I want to determine whether the displayed content exists in the font library generated myself

How-to
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1

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Description

I want to determine whether the displayed content exists in the font library generated myself

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

esp32

What LVGL version are you using?

v8.0+

What do you want to achieve?

I want to determine whether the displayed content exists in the font library generated myself

What have you tried so far?

I thought of a method, because the encoding is written in utf-8 strings, but there is a unicode encoding array unicode_list in the font library, so I want to convert utf-8 into unicode encoding first, and then compare with unicode_list, come Determine whether the current font library supports displaying the content

Code to reproduce

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2

There were some related changes since v8.2 (available in master). So I suggest updating to the latest master version.

You can do this:

lv_font_glyph_dsc_t dsc;
bool ret = lv_font_get_glyph_dsc(font, &dsc,  letter, 0);
if(ret == false) printf("not found\n");

I’m not sure if it’s relevant in your case but some font engines (e.g. FreeType) supports returning a □ when the glyph is not found. In this case lv_font_get_glyph_dsc returns true but dsc->is_placeholder is set to 1. However, this feature is not supported in default built in font engine.