tt::FontBook Class Reference

#include <TTauri/Text/FontBook.hpp>

Public Member Functions
	FontBook (std::vector< URL > const &font_directories)
FontID	register_font (URL url, bool post_process=true)
	Register a font.
void	post_process () noexcept
	Post process FontBook Should be called after a set of register_font() calls This calculates font fallbacks.
FontFamilyID	find_family (std::string_view family_name) const noexcept
	Find font family id.
FontFamilyID	register_family (std::string_view family_name) noexcept
	Register font family id.
FontID	find_font (FontFamilyID family_id, FontVariant variant) const noexcept
	Find a font closest to the variant.
FontID	find_font (FontFamilyID family_id, FontWeight weight, bool italic) const noexcept
	Find a font closest to the variant.
FontID	find_font (std::string_view family_name, FontWeight weight, bool italic) const noexcept
	Find a font closest to the variant.
Font const &	get_font (FontID font_id) const noexcept
FontGlyphIDs	find_glyph (FontID font_id, Grapheme grapheme) const noexcept
	Find a glyph using the given code-point.

Detailed Description

FontBook keeps track of multiple fonts.

The FontBook is instantiated during Application startup and is available through Foundation_globals->font_book.

Member Function Documentation

find_family()

FontFamilyID tt::FontBook::find_family ( std::string_view family_name ) const

noexcept

Find font family id.

This function will always return a valid FontFamilyID by walking the fallback-chain.

find_font() [1/3]

FontID tt::FontBook::find_font ( FontFamilyID family_id, FontVariant variant ) const

noexcept

Find a font closest to the variant.

This function will always return a valid FontID.

Parameters

family_id	a valid family id.
variant	The variant of the font to select.

Returns

a valid font id.

find_font() [2/3]

FontID tt::FontBook::find_font ( FontFamilyID family_id, FontWeight weight, bool italic ) const

noexcept

Find a font closest to the variant.

This function will always return a valid FontID.

Parameters

family_id	a valid family id.
weight	The weight of the font to select.
italic	If the font to select should be italic or not.

Returns

a valid font id.

find_font() [3/3]

FontID tt::FontBook::find_font ( std::string_view family_name, FontWeight weight, bool italic ) const

noexcept

Find a font closest to the variant.

This function will always return a valid FontID.

Parameters

family_id	a valid family id.
weight	The weight of the font to select.
italic	If the font to select should be italic or not.

Returns

a valid font id.

find_glyph()

FontGlyphIDs tt::FontBook::find_glyph ( FontID font_id, Grapheme grapheme ) const

noexcept

Find a glyph using the given code-point.

This function will find a glyph matching the grapheme in the selected font, or find the glyph in the fallback font.

Parameters

font_id	The font to use to find the grapheme in.
grapheme	The Unicode grapheme to find in the font.

Returns

A list of glyphs which matched the grapheme.

post_process()

void tt::FontBook::post_process ( )

noexcept

Post process FontBook Should be called after a set of register_font() calls This calculates font fallbacks.

register_family()

FontFamilyID tt::FontBook::register_family ( std::string_view family_name )

noexcept

Register font family id.

If the family already exists the existing family_id is returned.

register_font()

FontID tt::FontBook::register_font	(	URL	url,
		bool	post_process = true )

Register a font.

Duplicate registrations will be ignored.

When a font file is registered the file will be temporarily opened to read and cache a set of properties:

• The English Font Family from the 'name' table.
• The weight, width, slant & design-size from the 'fdsc' table.
• The character map 'cmap' table.

Parameters

url	Location of font.
post_process	Calculate font fallback

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

• hikogui/src/TTauri/Text/FontBook.hpp