allegro_schrift/README.md

# allegro_schrift
Drop-in replacement for Allegro_TTF that contains libschrift, instead of using FreeType2.

It is 100% API compatible with the vanilla TrueType addon. Compile Allegro with these files inside of `/addons/ttf`.

![Comparison between FreeType2 and schrift when running Allegro's ex_ttf demo](comparison.png)

Pros:
- It doesn't require NT 6 kernel calls
- It doesn't dynamically link against hundreds of thousands of lines of ugly corporate-backed C code you can't read
  - Our addon is only a couple or few hundred lines, and libschrift is less than 2,000. They're compiled together.  
  The original Allegro_TTF is over 1,000 lines (for a good reason) and has a relatively massive dependency weight (for a stupid reason).

Caveats:
- Pre-stretching is not implemented.
- The entire caching system is gone, fonts are baked to textures immediately and no further. This makes supporting some languages with this add-on inconvenient, or impossible.  
If your usecase doesn't need every fancy rendering feature and can use schrift, you probably aren't supporting enough characters and languages to need on-the-fly caching, so we consider this an acceptable tradeoff.
    - The `cache_text` setting in allegro5.cfg is now reused to determine what glyphs can be rendered at all. `skip_cache_misses` has no effect.  
    When `cache_text` is undefined, the [Latin](https://en.wikipedia.org/wiki/ASCII), [Germanic, and Romance](https://en.wikipedia.org/wiki/Latin_Extended-A) alphabets will be generated by default. (not necessarily 32 - 255)
    - **TODO** Alternatively, the developer can force a custom range of unicode characters to be generated using a new parameter in the `al_load_ttf_font` function.
- Kerning, per-character advance and offsets, and other features which are exposed by libschrift are not currently implemented, but doing so is possible. See the above comparison screenshot.