ID2D1BitmapRenderTarget::GetBitmap method (d2d1.h)

Article
10/13/2021

Retrieves the bitmap for this render target. The returned bitmap can be used for drawing operations.

Syntax

HRESULT GetBitmap(
  [out] ID2D1Bitmap **bitmap
);

Parameters

[out] bitmap

Type: ID2D1Bitmap**

When this method returns, contains the address of a pointer to the bitmap for this render target. This bitmap can be used for drawing operations.

Return value

Type: HRESULT

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

Remarks

The DPI for the ID2D1Bitmap obtained from GetBitmap will be the DPI of the ID2D1BitmapRenderTarget when the render target was created. Changing the DPI of the ID2D1BitmapRenderTarget by calling SetDpi doesn't affect the DPI of the bitmap, even if SetDpi is called before GetBitmap. Using SetDpi to change the DPI of the ID2D1BitmapRenderTarget does affect how contents are rendered into the bitmap: it just doesn't affect the DPI of the bitmap retrieved by GetBitmap.

Examples

The following example uses the CreateCompatibleRenderTarget method to create an ID2D1BitmapRenderTarget and uses it to draw a grid pattern. The grid pattern is used as the source of an ID2D1BitmapBrush.

HRESULT DemoApp::CreateGridPatternBrush(
    ID2D1RenderTarget *pRenderTarget,
    ID2D1BitmapBrush **ppBitmapBrush
    )
{
    // Create a compatible render target.
    ID2D1BitmapRenderTarget *pCompatibleRenderTarget = NULL;
    HRESULT hr = pRenderTarget->CreateCompatibleRenderTarget(
        D2D1::SizeF(10.0f, 10.0f),
        &pCompatibleRenderTarget
        );
    if (SUCCEEDED(hr))
    {
        // Draw a pattern.
        ID2D1SolidColorBrush *pGridBrush = NULL;
        hr = pCompatibleRenderTarget->CreateSolidColorBrush(
            D2D1::ColorF(D2D1::ColorF(0.93f, 0.94f, 0.96f, 1.0f)),
            &pGridBrush
            );
        if (SUCCEEDED(hr))
        {
            pCompatibleRenderTarget->BeginDraw();
            pCompatibleRenderTarget->FillRectangle(D2D1::RectF(0.0f, 0.0f, 10.0f, 1.0f), pGridBrush);
            pCompatibleRenderTarget->FillRectangle(D2D1::RectF(0.0f, 0.1f, 1.0f, 10.0f), pGridBrush);
            pCompatibleRenderTarget->EndDraw();

            // Retrieve the bitmap from the render target.
            ID2D1Bitmap *pGridBitmap = NULL;
            hr = pCompatibleRenderTarget->GetBitmap(&pGridBitmap);
            if (SUCCEEDED(hr))
            {
                // Choose the tiling mode for the bitmap brush.
                D2D1_BITMAP_BRUSH_PROPERTIES brushProperties =
                    D2D1::BitmapBrushProperties(D2D1_EXTEND_MODE_WRAP, D2D1_EXTEND_MODE_WRAP);

                // Create the bitmap brush.
                hr = m_pRenderTarget->CreateBitmapBrush(pGridBitmap, brushProperties, ppBitmapBrush);

                pGridBitmap->Release();
            }

            pGridBrush->Release();
        }

        pCompatibleRenderTarget->Release();
    }

    return hr;
}

The following code example uses the brush to paint a pattern.

// Paint a grid background.
m_pRenderTarget->FillRectangle(
    D2D1::RectF(0.0f, 0.0f, renderTargetSize.width, renderTargetSize.height),
    m_pGridPatternBitmapBrush
    );

Code has been omitted from this example.

Requirements

Requirement	Value
Minimum supported client	Windows 7, Windows Vista with SP2 and Platform Update for Windows Vista [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2008 R2, Windows Server 2008 with SP2 and Platform Update for Windows Server 2008 [desktop apps \| UWP apps]
Target Platform	Windows
Header	d2d1.h
Library	D2d1.lib
DLL	D2d1.dll

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