IDWriteGlyphRunAnalysis::CreateAlphaTexture method

Creates an alpha texture of the specified type for glyphs within a specified bounding rectangle.

Syntax

virtual HRESULT CreateAlphaTexture(
              DWRITE_TEXTURE_TYPE  textureType,
  [in]  const RECT                * textureBounds,
  [out]       BYTE                * alphaValues,
              UINT32               bufferSize
) = 0;

Parameters

textureType

Type: DWRITE_TEXTURE_TYPE

A value that specifies the type of texture requested. This can be DWRITE_TEXTURE_BILEVEL_1x1 or DWRITE_TEXTURE_CLEARTYPE_3x1. If a bi-level texture is requested, the texture contains only bi-level glyphs. Otherwise, the texture contains only antialiased glyphs.

textureBounds [in]

Type: const RECT*

The bounding rectangle of the texture, which can be different than the bounding rectangle returned by GetAlphaTextureBounds.

alphaValues [out]

Type: BYTE*

When this method returns, contains the array of alpha values from the texture. The buffer allocated for this array must be at least the size of bufferSize.

bufferSize

Type: UINT32

The size of the alphaValues array, in bytes. The minimum size depends on the dimensions of the rectangle and the type of texture requested.

Return value

Type: HRESULT

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

Requirements

See also

IDWriteGlyphRunAnalysis