Microsoft DirectX 9.0


The IsDefaultSourceRect method determines if the renderer is using the default source rectangle (pure virtual).


virtual HRESULT IsDefaultSourceRect(void) PURE;

Return Value

Returns S_OK if the renderer is using the default source; otherwise, returns S_FALSE.


This member function must be implemented in the derived class. It is called by the CBaseControlVideo::IsUsingDefaultSource member function.

The following example demonstrates an implementation of this function in a derived class.

// Return S_OK if using the default source; otherwise, S_FALSE.
HRESULT CVideoText::IsDefaultSourceRect()
    RECT SourceRect;

    VIDEOINFO *pVideoInfo = (VIDEOINFO *) m_pRenderer->m_mtIn.Format();
    BITMAPINFOHEADER *pHeader = HEADER(pVideoInfo);

    // Check the coordinates that match the video dimensions.

    if (SourceRect.left != 0 || != 0 ||
            SourceRect.right != pHeader->biWidth ||
                SourceRect.bottom != pHeader->biHeight) {
                    return S_FALSE;
    return S_OK;

In this example, CVideoText is a class derived from CBaseControlVideo, m_pRenderer holds an object of a class derived from CBaseVideoRenderer, and the m_DrawImage data member, defined in the derived class, holds a CDrawImage object. The m_mtIn data member, also defined in the derived class, holds a CMediaType object with the media type of the input pin.

See Also