lv_font.h

Defines

LV_FONT_DECLARE(font_name)

Typedefs

typedef _lv_font_glyph_format_t lv_font_glyph_format_t
typedef _lv_font_subpx_t lv_font_subpx_t
typedef _lv_font_kerning_t lv_font_kerning_t

Enums

enum _lv_font_glyph_format_t

The font format.

Values:

enumerator LV_FONT_GLYPH_FORMAT_NONE

Maybe not visible Legacy simple formats

enumerator LV_FONT_GLYPH_FORMAT_A1

1 bit per pixel

enumerator LV_FONT_GLYPH_FORMAT_A2

2 bit per pixel

enumerator LV_FONT_GLYPH_FORMAT_A4

4 bit per pixel

enumerator LV_FONT_GLYPH_FORMAT_A8

8 bit per pixel

enumerator LV_FONT_GLYPH_FORMAT_IMAGE

Image format Advanced formats

enumerator LV_FONT_GLYPH_FORMAT_VECTOR

Vectorial format

enumerator LV_FONT_GLYPH_FORMAT_SVG

SVG format

enumerator LV_FONT_GLYPH_FORMAT_CUSTOM

Custom format

enum _lv_font_subpx_t

The bitmaps might be upscaled by 3 to achieve subpixel rendering.

Values:

enumerator LV_FONT_SUBPX_NONE
enumerator LV_FONT_SUBPX_HOR
enumerator LV_FONT_SUBPX_VER
enumerator LV_FONT_SUBPX_BOTH
enum _lv_font_kerning_t

Adjust letter spacing for specific character pairs.

Values:

enumerator LV_FONT_KERNING_NORMAL
enumerator LV_FONT_KERNING_NONE

Functions

const void *lv_font_get_glyph_bitmap(lv_font_glyph_dsc_t *g_dsc, uint32_t letter, lv_draw_buf_t *draw_buf)

Return with the bitmap of a font.

Parameters:
  • g_dsc -- the glyph descriptor including which font to use etc.

  • letter -- a UNICODE character code

  • draw_buf -- a draw buffer that can be used to store the bitmap of the glyph, it's OK not to use it.

Returns:

pointer to the glyph's data. It can be a draw buffer for bitmap fonts or an image source for imgfonts.

bool lv_font_get_glyph_dsc(const lv_font_t *font, lv_font_glyph_dsc_t *dsc_out, uint32_t letter, uint32_t letter_next)

Get the descriptor of a glyph

Parameters:
  • font -- pointer to font

  • dsc_out -- store the result descriptor here

  • letter -- a UNICODE letter code

  • letter_next -- the next letter after letter. Used for kerning

Returns:

true: descriptor is successfully loaded into dsc_out. false: the letter was not found, no data is loaded to dsc_out

uint16_t lv_font_get_glyph_width(const lv_font_t *font, uint32_t letter, uint32_t letter_next)

Get the width of a glyph with kerning

Parameters:
  • font -- pointer to a font

  • letter -- a UNICODE letter

  • letter_next -- the next letter after letter. Used for kerning

Returns:

the width of the glyph

static inline int32_t lv_font_get_line_height(const lv_font_t *font)

Get the line height of a font. All characters fit into this height

Parameters:

font -- pointer to a font

Returns:

the height of a font

void lv_font_set_kerning(lv_font_t *font, lv_font_kerning_t kerning)

Configure the use of kerning information stored in a font

Parameters:
  • font -- pointer to a font

  • kerning -- LV_FONT_KERNING_NORMAL (default) or LV_FONT_KERNING_NONE

static inline const lv_font_t *lv_font_default(void)

Just a wrapper around LV_FONT_DEFAULT because it might be more convenient to use a function in some cases

Returns:

pointer to LV_FONT_DEFAULT

Variables

const lv_font_t lv_font_montserrat_14
struct lv_font_glyph_dsc_t
#include <lv_font.h>

Describes the properties of a glyph.

Public Members

const lv_font_t *resolved_font

Pointer to a font where the glyph was actually found after handling fallbacks

uint16_t adv_w

The glyph needs this space. Draw the next glyph after this width.

uint16_t box_w

Width of the glyph's bounding box

uint16_t box_h

Height of the glyph's bounding box

int16_t ofs_x

x offset of the bounding box

int16_t ofs_y

y offset of the bounding box

lv_font_glyph_format_t format

Font format of the glyph see @lv_font_glyph_format_t

uint8_t is_placeholder

Glyph is missing. But placeholder will still be displayed

uint32_t glyph_index

The index of the glyph in the font file. Used by the font cache

lv_cache_entry_t *entry

The cache entry of the glyph draw data. Used by the font cache

struct _lv_font_t
#include <lv_font.h>

Describe the properties of a font

Public Members

bool (*get_glyph_dsc)(const lv_font_t*, lv_font_glyph_dsc_t*, uint32_t letter, uint32_t letter_next)

Get a glyph's descriptor from a font

const void *(*get_glyph_bitmap)(lv_font_glyph_dsc_t*, uint32_t, lv_draw_buf_t*)

Get a glyph's bitmap from a font

void (*release_glyph)(const lv_font_t*, lv_font_glyph_dsc_t*)

Release a glyph

int32_t line_height

The real line height where any text fits

int32_t base_line

Base line measured from the top of the line_height

uint8_t subpx

An element of lv_font_subpx_t

uint8_t kerning

An element of lv_font_kerning_t

int8_t underline_position

Distance between the top of the underline and base line (< 0 means below the base line)

int8_t underline_thickness

Thickness of the underline

const void *dsc

Store implementation specific or run_time data or caching here

const lv_font_t *fallback

Fallback font for missing glyph. Resolved recursively

void *user_data

Custom user data for font.