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feat(freetype): support bold and italic (#2824)

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* feat(freetype):support bold and italic

* fix(format): replace code-format.sh with code-format.py

Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>
This commit is contained in:
guoweilkd
2021-11-25 03:19:09 +08:00
committed by GitHub
parent 6791522588
commit 81f7d50c45
9 changed files with 227 additions and 20 deletions
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docs/libs/freetype.md
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@@ -1,6 +1,6 @@
```eval_rst
.. include:: /header.rst
:github_url: |github_link_base|/libs/bmp.md
:github_url: |github_link_base|/libs/freetype.md
```
# FreeType support
@@ -19,11 +19,33 @@ Interface to [FreeType](https://www.freetype.org/) to generate font bitmaps run
Enable `LV_USE_FREETYPE` in `lv_conf.h`.
See the examples below.
To cache the glyphs from the opened fonts set `LV_FREETYPE_CACHE_SIZE >= 0` and then use the following macros for detailed configuration:
1. `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.
1. `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.
1. `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 fonts size 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 macro to set:
1. `FT_FONT_STYLE_NORMAL`:default style.
1. `FT_FONT_STYLE_ITALIC`:Italic style
1. `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
```eval_rst
.. include:: ../../examples/libs/freetype/index.rst
```
## Learn more
- FreeType [tutorial](https://www.freetype.org/freetype2/docs/tutorial/step1.html)
- LVGL's [font interface](https://docs.lvgl.io/v7/en/html/overview/font.html#add-a-new-font-engine)