PRB: Most Common Cause of SetPixelFormat() Failure

• Microsoft Win32 Application Programming Interface (API) included with:

      - Microsoft Windows NT versions 3.5 and 3.51
      - Microsoft Windows 95 version 4.0
  

SYMPTOMS

SetPixelFormat() will fail with incorrect class or window styles.

CAUSE

Win32-based applications that use Microsoft's implementation of OpenGL to render onto a window must include WS_CLIPCHILDREN and WS_CLIPSIBLINGS window styles for that window.

RESOLUTION

Include WS_CLIPCHILDREN and WS_CLIPSIBLINGS window styles when in a Win32- based application, you use Microsoft's implementation of OpenGL to render onto a window.

Additionally, the window class attribute should not include the CS_PARENTDC style. The two window styles can be added to the dwStyles parameter of CreateWindow() or CreateWindowEX() call. If MFC is used, override PreCreateWindow() to add the flags. For example:

    BOOL CMyView::PreCreateWindow(CREATESTRUCT& cs)
    {
        cs.style |= (WS_CLIPCHILDREN | WS_CLIPSIBLINGS);

        return CView::PreCreateWindow(cs);
    }

STATUS

This behavior is by design.