/* mingwscr.c */

#include <windows.h>
#include <tchar.h>
#include <scrnsave.h>
#include <time.h>
#include <stdlib.h>

#define ID_TIMER 101

void DrawScreenSaver(HWND hWnd, UINT msg,
                     WPARAM wParam, LPARAM lParam)
{
  HDC hdc;
  RECT rc;
  HPEN hPen;
  int i, x, y, l, r, g, b;

  /* Draw circles at random sizes and locations */
  hdc = GetDC(hWnd);
  GetClientRect(hWnd, &rc);

  x = rand() % rc.right;
  y = rand() % rc.bottom;
  l = rand() % rc.right / 6;
  r = rand() % 256;
  g = rand() % 256;
  b = rand() % 256;

  /* set large pen size */
  hPen = CreatePen(PS_SOLID, l, RGB(r, g, b));
  SelectObject(hdc, hPen);

  /* draw point. pen size is large */
  MoveToEx(hdc, x, y, NULL);
  LineTo(hdc, x, y);

  ReleaseDC(hWnd, hdc);
}

/* screensaver main processing */
LRESULT WINAPI ScreenSaverProc(HWND hWnd, UINT msg,
                               WPARAM wParam, LPARAM lParam)
{
  switch (msg)
  {
  case WM_CREATE:
    /* initialize */
    SetTimer(hWnd, ID_TIMER, 33, NULL); /* create timer */
    srand((unsigned)time(NULL));
    break;
  case WM_TIMER:
    /* main loop */
    DrawScreenSaver(hWnd, msg, wParam, lParam);
    break;
  case WM_DESTROY:
    KillTimer(hWnd, ID_TIMER); /* kill timer */
    PostQuitMessage(0);
    break;
  default:
    break;
  }
  return DefScreenSaverProc(hWnd, msg, wParam, lParam);
}

/* Processing of dialog boxes for configuration */
BOOL WINAPI ScreenSaverConfigureDialog(HWND hDlg, UINT msg,
                                       WPARAM wParam, LPARAM lParam)
{
  switch (msg)
  {
  case WM_INITDIALOG:
    MessageBox(
        hDlg,
        _T("This screen saver has no configuration options."),
        _T("Sample Screensaver by using MinGW"),
        MB_OK | MB_ICONWARNING);
    EndDialog(hDlg, IDOK);
    return TRUE;
  case WM_COMMAND:
    switch (LOWORD(wParam))
    {
    case IDOK:
      EndDialog(hDlg, IDOK);
      return TRUE;
    case IDCANCEL:
      EndDialog(hDlg, IDCANCEL);
      return TRUE;
    }
    return FALSE;
  }

  return FALSE;
}

/* Register non-standard window classes required by dialog boxes for configuration */
BOOL WINAPI RegisterDialogClasses(HANDLE hInst)
{
  return TRUE;
}