ID2D1Factory::CreateTransformedGeometry method

發行項
12/01/2017

Transforms the specified geometry and stores the result as an ID2D1TransformedGeometry object.

Syntax

virtual HRESULT CreateTransformedGeometry(
  [in]                 ID2D1Geometry            *sourceGeometry,
  [in, optional] const D2D1_MATRIX_3X2_F        *transform,
  [out]                ID2D1TransformedGeometry **transformedGeometry
) = 0;

Parameters

sourceGeometry [in]
Type: ID2D1Geometry*

The geometry to transform.
transform [in, optional]
Type: const D2D1_MATRIX_3X2_F*

The transformation to apply.
transformedGeometry [out]
Type: ID2D1TransformedGeometry**

When this method returns, contains the address of the pointer to the new transformed geometry object. The transformed geometry stores the result of transforming sourceGeometry by transform.

Return value

Type: HRESULT

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

Remarks

Like other resources, a transformed geometry inherits the resource space and threading policy of the factory that created it. This object is immutable.

When stroking a transformed geometry with the DrawGeometry method, the stroke width is not affected by the transform applied to the geometry. The stroke width is only affected by the world transform.

Examples

The following example creates an ID2D1RectangleGeometry, then draws it without transforming it. It produces the output shown in the following illustration.

Illustration of a rectangle

hr = m_pD2DFactory->CreateRectangleGeometry(
    D2D1::RectF(150.f, 150.f, 200.f, 200.f),
    &m_pRectangleGeometry
    );

The next example uses the render target to scale the geometry by a factor of 3, then draws it. The following illustration shows the result of drawing the rectangle without the transform and with the transform; notices that the stroke is thicker after the transform, even though the stroke thickness is 1.

Illustration of a smaller rectangle inside a larger rectangle with a thicker stroke

// Transform the render target, then draw the rectangle geometry again.
m_pRenderTarget->SetTransform(
    D2D1::Matrix3x2F::Scale(
        D2D1::SizeF(3.f, 3.f),
        D2D1::Point2F(175.f, 175.f))
    );

m_pRenderTarget->DrawGeometry(m_pRectangleGeometry, m_pBlackBrush, 1);

The next example uses the CreateTransformedGeometry method to scale the geometry by a factor of 3, then draws it. It produces the output shown in the following illustration. Notice that, although the rectangle is larger, its stroke hasn't increased.

Illustration of a smaller rectangle inside a larger rectangle with the same stroke

 // Create a geometry that is a scaled version
 // of m_pRectangleGeometry.
 // The new geometry is scaled by a factory of 3
 // from the center of the geometry, (35, 35).

 hr = m_pD2DFactory->CreateTransformedGeometry(
     m_pRectangleGeometry,
     D2D1::Matrix3x2F::Scale(
         D2D1::SizeF(3.f, 3.f),
         D2D1::Point2F(175.f, 175.f)),
     &m_pTransformedGeometry
     );

// Replace the previous render target transform.
m_pRenderTarget->SetTransform(D2D1::Matrix3x2F::Identity());

// Draw the transformed geometry.
m_pRenderTarget->DrawGeometry(m_pTransformedGeometry, m_pBlackBrush, 1);

Requirements

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]
Minimum supported phone	Windows Phone 8.1 [Windows Phone Silverlight 8.1 and Windows Runtime apps]
Header	D2d1.h
Library	D2d1.lib
DLL	D2d1.dll

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