diff --git a/freeglut/freeglut/src/mswin/fg_main_mswin.c b/freeglut/freeglut/src/mswin/fg_main_mswin.c index 4bd7039..c9c0ccf 100644 --- a/freeglut/freeglut/src/mswin/fg_main_mswin.c +++ b/freeglut/freeglut/src/mswin/fg_main_mswin.c @@ -648,14 +648,21 @@ LRESULT CALLBACK fgPlatformWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam, LPAR case WM_PAINT: { - PAINTSTRUCT ps; - /* Turn on the visibility in case it was turned off somehow */ - window->State.Visible = GL_TRUE; + RECT rect; - InvalidateRect( hWnd, NULL, GL_FALSE ); /* Make sure whole window is repainted. Bit of a hack, but a safe one from what google turns up... */ - BeginPaint( hWnd, &ps ); - fghRedrawWindow( window ); - EndPaint( hWnd, &ps ); + if (GetUpdateRect(hWnd,&rect,FALSE)) + { + /* As per docs, upon receiving WM_PAINT, first check if the update region is not empty before you call BeginPaint */ + PAINTSTRUCT ps; + + /* Turn on the visibility in case it was turned off somehow */ + window->State.Visible = GL_TRUE; + + InvalidateRect( hWnd, NULL, GL_FALSE ); + BeginPaint( hWnd, &ps ); + fghRedrawWindow( window ); + EndPaint( hWnd, &ps ); + } } break;