IDWriteBitmapRenderTarget::DrawGlyphRun method

Draws a run of glyphs to a bitmap target at the specified position.

Syntax

virtual HRESULT DrawGlyphRun(
  FLOAT  baselineOriginX,
  FLOAT  baselineOriginY,
  DWRITE_MEASURING_MODE  measuringMode,
  [in]             const DWRITE_GLYPH_RUN * glyphRun,
  IDWriteRenderingParams * renderingParams,
  COLORREF  textColor,
  [out, optional]  RECT * blackBoxRect
) = 0;

Parameters

baselineOriginX

Type: FLOAT

The horizontal position of the baseline origin, in DIPs, relative to the upper-left corner of the DIB.

baselineOriginY

Type: FLOAT

The vertical position of the baseline origin, in DIPs, relative to the upper-left corner of the DIB.

measuringMode

Type: DWRITE_MEASURING_MODE

The measuring method for glyphs in the run, used with the other properties to determine the rendering mode.

glyphRun [in]

Type: const DWRITE_GLYPH_RUN*

The structure containing the properties of the glyph run.

renderingParams

Type: IDWriteRenderingParams*

The object that controls rendering behavior.

textColor

Type: COLORREF

The foreground color of the text.

blackBoxRect [out, optional]

Type: RECT*

The optional rectangle that receives the bounding box (in pixels not DIPs) of all the pixels affected by drawing the glyph run. The black box rectangle may extend beyond the dimensions of the bitmap.

Return value

Type: HRESULT

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

Remarks

You can use the IDWriteBitmapRenderTarget::DrawGlyphRun to render to a bitmap from a custom text renderer that you implement. The custom text renderer should call this method from within the IDWriteTextRenderer::DrawGlyphRun callback method as shown in the following code.

STDMETHODIMP GdiTextRenderer::DrawGlyphRun(
    __maybenull void* clientDrawingContext,
    FLOAT baselineOriginX,
    FLOAT baselineOriginY,
    DWRITE_MEASURING_MODE measuringMode,
    __in DWRITE_GLYPH_RUN const* glyphRun,
    __in DWRITE_GLYPH_RUN_DESCRIPTION const* glyphRunDescription,
    IUnknown* clientDrawingEffect
    )
{
    HRESULT hr = S_OK;

    // Pass on the drawing call to the render target to do the real work.
    RECT dirtyRect = {0};

    hr = pRenderTarget_->DrawGlyphRun(
        baselineOriginX,
        baselineOriginY,
        measuringMode,
        glyphRun,
        pRenderingParams_,
        RGB(0,200,255),
        &dirtyRect
        );
    

    return hr;
}

The baselineOriginX, baslineOriginY, measuringMethod, and glyphRun parameters are provided (as arguments) when the callback method is invoked. The renderingParams, textColor and blackBoxRect are not.

Default rendering params can be retrieved by using the IDWriteFactory::CreateMonitorRenderingParams method.

Requirements

See also

IDWriteBitmapRenderTarget

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Build date: 11/22/2012