Unicode font support (#587)

![image](https://github.com/agbrs/agb/assets/460842/52dcd161-d8e4-4588-8f3e-c8dd8c2540aa)

Doesn't correctly handle accents or modifiers like that. Ligatures are
also not supported. But does correctly render any character directly in
the font :)

- [x] Changelog updated / no changelog update needed

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Initial unicode support for font rendering.
+
 ### Fixed
 
 - Export the `dma` module correctly so you can write the types from it and use it in more complex cases.

agb-image-converter/src/font_loader.rs

@@ -4,6 +4,7 @@ use quote::quote;
 use proc_macro2::TokenStream;
 
 struct LetterData {
+    character: char,
     width: usize,
     height: usize,
     xmin: i32,
@@ -27,9 +28,11 @@ pub fn load_font(font_data: &[u8], pixels_per_em: f32) -> TokenStream {
     let line_height = line_metrics.new_line_size as i32;
     let mut ascent = line_metrics.ascent as i32;
 
-    let letters: Vec<_> = (0..128)
-        .map(|i| font.rasterize(char::from_u32(i).unwrap(), pixels_per_em))
-        .map(|(metrics, bitmap)| {
+    let mut letters: Vec<_> = font
+        .chars()
+        .iter()
+        .map(|(&c, _)| (c, font.rasterize(c, pixels_per_em)))
+        .map(|(c, (metrics, bitmap))| {
             let width = metrics.width;
             let height = metrics.height;
 
@@ -48,6 +51,7 @@ pub fn load_font(font_data: &[u8], pixels_per_em: f32) -> TokenStream {
                 .collect();
 
             LetterData {
+                character: c,
                 width,
                 height,
                 rendered,
@@ -58,6 +62,8 @@ pub fn load_font(font_data: &[u8], pixels_per_em: f32) -> TokenStream {
         })
         .collect();
 
+    letters.sort_unstable_by_key(|letter| letter.character);
+
     let maximum_above_line = letters
         .iter()
         .map(|x| (x.height as i32 + x.ymin))
@@ -69,6 +75,7 @@ pub fn load_font(font_data: &[u8], pixels_per_em: f32) -> TokenStream {
     }
 
     let font = letters.iter().map(|letter_data| {
+        let character = letter_data.character;
         let data_raw = ByteString(&letter_data.rendered);
         let height = letter_data.height as u8;
         let width = letter_data.width as u8;
@@ -78,6 +85,7 @@ pub fn load_font(font_data: &[u8], pixels_per_em: f32) -> TokenStream {
 
         quote!(
             display::FontLetter::new(
+                #character,
                 #width,
                 #height,
                 #data_raw,

agb/examples/font/OFL.txt

@@ -0,0 +1,94 @@
+Copyright (c) 2021, TakWolf (https://takwolf.com),
+with Reserved Font Name 'Ark Pixel'.
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+https://openfontlicense.org
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded,
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.

agb/examples/object_text_render.rs

@@ -15,7 +15,8 @@ extern crate alloc;
 
 use core::fmt::Write;
 
-const FONT: Font = include_font!("examples/font/yoster.ttf", 12);
+static FONT: Font = include_font!("examples/font/ark-pixel-10px-proportional-ja.ttf", 10);
+
 #[agb::entry]
 fn entry(gba: agb::Gba) -> ! {
     main(gba);
@@ -42,7 +43,7 @@ fn main(mut gba: agb::Gba) -> ! {
     let player_name = "You";
     let _ = writeln!(
             wr,
-            "Woah!{change2} {player_name}! {change1}Hey there! I have a bunch of text I want to show you. However, you will find that the amount of text I can display is limited. Who'd have thought! Good thing that my text system supports scrolling! It only took around 20 jank versions to get here!",
+            "Woah!{change2} {player_name}! {change1}こんにちは! I have a bunch of text I want to show you. However, you will find that the amount of text I can display is limited. Who'd have thought! Good thing that my text system supports scrolling! It only took around 20 jank versions to get here!",
             change2 = ChangeColour::new(2),
             change1 = ChangeColour::new(1),
         );

agb/examples/text_render.rs

@@ -11,7 +11,7 @@ use agb::{
 
 use core::fmt::Write;
 
-const FONT: Font = include_font!("examples/font/yoster.ttf", 12);
+static FONT: Font = include_font!("examples/font/ark-pixel-10px-proportional-ja.ttf", 10);
 
 #[agb::entry]
 fn main(mut gba: agb::Gba) -> ! {
@@ -47,7 +47,7 @@ fn main(mut gba: agb::Gba) -> ! {
     let mut renderer = FONT.render_text((0u16, 3u16));
     let mut writer = renderer.writer(1, 2, &mut bg, &mut vram);
 
-    writeln!(&mut writer, "Hello, World!").unwrap();
+    writeln!(&mut writer, "Hello, World! こんにちは 世界").unwrap();
     writeln!(&mut writer, "This is a font rendering example").unwrap();
 
     writer.commit();

agb/src/display/font.rs

@@ -10,6 +10,7 @@ use super::tiled::{DynamicTile, RegularMap, VRamManager};
 /// Does not support any unicode features.
 /// For usage see the `text_render.rs` example
 pub struct FontLetter {
+    pub(crate) character: char,
     pub(crate) width: u8,
     pub(crate) height: u8,
     pub(crate) data: &'static [u8],
@@ -21,6 +22,7 @@ pub struct FontLetter {
 impl FontLetter {
     #[must_use]
     pub const fn new(
+        character: char,
         width: u8,
         height: u8,
         data: &'static [u8],
@@ -29,6 +31,7 @@ impl FontLetter {
         advance_width: u8,
     ) -> Self {
         Self {
+            character,
             width,
             height,
             data,
@@ -47,14 +50,14 @@ impl FontLetter {
 }
 
 pub struct Font {
-    letters: &'static [FontLetter; 128],
+    letters: &'static [FontLetter],
     line_height: i32,
     ascent: i32,
 }
 
 impl Font {
     #[must_use]
-    pub const fn new(letters: &'static [FontLetter; 128], line_height: i32, ascent: i32) -> Self {
+    pub const fn new(letters: &'static [FontLetter], line_height: i32, ascent: i32) -> Self {
         Self {
             letters,
             line_height,
@@ -63,7 +66,14 @@ impl Font {
     }
 
     pub(crate) fn letter(&self, letter: char) -> &'static FontLetter {
-        &self.letters[letter as usize & (128 - 1)]
+        let letter = self
+            .letters
+            .binary_search_by_key(&letter, |letter| letter.character);
+
+        match letter {
+            Ok(index) => &self.letters[index],
+            Err(_) => &self.letters[0],
+        }
     }
 
     pub(crate) fn ascent(&self) -> i32 {
@@ -269,7 +279,7 @@ impl<'a, 'b> TextRenderer<'b> {
 mod tests {
     use super::*;
     use crate::display::tiled::{TileFormat, TiledMap};
-    const FONT: Font = crate::include_font!("examples/font/yoster.ttf", 12);
+    static FONT: Font = crate::include_font!("examples/font/yoster.ttf", 12);
 
     #[test_case]
     fn font_display(gba: &mut crate::Gba) {