Tiny TTF font engine

Usage

Allow using TrueType fonts LVGL. Based on https://github.com/nothings/stb

When enabled in lv_conf.h with LV_USE_TINY_TTF lv_tiny_ttf_create_data(data, data_size, font_size) can be used to create a TTF font instance at the specified line height. You can then use that font anywhere lv_font_t is accepted.

By default, the TTF or OTF file must be embedded as an array, either in a header, or loaded into RAM in order to function.

However, if LV_TINY_TTF_FILE_SUPPORT is enabled, lv_tiny_ttf_create_file(path, font_size) will also be available, allowing tiny_ttf to stream from a file. The file must remain open the entire time the font is being used.

After a font is created, you can change the font size in pixels by using lv_tiny_ttf_set_size(font, font_size).

By default, a font will use up to 4KB of cache to speed up rendering glyphs. This maximum can be changed by using lv_tiny_ttf_create_data_ex(data, data_size, font_size, cache_size) or lv_tiny_ttf_create_file_ex(path, font_size, cache_size) (when available). The cache size is indicated in bytes.

Example

Open a font with Tiny TTF from data array

#include "../../lv_examples.h"
#if LV_USE_TINY_TTF && LV_BUILD_EXAMPLES

/**
 * Load a font with Tiny_TTF
 */
void lv_example_tiny_ttf_1(void)
{
    extern const uint8_t ubuntu_font[];
    extern const int ubuntu_font_size;

    static lv_font_t font;
    lv_result_t res = lv_tiny_ttf_create_data(&font, ubuntu_font, ubuntu_font_size, 30);
    if(res == LV_RESULT_INVALID) return;

    /*Create style with the new font*/
    static lv_style_t style;
    lv_style_init(&style);
    lv_style_set_text_font(&style, &font);
    lv_style_set_text_align(&style, LV_TEXT_ALIGN_CENTER);

    /*Create a label with the new style*/
    lv_obj_t * label = lv_label_create(lv_screen_active());
    lv_obj_add_style(label, &style, 0);
    lv_label_set_text(label, "Hello world\nI'm a font\ncreated\nwith Tiny TTF");
    lv_obj_center(label);
}
#endif

from ubuntu_font import ubuntu_font
#
# Load a font with Tiny_TTF
#
#Create style with the new font
style = lv.style_t()
style.init()
font = lv.font_t()
lv.tiny_ttf_create_data(font, ubuntu_font, len(ubuntu_font), 30)
style.set_text_font(font)
style.set_text_align(lv.TEXT_ALIGN.CENTER)

# Create a label with the new style
label = lv.label(lv.screen_active())
label.add_style(style, 0)
label.set_text("Hello world\nI'm a font created with Tiny TTF")
label.center()

Load a font with Tiny_TTF from file

#include "../../lv_examples.h"
#if LV_USE_TINY_TTF && LV_TINY_TTF_FILE_SUPPORT && LV_BUILD_EXAMPLES

/**
 * Load a font with Tiny_TTF from file
 */
void lv_example_tiny_ttf_2(void)
{
    static lv_font_t font;
    lv_result_t res = lv_tiny_ttf_create_file(&font, "A:lvgl/examples/libs/tiny_ttf/Ubuntu-Medium.ttf", 30);
    if(res == LV_RESULT_INVALID) return;

    /*Create style with the new font*/
    static lv_style_t style;
    lv_style_init(&style);
    lv_style_set_text_font(&style, &font);
    lv_style_set_text_align(&style, LV_TEXT_ALIGN_CENTER);

    /*Create a label with the new style*/
    lv_obj_t * label = lv_label_create(lv_screen_active());
    lv_obj_add_style(label, &style, 0);
    lv_label_set_text(label, "Hello world\nI'm a font\ncreated\nwith Tiny TTF");
    lv_obj_center(label);
}
#endif

import fs_driver

# needed for dynamic font loading
fs_drv = lv.fs_drv_t()
fs_driver.fs_register(fs_drv, 'S')

# get the directory in which the script is running
try:
    script_path = __file__[:__file__.rfind('/')] if __file__.find('/') >= 0 else '.'
except NameError:
    script_path = ''

#
# Load a font with Tiny_TTF from file
#
# Create style with the new font
style = lv.style_t()
style.init()
font = lv.font_t()
lv.tiny_ttf_create_file(font, "S:" + script_path + "/Ubuntu-Medium.ttf", 30)
style.set_text_font(font)
style.set_text_align(lv.TEXT_ALIGN.CENTER)

# Create a label with the new style
label = lv.label(lv.screen_active())
label.add_style(style, 0)
label.set_text("Hello world\nI'm a font created with Tiny TTF")
label.center()

Change font size with Tiny_TTF

#include "../../lv_examples.h"
#if LV_USE_TINY_TTF && LV_BUILD_EXAMPLES && LV_USE_OBSERVER

static void font_size_observer_cb(lv_subject_t * subject, lv_observer_t * observer);

static lv_subject_t subject_font;
static lv_font_t font;
/**
 * Change font size with Tiny_TTF
 */
void lv_example_tiny_ttf_3(void)
{
    extern const uint8_t ubuntu_font[];
    extern const int ubuntu_font_size;

    lv_subject_init_int(&subject_font, 25);

    /*Create style with the new font*/
    static lv_style_t style;
    lv_style_init(&style);
    lv_result_t res = lv_tiny_ttf_create_data(&font, ubuntu_font, ubuntu_font_size, 25);
    if(res == LV_RESULT_INVALID) return;
    lv_style_set_text_font(&style, &font);
    lv_style_set_text_align(&style, LV_TEXT_ALIGN_CENTER);

    lv_obj_t * slider = lv_slider_create(lv_screen_active());
    lv_obj_center(slider);
    lv_slider_set_range(slider, 5, 50);
    lv_obj_align(slider, LV_ALIGN_BOTTOM_MID, 0, -50);
    lv_slider_bind_value(slider, &subject_font);

    lv_obj_t * slider_label = lv_label_create(lv_screen_active());
    lv_obj_align_to(slider_label, slider, LV_ALIGN_OUT_BOTTOM_MID, 0, 10);
    lv_label_bind_text(slider_label, &subject_font, "%d");

    /*Create a label with the new style*/
    lv_obj_t * label = lv_label_create(lv_screen_active());
    lv_obj_add_style(label, &style, 0);
    lv_obj_set_size(label, LV_SIZE_CONTENT, LV_SIZE_CONTENT);
    lv_label_set_text(label, "Hello world!");
    lv_obj_center(label);

    lv_subject_add_observer(&subject_font, font_size_observer_cb, &style);
}

static void font_size_observer_cb(lv_subject_t * subject, lv_observer_t * observer)
{
    lv_style_t * style = observer->user_data;
    int32_t size = lv_subject_get_int(subject);

    lv_tiny_ttf_set_size(&font, size);

    lv_obj_report_style_change(style);
}
#endif

pass

API

stb_rect_pack.h

stb_truetype_htcw.h