# embedded-mogeefont

![Unlike many other pixel fonts, MogeeFont maximizes screen space efficiency by incorporating glyphs of variable width alongside kerning tables and ligatures.](mogeefont.png)

MogeeFont was originally created by Nadya Kuzmina for a pixel game that had to fit on a 64×64 pixel screen. You can read about [the history of MogeeFont here](https://nadyakuzmina.com/story-of-mogeefont.html). This crate brings the font to embedded systems, it should be used together with [embedded-graphics](https://github.com/embedded-graphics/embedded-graphics) and [embedded-text](https://github.com/embedded-graphics/embedded-text).

![Embedded](embedded.jpg)

# Usage

```rust
use embedded_text::{style::TextBoxStyle, TextBox};
use embedded_mogeefont::MogeeTextStyle;
use embedded_graphics::{
  geometry::{Size, Point},
  mock_display::MockDisplay,
  pixelcolor::BinaryColor,
  primitives::Rectangle,
  Drawable,
};

let mut display = MockDisplay::new();
let character_style = MogeeTextStyle::new(BinaryColor::On);
let textbox_style = TextBoxStyle::default();
let textbox_bounds = Rectangle::new(Point::zero(), Size::new(42, 22));
let textbox = TextBox::with_textbox_style(
   "Hello, world!",
   textbox_bounds,
   character_style,
   textbox_style,
);
textbox.draw(&mut display).unwrap();
assert_eq!(
  display,
  MockDisplay::from_pattern(&[
    "                                          ",
    "#  #     # #                       #   # #",
    "#  #     # #                       #   # #",
    "#  #  ## # # ##      # # # ##  ##  #  ## #",
    "#### # # # # # #     # # # # # # # # # # #",
    "#  # ### # # # #     # # # # # # # # # # #",
    "#  # #   # # # #     # # # # # #   # # #  ",
    "#  #  ## # #  ## #   ## #   ## #   # ##  #",
    "                 #                        ",
    "                #                         ",
  ]),
);
```

# Developing

This code includes files from the original [MogeeFont](https://github.com/kuzminadya/mogeefont) repo using a git submodule. Make sure to run `git submodule init` and `git submodule update` to bring in the submodule contents.

The easiest way to start hacking on the code is to [install nix](https://nixos.org/download/#download-nix), enable [nix flakes](https://wiki.nixos.org/wiki/Flakes), then run:

```sh
nix develop
```

To preview the font in the browser with the [embedded-graphics-web-simulator](https://github.com/rahul-thakoor/embedded-graphics-web-simulator), run:

```sh
cargo run --target wasm32-unknown-unknown -p specimen
```

If you want it to recompile on changes, you can use `cargo-watch`:

```sh
cargo watch -x 'run --target wasm32-unknown-unknown -p specimen'
```

To regenerate the font files for the ASCII charset from the sources:

```sh
cargo run -p generate-font -- --charset ascii
```

This command loads the pngs for glyphs, and also extracts the kerning tables from the original source code (using [tree-sitter-elm](https://github.com/elm-tooling/tree-sitter-elm) to parse the Elm module). It then assembles the sprite atlas and generates the Rust code.

# Font Design

You can find the source images in the `mogeefont/font` directory. All the glyphs are named according to the Unicode code points they represent. Ligaturues are named with mulitple code points separated by underscores.

The nix shell comes with [the rx pixel editor](https://rx.cloudhead.io), which can be used to edit glyph images. It only supports 8-bit RGBA PNGs, so you may need to convert the images to this format before editing them with `mogrify`:

```sh
mogrify -depth 8 -define png:color-type=6 mogeefont/font/*.png
```