ID2D1PathGeometry::Open method (d2d1.h)

Retrieves the geometry sink that is used to populate the path geometry with figures and segments.

Syntax

HRESULT Open(
  [out] ID2D1GeometrySink **geometrySink
);

Parameters

[out] geometrySink

Type: ID2D1GeometrySink**

When this method returns, geometrySink contains the address of a pointer to the geometry sink that is used to populate the path geometry with figures and segments. This parameter is passed uninitialized.

Return value

Type: HRESULT

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

Because path geometries are immutable and can only be populated once, it is an error to call Open on a path geometry more than once.

Note that the fill mode defaults to D2D1_FILL_MODE_ALTERNATE. To set the fill mode, call SetFillMode before the first call to BeginFigure. Failure to do so will put the geometry sink in an error state.

Examples

The following example creates an ID2D1PathGeometry, retrieves a sink, and uses the sink to define an hourglass shape. For the complete example, see How to Draw and Fill a Complex Shape.

ID2D1GeometrySink *pSink = NULL;

// Create a path geometry.
if (SUCCEEDED(hr))
{
    hr = m_pD2DFactory->CreatePathGeometry(&m_pPathGeometry);

    if (SUCCEEDED(hr))
    {
        // Write to the path geometry using the geometry sink.
        hr = m_pPathGeometry->Open(&pSink);

        if (SUCCEEDED(hr))
        {
            pSink->BeginFigure(
                D2D1::Point2F(0, 0),
                D2D1_FIGURE_BEGIN_FILLED
                );

            pSink->AddLine(D2D1::Point2F(200, 0));

            pSink->AddBezier(
                D2D1::BezierSegment(
                    D2D1::Point2F(150, 50),
                    D2D1::Point2F(150, 150),
                    D2D1::Point2F(200, 200))
                );

            pSink->AddLine(D2D1::Point2F(0, 200));

            pSink->AddBezier(
                D2D1::BezierSegment(
                    D2D1::Point2F(50, 150),
                    D2D1::Point2F(50, 50),
                    D2D1::Point2F(0, 0))
                );

            pSink->EndFigure(D2D1_FIGURE_END_CLOSED);

            hr = pSink->Close();
        }
        SafeRelease(&pSink);
    }
}

Requirements

See also

ID2D1PathGeometry