Font cache for fonts that are based on a TrueType font. More...

#include <truetypefontcache.h>

Inheritance diagram for TrueTypeFontCache:

Data Structures
struct	GlyphEntry
	Container for information about a glyph. More...

Public Member Functions
	TrueTypeFontCache (FontSize fs, int pixels)
	Create a new TrueTypeFontCache. More...

virtual	~TrueTypeFontCache ()
	Free everything that was allocated for this font cache.

int	GetFontSize () const override
	Get the nominal font size of the font. More...

void	SetUnicodeGlyph (char32_t key, SpriteID sprite) override
	Map a SpriteID to the key. More...

void	InitializeUnicodeGlyphMap () override
	Initialize the glyph map.

const Sprite *	GetGlyph (GlyphID key) override
	Get the glyph (sprite) of the given key. More...

const void *	GetFontTable (uint32_t tag, size_t &length) override
	Read a font table from the font. More...

void	ClearFontCache () override
	Reset cached glyphs.

uint	GetGlyphWidth (GlyphID key) override
	Get the width of the glyph with the given key. More...

bool	GetDrawGlyphShadow () override
	Do we need to draw a glyph shadow? More...

bool	IsBuiltInFont () override
	Is this a built-in sprite font?

Public Member Functions inherited from FontCache
	FontCache (FontSize fs)
	Create a new font cache. More...

virtual	~FontCache ()
	Clean everything up.

FontSize	GetSize () const
	Get the FontSize of the font. More...

int	GetHeight () const
	Get the height of the font. More...

int	GetAscender () const
	Get the ascender value of the font. More...

int	GetDescender () const
	Get the descender value of the font. More...

int	GetUnitsPerEM () const
	Get the units per EM value of the font. More...

virtual GlyphID	MapCharToGlyph (char32_t key, bool fallback=true)=0
	Map a character into a glyph. More...

virtual const void *	GetOSHandle ()
	Get the native OS font handle, if there is one. More...

virtual std::string	GetFontName ()=0
	Get the name of this font. More...

bool	HasParent ()
	Check whether the font cache has a parent.

Protected Types
using	FontTable = std::map< uint32_t, std::pair< size_t, const void * > >
	Table with font table cache.

Protected Member Functions
GlyphEntry *	GetGlyphPtr (GlyphID key)

void	SetGlyphPtr (GlyphID key, const GlyphEntry *glyph, bool duplicate=false)

virtual const void *	InternalGetFontTable (uint32_t tag, size_t &length)=0

virtual const Sprite *	InternalGetGlyph (GlyphID key, bool aa)=0

Protected Attributes
int	req_size
	Requested font size.

int	used_size
	Used font size.

FontTable	font_tables
	Cached font tables.

GlyphEntry **	glyph_to_sprite
	The glyph cache. More...

Protected Attributes inherited from FontCache
FontCache *	parent
	The parent of this font cache.

const FontSize	fs
	The size of the font.

int	height
	The height of the font.

int	ascender
	The ascender value of the font.

int	descender
	The descender value of the font.

int	units_per_em
	The units per EM value of the font.

Static Protected Attributes
static constexpr int	MAX_GLYPH_DIM = 256
	Maximum glyph dimensions.

static constexpr uint	MAX_FONT_MIN_REC_SIZE = 20u
	Upper limit for the recommended font size in case a font file contains nonsensical values.

Static Protected Attributes inherited from FontCache
static FontCache *	caches [FS_END]
	All the font caches.

Additional Inherited Members
Static Public Member Functions inherited from FontCache
static void	InitializeFontCaches ()

static int	GetDefaultFontHeight (FontSize fs)

static FontCache *	Get (FontSize fs)
	Get the font cache of a given font size. More...

static std::string	GetName (FontSize fs)
	Get the font name of a given font size. More...

Detailed Description

Font cache for fonts that are based on a TrueType font.

Definition at line 22 of file truetypefontcache.h.

Constructor & Destructor Documentation

◆ TrueTypeFontCache()

TrueTypeFontCache::TrueTypeFontCache	(	FontSize	fs,
		int	pixels
	)

Create a new TrueTypeFontCache.

Parameters

fs	The font size that is going to be cached.
pixels	The number of pixels this font should be high.

Definition at line 25 of file truetypefontcache.cpp.

Member Function Documentation

◆ GetDrawGlyphShadow()

bool TrueTypeFontCache::GetDrawGlyphShadow ( )

overridevirtual

Do we need to draw a glyph shadow?

Returns: True if it has to be done, otherwise false.

Implements FontCache.

Definition at line 92 of file truetypefontcache.cpp.

References FontCache::fs, and FS_NORMAL.

◆ GetFontSize()

int TrueTypeFontCache::GetFontSize ( ) const

inlineoverridevirtual

Get the nominal font size of the font.

Returns: The nominal font size.

Reimplemented from FontCache.

Definition at line 64 of file truetypefontcache.h.

References used_size.

◆ GetFontTable()

const void * TrueTypeFontCache::GetFontTable	(	uint32_t	tag,
		size_t &	length
	)

overridevirtual

Read a font table from the font.

Parameters

tag	The of the table to load.
length	The length of the read data.

Returns: The loaded table data.

Implements FontCache.

Definition at line 168 of file truetypefontcache.cpp.

References font_tables.

◆ GetGlyph()

const Sprite * TrueTypeFontCache::GetGlyph ( GlyphID key )

overridevirtual

Get the glyph (sprite) of the given key.

Parameters

key	The key to look up.

Returns: The sprite.

Implements FontCache.

Definition at line 110 of file truetypefontcache.cpp.

◆ GetGlyphWidth()

uint TrueTypeFontCache::GetGlyphWidth ( GlyphID key )

overridevirtual

Get the width of the glyph with the given key.

Parameters

key	The key to look up.

Returns: The width.

Implements FontCache.

Definition at line 97 of file truetypefontcache.cpp.

◆ SetUnicodeGlyph()

void TrueTypeFontCache::SetUnicodeGlyph	(	char32_t	key,
		SpriteID	sprite
	)

inlineoverridevirtual

Map a SpriteID to the key.

Parameters

key	The key to map to.
sprite	The sprite that is being mapped.

Implements FontCache.

Definition at line 65 of file truetypefontcache.h.

References FontCache::parent, and FontCache::SetUnicodeGlyph().

Field Documentation

◆ glyph_to_sprite

GlyphEntry** TrueTypeFontCache::glyph_to_sprite

protected

The glyph cache.

This is structured to reduce memory consumption. 1) There is a 'segment' table for each font size. 2) Each segment table is a discrete block of characters. 3) Each block contains 256 (aligned) characters sequential characters.

The cache is accessed in the following way: For character 0x0041 ('A'): glyph_to_sprite[0x00][0x41] For character 0x20AC (Euro): glyph_to_sprite[0x20][0xAC]

Currently only 256 segments are allocated, "limiting" us to 65536 characters. This can be simply changed in the two functions Get & SetGlyphPtr.

Definition at line 53 of file truetypefontcache.h.

Referenced by ClearFontCache().

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

src/fontcache/truetypefontcache.h
src/fontcache/truetypefontcache.cpp

Data Structures

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Static Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ TrueTypeFontCache()

Member Function Documentation

◆ GetDrawGlyphShadow()

◆ GetFontSize()

◆ GetFontTable()

◆ GetGlyph()

◆ GetGlyphWidth()

◆ SetUnicodeGlyph()

Field Documentation

◆ glyph_to_sprite