#include <windows.h>


HWND hWnd=NULL;

bool bRegioned;


LRESULT CALLBACK WndProc(HWND hWnd, UINT uMessage, WPARAM wParam, LPARAM lParam);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, \
                   LPSTR lpCmdLine, int nCmdShow)
{

  WNDCLASS wndWc;

  wndWc.style = CS_OWNDC;
  wndWc.lpfnWndProc = (WNDPROC) WndProc;
  wndWc.cbClsExtra = 0;
  wndWc.cbWndExtra = 0;
  wndWc.hInstance = GetModuleHandle(NULL);
  wndWc.hIcon = NULL;
  wndWc.hCursor = LoadCursor(0, IDC_ARROW);
  wndWc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
  wndWc.lpszMenuName = NULL;
  wndWc.lpszClassName = L"w32skin";
  
  if (!RegisterClass(&wndWc)) return false;


  // get actual screen resolution
  int iSw = (WORD)GetSystemMetrics(SM_CXSCREEN);       // width
  int iSh = (WORD)GetSystemMetrics(SM_CYSCREEN);       // height

  RECT rc = { (iSw - 320)/2, (iSh - 240)/2, 320, 240 };

  hWnd = CreateWindow(L"w32skin", L"       w32skin",
                      WS_OVERLAPPEDWINDOW,
                      rc.left,rc.top,rc.right,rc.bottom,
                      NULL, NULL, GetModuleHandle(NULL), NULL);

  if (hWnd == NULL)
	{
		MessageBoxW(NULL, L"Error: create Window", NULL, MB_ICONERROR);
		return 2;
	}

  ShowWindow(hWnd, SW_SHOW);

  MSG msg;
  
  while (GetMessage(&msg,NULL,0,0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}
	
  DestroyWindow(hWnd);

  return 0;
}



// ------------------------------------------------------------------------
// Build a basic region and set it to the window.
// ------------------------------------------------------------------------
void RegionMe()
{

  HRGN hRegion1 = CreateEllipticRgn(20,-20,190,150);
  SetWindowRgn(hWnd, hRegion1, true);
  DeleteObject(hRegion1);
  bRegioned = true;
}



// ------------------------------------------------------------------------
// Remove the region from the window
// ------------------------------------------------------------------------
void UnRegionMe()
{
  SetWindowRgn(hWnd, NULL, true);
  bRegioned = false;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT uMessage, WPARAM wParam, LPARAM lParam)
{

  switch(uMessage)
  {

    case WM_KEYDOWN:
    {
      // ---------------------------------------------------------
      // pressing ESC will finish the app.
      // ---------------------------------------------------------
      switch (wParam)
      {
        case VK_ESCAPE:
          PostQuitMessage(0);
          break;

        case VK_SPACE:
          if (!bRegioned)
            RegionMe();
          else
            UnRegionMe();
      }
      break;
    }

    case WM_PAINT:
    {
      // -------------------------------------------------
      // tell user to press SPACE to toggle region.
      // -------------------------------------------------

      PAINTSTRUCT ps;
      BeginPaint(hWnd,&ps);

      TextOut(ps.hdc, 115,90, L"Press SPACE", 11);

      EndPaint(hWnd,&ps);

      break;
    }

    case WM_DESTROY:
    {
      PostQuitMessage(0);
      break;
    }


  }

  return DefWindowProc(hWnd,uMessage,wParam,lParam);
}