Class TextRendererBase

Namespace

SharpDX.DirectWrite

Assembly

SharpDX.Direct2D1.dll

Default abstract implementation of TextRenderer. Need to implement a least a DrawXXX method to use it.

public abstract class TextRendererBase : CallbackBase, TextRenderer, PixelSnapping, IUnknown, ICallbackable, IDisposable

Inheritance

object

TextRendererBase

Implements

TextRenderer

PixelSnapping

IUnknown

ICallbackable

IDisposable

Constructors

TextRendererBase()

protected TextRendererBase()

Methods

DrawGlyphRun(object, float, float, MeasuringMode, GlyphRun, GlyphRunDescription, ComObject)

IDWriteTextLayout::Draw calls this function to instruct the client to render a run of glyphs.

public virtual Result DrawGlyphRun(object clientDrawingContext, float baselineOriginX, float baselineOriginY, MeasuringMode measuringMode, GlyphRun glyphRun, GlyphRunDescription glyphRunDescription, ComObject clientDrawingEffect)

Parameters

clientDrawingContext object

The application-defined drawing context passed to .

baselineOriginX float

The pixel location (X-coordinate) at the baseline origin of the glyph run.

baselineOriginY float

The pixel location (Y-coordinate) at the baseline origin of the glyph run.

measuringMode MeasuringMode

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

glyphRun GlyphRun

Pointer to the glyph run instance to render.

glyphRunDescription GlyphRunDescription

A pointer to the optional glyph run description instance which contains properties of the characters associated with this run.

clientDrawingEffect ComObject

Application-defined drawing effects for the glyphs to render. Usually this argument represents effects such as the foreground brush filling the interior of text.

Returns

Result

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

Remarks

The function calls this callback function with all the information about glyphs to render. The application implements this callback by mostly delegating the call to the underlying platform's graphics API such as {{Direct2D}} to draw glyphs on the drawing context. An application that uses GDI can implement this callback in terms of the method.

DrawInlineObject(object, float, float, InlineObject, bool, bool, ComObject)

IDWriteTextLayout::Draw calls this application callback when it needs to draw an inline object.

public virtual Result DrawInlineObject(object clientDrawingContext, float originX, float originY, InlineObject inlineObject, bool isSideways, bool isRightToLeft, ComObject clientDrawingEffect)

Parameters

clientDrawingContext object

The application-defined drawing context passed to IDWriteTextLayout::Draw.

originX float

X-coordinate at the top-left corner of the inline object.

originY float

Y-coordinate at the top-left corner of the inline object.

inlineObject InlineObject

The application-defined inline object set using IDWriteTextFormat::SetInlineObject.

isSideways bool

A Boolean flag that indicates whether the object's baseline runs alongside the baseline axis of the line.

isRightToLeft bool

A Boolean flag that indicates whether the object is in a right-to-left context, hinting that the drawing may want to mirror the normal image.

clientDrawingEffect ComObject

Application-defined drawing effects for the glyphs to render. Usually this argument represents effects such as the foreground brush filling the interior of a line.

Returns

Result

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

DrawStrikethrough(object, float, float, ref Strikethrough, ComObject)

IDWriteTextLayout::Draw calls this function to instruct the client to draw a strikethrough.

public virtual Result DrawStrikethrough(object clientDrawingContext, float baselineOriginX, float baselineOriginY, ref Strikethrough strikethrough, ComObject clientDrawingEffect)

Parameters

clientDrawingContext object

The application-defined drawing context passed to IDWriteTextLayout::Draw.

baselineOriginX float

The pixel location (X-coordinate) at the baseline origin of the run where strikethrough applies.

baselineOriginY float

The pixel location (Y-coordinate) at the baseline origin of the run where strikethrough applies.

strikethrough Strikethrough

Pointer to a structure containing strikethrough logical information.

clientDrawingEffect ComObject

Application-defined effect to apply to the strikethrough. Usually this argument represents effects such as the foreground brush filling the interior of a line.

Returns

Result

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

Remarks

A single strikethrough can be broken into multiple calls, depending on how the formatting changes attributes. Strikethrough is not averaged across font sizes/styles changes. To get an appropriate starting pixel position, add strikethrough::offset to the baseline. Like underlines, the x coordinate will always be passed as the left side, regardless of text directionality.

DrawUnderline(object, float, float, ref Underline, ComObject)

IDWriteTextLayout::Draw calls this function to instruct the client to draw an underline.

public virtual Result DrawUnderline(object clientDrawingContext, float baselineOriginX, float baselineOriginY, ref Underline underline, ComObject clientDrawingEffect)

Parameters

clientDrawingContext object

The application-defined drawing context passed to IDWriteTextLayout::Draw.

baselineOriginX float

The pixel location (X-coordinate) at the baseline origin of the run where underline applies.

baselineOriginY float

The pixel location (Y-coordinate) at the baseline origin of the run where underline applies.

underline Underline

Pointer to a structure containing underline logical information.

clientDrawingEffect ComObject

Application-defined effect to apply to the underline. Usually this argument represents effects such as the foreground brush filling the interior of a line.

Returns

Result

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

Remarks

A single underline can be broken into multiple calls, depending on how the formatting changes attributes. If font sizes/styles change within an underline, the thickness and offset will be averaged weighted according to characters. To get an appropriate starting pixel position, add underline::offset to the baseline. Otherwise there will be no spacing between the text. The x coordinate will always be passed as the left side, regardless of text directionality. This simplifies drawing and reduces the problem of round-off that could potentially cause gaps or a double stamped alpha blend. To avoid alpha overlap, round the end points to the nearest device pixel.

GetCurrentTransform(object)

Gets a transform that maps abstract coordinates to DIPs.

public virtual RawMatrix3x2 GetCurrentTransform(object clientDrawingContext)

Parameters

clientDrawingContext object

The drawing context passed to .

Returns

RawMatrix3x2

a structure which has transform information for pixel snapping.

GetPixelsPerDip(object)

Gets the number of physical pixels per DIP.

public virtual float GetPixelsPerDip(object clientDrawingContext)

Parameters

clientDrawingContext object

The drawing context passed to .

Returns

float

the number of physical pixels per DIP

Remarks

Because a DIP (device-independent pixel) is 1/96 inch, the pixelsPerDip value is the number of logical pixels per inch divided by 96.

IsPixelSnappingDisabled(object)

Determines whether pixel snapping is disabled. The recommended default is FALSE, unless doing animation that requires subpixel vertical placement.

public virtual bool IsPixelSnappingDisabled(object clientDrawingContext)

Parameters

clientDrawingContext object

The context passed to IDWriteTextLayout::Draw.

Returns

bool

Receives TRUE if pixel snapping is disabled or FALSE if it not.