App:Library:LVGL:docs:3rd party libraries:FreeType support

https://docs.lvgl.io/8.2/libs/freetype.html

FreeType support

Interface to FreeType to generate font bitmaps run time.

Install FreeType

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Download Freetype from here make sudo make install

Add FreeType to your project

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Add include path: /usr/include/freetype2 (for GCC: -I/usr/include/freetype2 -L/usr/local/lib) Add library: freetype (for GCC: -L/usr/local/lib -lfreetype)

Usage

英文

自動翻訳

Enable LV_USE_FREETYPE in lv_conf.h. To cache the glyphs from the opened fonts, set LV_FREETYPE_CACHE_SIZE >= 0 and then use the following macros for detailed configuration: LV_FREETYPE_CACHE_SIZE:maximum memory(bytes) used to cache font bitmap, outline, character maps, etc. 0 means use the system default value, less than 0 means disable cache. Note: that this value does not account for managed FT_Face and FT_Size objects. LV_FREETYPE_CACHE_FT_FACES:maximum number of opened FT_Face objects managed by this cache instance.0 means use the system default value. Only useful when LV_FREETYPE_CACHE_SIZE >= 0. LV_FREETYPE_CACHE_FT_SIZES:maximum number of opened FT_Size objects managed by this cache instance. 0 means use the system default value. Only useful when LV_FREETYPE_CACHE_SIZE >= 0. When you are sure that all the used font sizes will not be greater than 256, you can enable LV_FREETYPE_SBIT_CACHE, which is much more memory efficient for small bitmaps. You can use lv_ft_font_init() to create FreeType fonts. It returns true to indicate success, at the same time, the font member of lv_ft_info_t will be filled with a pointer to an LVGL font, and you can use it like any LVGL font. Font style supports bold and italic, you can use the following macros to set: FT_FONT_STYLE_NORMAL:default style. FT_FONT_STYLE_ITALIC:Italic style FT_FONT_STYLE_BOLD:bold style They can be combined.eg:FT_FONT_STYLE_BOLD | FT_FONT_STYLE_ITALIC. Note that, the FreeType extension doesn't use LVGL's file system. You can simply pass the path to the font as usual on your operating system or platform.

Example

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Open a front with FreeType

Learn more

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FreeType tutorial LVGL's font interface

API

英文

自動翻訳

Enums enum LV_FT_FONT_STYLE Values: enumerator FT_FONT_STYLE_NORMAL enumerator FT_FONT_STYLE_ITALIC enumerator FT_FONT_STYLE_BOLD Functions bool lv_freetype_init(uint16_t max_faces, uint16_t max_sizes, uint32_t max_bytes) init freetype library Parameters max_faces -- Maximum number of opened FT_Face objects managed by this cache instance. Use 0 for defaults. max_sizes -- Maximum number of opened FT_Size objects managed by this cache instance. Use 0 for defaults. max_bytes -- Maximum number of bytes to use for cached data nodes. Use 0 for defaults. Note that this value does not account for managed FT_Face and FT_Size objects. Returns true on success, otherwise false. void lv_freetype_destroy(void) Destroy freetype library bool lv_ft_font_init(lv_ft_info_t *info) Creates a font with info parameter specified. Parameters info -- See lv_ft_info_t for details. when success, lv_ft_info_t->font point to the font you created. Returns true on success, otherwise false. void lv_ft_font_destroy(lv_font_t *font) Destroy a font that has been created. Parameters font -- pointer to font. struct lv_ft_info_t Public Members const char *name const void *mem size_t mem_size lv_font_t *font uint16_t weight uint16_t style

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