Data Structures
struct	range_t
	A range of codepoint (part of rdpq_font_t) More...

struct	sparse_range_t
	Sparse range table. More...

struct	glyph_t
	A glyph in the font (part of rdpq_font_t) More...

struct	glyph_krange_t
	For each glyph, range of kerning pairs in the kerning table. More...

struct	atlas_t
	A texture atlas (part of rdpq_font_t) More...

struct	kerning_t
	Kerning data for a pair of glyphs. More...

struct	style_t
	Data related to font styling. More...

struct	rdpq_font_t
	A font64 file containing a font. More...

Macros
#define	FONT_MAGIC "FNT"
	font64 file magic header

#define	FONT_MAGIC_LOADED "FNL"
	font64 loaded font buffer magic

#define	FONT_MAGIC_OWNED "FNO"
	font64 owned font buffer magic

#define	FONT_FLAG_TYPE_MASK 0x0000000F
	Mask for the font type.

Enumerations
enum	fonttype_t { FONT_TYPE_ALIASED = 0 , FONT_TYPE_MONO = 1 , FONT_TYPE_MONO_OUTLINE = 2 , FONT_TYPE_ALIASED_OUTLINE = 3 , FONT_TYPE_BITMAP = 4 }
	Type of the font. More...

Functions
int16_t	__rdpq_font_glyph (const rdpq_font_t *font, uint32_t codepoint)
	Look up a glyph in a font.

void	__rdpq_font_glyph_metrics (const rdpq_font_t fnt, int16_t index, float xadvance, int8_t xoff, int8_t xoff2, bool has_kerning, uint8_t atlas_id)
	Get glyph metrics for a font glyph.

float	__rdpq_font_kerning (const rdpq_font_t *font, int16_t glyph1, int16_t glyph2)
	Get kerning between two glyphs.

Detailed Description

Author: Giovanni Bajo giova.nosp@m.nnib.nosp@m.ajo@g.nosp@m.mail.nosp@m..com

Data Structure Documentation

◆ range_t

struct range_t

A range of codepoint (part of rdpq_font_t)

Data Fields
uint32_t	first_codepoint	First codepoint in the range.
uint32_t	num_codepoints	Number of codepoints in the range.
int32_t	first_glyph	Index of the first glyph in the range (-1 if range is sparse)

◆ sparse_range_t

struct sparse_range_t

Sparse range table.

This is a perfect hash table used to encode glyph indices for codepoints. It is used for all sparse ranges, that is ranges where only some codepoints are defined within the min/max of the range, to avoid wasting too much memory in the glyph table for empty entries.

This uses the CHD (compress hash displace) perfect hash table algorithm, that is very fast at runtime and has very little complexity. Since we handle small tables by today's standard, this algorithm is a good fit.

Data Fields
uint32_t	seed	Seed for the hashing algorithm.
uint32_t	r	Number of elements in the displacement table.
uint32_t	m	Number of elements in the values table.
uint16_t *	g	Displacement table.
int16_t *	values	Values table (actual glyph indices)

◆ glyph_t

struct glyph_t

A glyph in the font (part of rdpq_font_t)

Data Fields
uint8_t	xadvance	Number of pixels to advance the cursor after drawing the glyph.
int8_t	xoff	Offset of the x0 coordinate of the glyph from the cursor.
int8_t	yoff	Offset of the y0 coordinate of the glyph from the cursor.
int8_t	xoff2	Offset of the exclusive x1 coordinate of the glyph from the cursor.
int8_t	yoff2	Offset of the exclusive y1 coordinate of the glyph from the cursor.
uint8_t	s	S texture coordinate of the glyph in the atlas.
uint8_t	t	T texture coordinate of the glyph in the atlas.
uint8_t	natlas: 6	Index of atlas that contains this glyph.
uint8_t	ntile: 2	Tile to use to draw the glyph (for multi-layer atlases)

◆ glyph_krange_t

struct glyph_krange_t

For each glyph, range of kerning pairs in the kerning table.

Data Fields
uint16_t	kerning_lo	Index of the first kerning pair for this glyph.
uint16_t	kerning_hi	Index of the last kerning pair for this glyph.

◆ atlas_t

struct atlas_t

A texture atlas (part of rdpq_font_t)

Data Fields
sprite_t *	sprite	Texture sprite.
uint32_t	size	Size of the sprite in bytes.
rspq_block_t *	up	RSPQ block that uploads the sprite.

◆ kerning_t

struct kerning_t

Kerning data for a pair of glyphs.

Data Fields
int16_t	glyph2	Index of second glyph.
int8_t	kerning	Signed number of pixels to advance after drawing the glyph (scaled by 127 / point_size)

◆ rdpq_font_t

struct rdpq_font_t

A font64 file containing a font.

Data Fields
char	magic[3]	Magic header (FONT_MAGIC)
uint8_t	version	Version number (1)
uint32_t	flags	Flags.
uint32_t	point_size	Point size of the font.
int32_t	ascent	Ascent (number of pixels above baseline)
int32_t	descent	Descent (number of pixels below baseline)
int32_t	line_gap	Line gap of the font (spacing between descent and ascent)
int32_t	space_width	Width of the space character.
int16_t	ellipsis_width	Width of the ellipsis character.
uint16_t	ellipsis_glyph	Index of the ellipsis glyph.
uint16_t	ellipsis_reps	Number of ellipsis glyphs to draw.
uint16_t	ellipsis_advance	Advance of the ellipsis character.
uint32_t	num_ranges	Number of ranges in the font.
uint32_t	num_glyphs	Number of glyphs in the font.
uint32_t	num_atlases	Number of atlases in the font.
uint32_t	num_kerning	Number of kerning pairs in the font.
uint32_t	num_styles	Number of styles in the font.
style_t	builtin_style	Default style for the font.
range_t *	ranges	Array of ranges.
sparse_range_t *	sparse_range	Sparse table of glyph indices.
glyph_t *	glyphs	Array of glyphs.
glyph_krange_t *	glyphs_kranges	Array of glyph kerning ranges.
atlas_t *	atlases	Array of atlases.
kerning_t *	kerning	Array of kerning pairs.
style_t *	styles	Array of styles.

Enumeration Type Documentation

◆ fonttype_t

enum fonttype_t

Type of the font.

Enumerator
FONT_TYPE_ALIASED	Aliased font (I4)
FONT_TYPE_MONO	Mono font (CI4, which are 4 1bpp layers)
FONT_TYPE_MONO_OUTLINE	Mono font with outline (CI4, which are 2 2bpp layers)
FONT_TYPE_ALIASED_OUTLINE	Aliased font with outline (IA8)
FONT_TYPE_BITMAP	Bitmap font (RGBA32/RGBA16/CI4/CI8)

Function Documentation

◆ __rdpq_font_glyph()

int16_t __rdpq_font_glyph	(	const rdpq_font_t *	font,
		uint32_t	codepoint
	)

Look up a glyph in a font.

Parameters

font	Font to look up the glyph in
codepoint	Unicode codepoint of the glyph

Returns: int16_t Index of the glyph in the font, or -1 if not found

◆ __rdpq_font_glyph_metrics()

void __rdpq_font_glyph_metrics	(	const rdpq_font_t *	fnt,
		int16_t	index,
		float *	xadvance,
		int8_t *	xoff,
		int8_t *	xoff2,
		bool *	has_kerning,
		uint8_t *	atlas_id
	)

inline

Get glyph metrics for a font glyph.