hWnd);
         fg_setdc(hDC);
         hPal = fg_defpal();
         fg_realize(hPal);
         fg_vbinit();
         hVB = fg_vballoc(vbWidth,vbHeight);
         fg_vbopen(hVB);
         fg_vbcolors();
         fg_setcolor(19);
         fg_fillpage();
         return 0;
      case WM_KEYDOWN:
         switch(wParam)
         {
            case VK_ESCAPE:
            case VK_F12:
               DestroyWindow(hWnd);
               break;
         }
         return 0;
      case WM_PAINT:
         BeginPaint(hWnd,&ps);
         fg_vbpaste(0,vbWidth-1,0,vbHeight-1,0,vbHeight-1);
         EndPaint(hWnd,&ps);
         return 0;
      case WM_SETFOCUS:
         fg_realize(hPal);
         InvalidateRect(hWnd,NULL,TRUE);
         return 0;
      case WM_DESTROY:
         fg_vbclose();
         fg_vbfree(hVB);
         fg_vbfin();
         DeleteObject(hPal);
         ReleaseDC(hWnd,hDC);
         fg_modeset(0,0,0,0);
         PostQuitMessage(0);
         return 0;
   }
   return DefWindowProc(hWnd,iMsg,wParam,lParam);
}