flocking/Mirror.cpp
void
OnPaint(HWND hwnd) {
  PAINTSTRUCT ps;
  BeginPaint(hwnd, &ps);
  PaintContent(hwnd, &ps);
  EndPaint(hwnd, &ps);
}
/*
 *  OnPaint
 *      Paint the content as part of the paint cycle.
 */
OnPaint
Paint the content as part of the paint cycle.
OnPaint Paint the content as part of the paint cycle .
void
OnPaint(HWND hwnd) {
  PAINTSTRUCT ps;
  BeginPaint(hwnd, &ps);
  PaintContent(hwnd, &ps);
  EndPaint(hwnd, &ps);
}
void OnPaint ( HWND hwnd ) { PAINTSTRUCT ps ; BeginPaint ( hwnd , & ps ) ; PaintContent ( hwnd , & ps ) ; EndPaint ( hwnd , & ps ) ; }
OnPaint
      Paint the content as part of the paint cycle.
OnPaint Paint the content as part of the paint cycle .