DWriteTextRenderer Class Reference

Internal helper class for rendering text using DirectWrite and Direct2D. More...

#include <DWriteTextRenderer.h>

Public Member Functions
bool	drawText (std::string_view text, const FontDefinition &textDefinition, unsigned int align, bool &premultipliedAlpha, SIZE &extent, tlx::byte_buffer &outData)
	Render UTF-8 text into a WIC bitmap and return its pixel data.

Detailed Description

Internal helper class for rendering text using DirectWrite and Direct2D.

Member Function Documentation

drawText()

bool drawText	(	std::string_view	text,
		const FontDefinition &	textDefinition,
		unsigned int	align,
		bool &	premultipliedAlpha,
		SIZE &	extent,
		tlx::byte_buffer &	outData )

Render UTF-8 text into a WIC bitmap and return its pixel data.

This function uses DirectWrite/Direct2D to draw text into a WIC bitmap, applying font settings, alignment, wrapping, overflow rules, stroke and shadow effects. The rendered bitmap is then copied into the provided output buffer in 32-bit BGRA format with premultiplied alpha.

Parameters

text	UTF-8 encoded text string to render. Line breaks (' ') are supported.
textDefinition	FontDefinition structure specifying font family, size, color, stroke and shadow options, wrapping and overflow behavior.
align	Alignment flags (compatible with BitmapDC): Horizontal: bits 0–3 (1 = left, 2 = right, 3 = center). Vertical: bits 4–7 (1 = top, 2 = bottom, 3 = middle).
premultipliedAlpha	Output flag indicating whether the pixel data uses premultiplied alpha.
extent	Input: maximum width/height constraints. Output: actual rendered text size in pixels.
outData	Output buffer containing raw pixel data (BGRA, premultiplied alpha).

Note

'&' characters are escaped by doubling ('&&') to avoid mnemonic interpretation.

If overflow == 2, the font size may be reduced iteratively until the text fits.

When stroke is enabled, glyph outlines are converted into geometry and drawn with both stroke and fill.

Alignment is handled by DirectWrite layout; origin is adjusted only for bounding box placement.

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The documentation for this class was generated from the following file:

• DWriteTextRenderer.h