lv_font_fmt_txt.h

Enums

enum lv_font_fmt_txt_cmap_type_t

Format of font character map.

Values:

enumerator LV_FONT_FMT_TXT_CMAP_FORMAT0_FULL

enumerator LV_FONT_FMT_TXT_CMAP_SPARSE_FULL

enumerator LV_FONT_FMT_TXT_CMAP_FORMAT0_TINY

enumerator LV_FONT_FMT_TXT_CMAP_SPARSE_TINY

enum lv_font_fmt_txt_bitmap_format_t

Bitmap formats

Values:

enumerator LV_FONT_FMT_TXT_PLAIN

enumerator LV_FONT_FMT_TXT_COMPRESSED

enumerator LV_FONT_FMT_TXT_COMPRESSED_NO_PREFILTER

Functions

const void *lv_font_get_bitmap_fmt_txt(lv_font_glyph_dsc_t *g_dsc, lv_draw_buf_t *draw_buf)

Used as get_glyph_bitmap callback in lvgl's native font format if the font is uncompressed.

参数:

g_dsc -- the glyph descriptor including which font to use, which supply the glyph_index and format.
draw_buf -- a draw buffer that can be used to store the bitmap of the glyph, it's OK not to use it.

返回:

pointer to an A8 bitmap (not necessarily bitmap_out) or NULL if unicode_letter not found

bool lv_font_get_glyph_dsc_fmt_txt(const lv_font_t *font, lv_font_glyph_dsc_t *dsc_out, uint32_t unicode_letter, uint32_t unicode_letter_next)

Used as get_glyph_dsc callback in lvgl's native font format if the font is uncompressed.

参数:

font -- pointer to font
dsc_out -- store the result descriptor here
unicode_letter -- a UNICODE letter code
unicode_letter_next -- the unicode letter succeeding the letter under test

返回:

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

struct lv_font_fmt_txt_glyph_dsc_t

#include <lv_font_fmt_txt.h>

This describes a glyph.

Public Members

uint32_t bitmap_index: Start index of the bitmap. A font can be max 4 GB.

uint32_t adv_w: Draw the next glyph after this width. 28.4 format (real_value * 16 is stored).

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. Measured from the top of the line

struct lv_font_fmt_txt_cmap_t

#include <lv_font_fmt_txt.h>

Map codepoints to a glyph_dscs Several formats are supported to optimize memory usage See https://github.com/lvgl/lv_font_conv/blob/master/doc/font_spec.md

Public Members

uint32_t range_start: First Unicode character for this range

uint16_t range_length: Number of Unicode characters related to this range. Last Unicode character = range_start + range_length - 1

uint16_t glyph_id_start: First glyph ID (array index of glyph_dsc) for this range

const uint16_t *unicode_list

const void *glyph_id_ofs_list: if(type == LV_FONT_FMT_TXT_CMAP_FORMAT0_...) it's uint8_t * if(type == LV_FONT_FMT_TXT_CMAP_SPARSE_...) it's uint16_t *

uint16_t list_length: Length of unicode_list and/or glyph_id_ofs_list

lv_font_fmt_txt_cmap_type_t type: Type of this character map

struct lv_font_fmt_txt_kern_pair_t

#include <lv_font_fmt_txt.h>

A simple mapping of kern values from pairs

Public Members

const void *glyph_ids

const int8_t *values

uint32_t pair_cnt

uint32_t glyph_ids_size

struct lv_font_fmt_txt_kern_classes_t

#include <lv_font_fmt_txt.h>

More complex but more optimal class based kern value storage

Public Members

const int8_t *class_pair_values

const uint8_t *left_class_mapping

const uint8_t *right_class_mapping

uint8_t left_class_cnt

uint8_t right_class_cnt

struct lv_font_fmt_txt_dsc_t

Public Members

const uint8_t *glyph_bitmap

const lv_font_fmt_txt_glyph_dsc_t *glyph_dsc

const lv_font_fmt_txt_cmap_t *cmaps

const void *kern_dsc: Store kerning values. Can be lv_font_fmt_txt_kern_pair_t * orlv_font_kern_classes_fmt_txt_t * depending onkern_classes`

uint16_t kern_scale

uint16_t cmap_num

uint16_t bpp

uint16_t kern_classes

uint16_t bitmap_format