LVGL use custom font(e.g. freetype), some letters are not fully displayed(e.g. j,g)

Bug (archived)
1

What MCU/Processor/Board and compiler are you using?

arm

What do you experience?

I use freetype instead of default font, but I fount that some letters are not fully displayed(e.g. j,g).

Maybe font’s base_line has problem. For example, Only I set label’s height to 35, and use 32 size font, it displays normally.

This means that the height of the label must be larger than the font size.

And I can’t set textarea text height, so it can’t display normally.

What do you expect?

None

Code to reproduce

    lv_obj_t* textArea = lv_textarea_create(lv_src_act(), NULL);
  
    lv_obj_set_style_local_radius(textArea, LV_TEXTAREA_PART_BG, LV_STATE_DEFAULT, 8);
    lv_obj_set_style_local_pad_bottom(textArea, LV_TEXTAREA_PART_BG, LV_STATE_DEFAULT, 26);
    lv_obj_set_style_local_pad_top(textArea, LV_TEXTAREA_PART_BG, LV_STATE_DEFAULT, 26);
    lv_obj_set_style_local_pad_left(textArea, LV_TEXTAREA_PART_BG, LV_STATE_DEFAULT, 8);
    lv_obj_set_style_local_pad_right(textArea, LV_TEXTAREA_PART_BG, LV_STATE_DEFAULT, 8);
   
    lv_obj_set_style_local_text_color(textArea, LV_TEXTAREA_PART_BG, LV_STATE_DEFAULT, lv_color_make(0xE4, 0xE4, 0xE4));
    lv_obj_set_style_local_text_font(textArea, LV_TEXTAREA_PART_BG, LV_STATE_DEFAULT, FontProvider::GetInstance().GetFont(28)/*custom font*/);

    lv_obj_set_height(textArea, 80/*pad + font size*/);

Screenshot and/or video

微信图片_20200824103437
微信图片_202008241034373648×2736 1.09 MB

2

font size is 32? top and bottom pads are 26px? So set the height to 84.

3

Please check my sample code again, font size is 28.

4

From sample code there is no data related to font. I can see only custom function called with argument of 28 number, which tells nothing about font size.

By the way, font structure has member called line_height or use function lv_font_get_line_height which will return it. Try to use it instead of raw undefined numbers. For example, internal font lv_font_montserrat_18 as name says, shall have the size 18px, but in fact the real (required) height of the font is 21 pixels.

1 Like
5

I think @BesitzeRuf is right.

See how lv_lib_freetype calculates line_height.