cangine::TextRenderer Class Reference

Singleton that loads fonts and renders text via FreeType. More...

#include <text_renderer.hpp>

Collaboration diagram for cangine::TextRenderer:

Public Member Functions
void	clearGlyphCache (Font *font)
	Clears the cached glyphs for a font.
Font *	loadFont (std::string path, int height=40)
	Loads a font from disk (or returns the cached one).
void	setFontHeight (Font *font, int heightIn)
	Changes a font's pixel height and clears its glyph cache.
bool	loadGlyph (Font *font, uint32_t cp)
	Rasterizes and caches a single glyph.
void	renderText (Font *font, const std::string &text, Vector3 pos, float scale, const Color &color)
	Draws a text string at a position.
Vector2	measureText (Font *font, const std::string &text, float scale)
	Measures the rendered size of a text string.
	TextRenderer ()
	Constructs the renderer and initializes FreeType.
	~TextRenderer ()
	Releases FreeType resources.

Static Public Member Functions
static TextRenderer *	getInstance ()
	Returns the singleton instance.

Public Attributes
bool	valid
	Whether the renderer initialized successfully.

Private Member Functions
bool	init_freetype ()
	Initializes the FreeType library.

Private Attributes
FT_Library	ft
	FreeType library handle.
std::unordered_map< std::string, std::unique_ptr< Font > >	fonts
	Loaded fonts keyed by path.

Static Private Attributes
static TextRenderer *	instance = nullptr
	Singleton instance.

Detailed Description

Singleton that loads fonts and renders text via FreeType.

Rasterizes glyphs on demand, caches them per Font, and draws text as textured quads.

Constructor & Destructor Documentation

TextRenderer()

cangine::TextRenderer::TextRenderer

(

)

Constructs the renderer and initializes FreeType.

~TextRenderer()

cangine::TextRenderer::~TextRenderer

(

)

Releases FreeType resources.

Member Function Documentation

clearGlyphCache()

void cangine::TextRenderer::clearGlyphCache

(

Font *

font

)

Clears the cached glyphs for a font.

Parameters

font	Font whose glyph cache should be emptied.

getInstance()

TextRenderer * cangine::TextRenderer::getInstance ( )

static

Returns the singleton instance.

Returns

Pointer to the TextRenderer instance.

init_freetype()

bool cangine::TextRenderer::init_freetype ( )

private

Initializes the FreeType library.

Returns

true on success, false on failure.

loadFont()

Font * cangine::TextRenderer::loadFont	(	std::string	path,
		int	height = 40
	)

Loads a font from disk (or returns the cached one).

Parameters

path	Path to the font file.
height	Pixel height to render the font at.

Returns

Pointer to the loaded font, or nullptr on failure.

loadGlyph()

bool cangine::TextRenderer::loadGlyph	(	Font *	font,
		uint32_t	cp
	)

Rasterizes and caches a single glyph.

Parameters

font	Font to load the glyph for.
cp	Unicode codepoint of the glyph.

Returns

true if the glyph was loaded successfully.

measureText()

Vector2 cangine::TextRenderer::measureText	(	Font *	font,
		const std::string &	text,
		float	scale = 1.0f
	)

Measures the rendered size of a text string.

Parameters

font	Font that would render the text.
text	UTF-8 text to measure.
scale	Scale factor applied to the glyphs.

Returns

The width and height the text would occupy.

renderText()

void cangine::TextRenderer::renderText	(	Font *	font,
		const std::string &	text,
		Vector3	pos,
		float	scale,
		const Color &	color
	)

Draws a text string at a position.

Parameters

font	Font to render with.
text	UTF-8 text to draw.
pos	Baseline position (z is the layer).
scale	Scale factor applied to the glyphs.
color	Text color.

setFontHeight()

void cangine::TextRenderer::setFontHeight	(	Font *	font,
		int	heightIn
	)

Changes a font's pixel height and clears its glyph cache.

Parameters

font	Font to modify.
heightIn	New pixel height.

Member Data Documentation

fonts

std::unordered_map<std::string, std::unique_ptr<Font> > cangine::TextRenderer::fonts

private

Loaded fonts keyed by path.

ft

FT_Library cangine::TextRenderer::ft

private

FreeType library handle.

instance

TextRenderer * cangine::TextRenderer::instance = nullptr

staticprivate

Singleton instance.

valid

bool cangine::TextRenderer::valid

Whether the renderer initialized successfully.

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

• cangine/src/cangine/render/renderer/text_renderer.hpp
• cangine/src/cangine/render/renderer/text_renderer.cpp