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ID2D1ImageSourceFromWic::TrimCache(constD2D1_RECT_U*) method (d2d1_3.h)

  • Article

This method trims the populated regions of the image source cache to just the specified rectangle.

Syntax

HRESULT TrimCache(
  [in, optional] const D2D1_RECT_U *rectangleToPreserve
);

Parameters

[in, optional] rectangleToPreserve

Type: const D2D1_RECT_U*

Specifies the region of the image, in pixels, which should be preserved in the image source cache. Regions which are outside of the rectangle are evicted from the cache. By default, this is an empty rectangle, meaning that the entire image is evicted from the cache.

Return value

Type: HRESULT

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

Remarks

The provided region must be constructed to include the scale at which the image source will be drawn at. These coordinates must be provided in local coordinates.
This means that they must be adjusted prior to calling the API according to the DPI and other relevant transforms, which can include the world transform and brush transforms.

This method will fail if on-demand caching was not requested when the image source was created.

As with ID2D1Device::ClearResources, the caller can need to subsequently issue a D3D flush before memory usage is reduced.

This operation is only supported when the image source has been initialized using the D2D1_IMAGE_SOURCE_LOADING_OPTIONS_CACHE_ON_DEMAND option.

Requirements

Requirement Value
Target Platform Windows
Header d2d1_3.h
Library D2d1_3.lib
DLL D2d1_3.dll

See also

ID2D1ImageSourceFromWic