Add font fallback functionality

Author: hasenbanck

.gitignore

@@ -2,6 +2,7 @@
 target/
 
 # Korangar
+korangar/archive/data/font/*
 korangar/client/
 korangar/data.grf
 korangar/rdata.grf

Cargo.lock

@@ -46,6 +46,7 @@ ron = "0.8"
 serde = "1.0"
 spin_sleep = "1.3"
 syn = "2.0"
+sys-locale = "0.3"
 tokio = { version = "1.42", default-features = false }
 walkdir = "2.5"
 wgpu = "23.0"

Cargo.toml

@@ -36,6 +36,7 @@ rayon = { workspace = true }
 ron = { workspace = true }
 serde = { workspace = true }
 spin_sleep = { workspace = true }
+sys-locale = { workspace = true }
 walkdir = { workspace = true }
 wgpu = { workspace = true }
 winit = { workspace = true }

korangar/Cargo.toml

@@ -5,17 +5,20 @@ included in the distributed font file. Currently, we use "Noto Sans", which incl
 and Greek alphabets. If you need to support a different alphabet, then you need to use a different font (for example
 "Noto Sans Japanese"). Since Korangar uses a pre-assembled font map, that includes all glyphs of a font file in
 a multichannel signed distance field (MSDF) representation, you need to create a such a font map and also a font map
-description file in the CSV format:
+description file in the CSV format. We support having fallback fonts, so if for example the primary fonts doesn't have
+a specific glyph, the fallback font is tried. Multiple fallback fonts are supported. The final height of all font maps
+combined must not exceed 8192 pixel.
 
 1. Use [msdfgen](https://github.com/Chlumsky/msdfgen) to create the font map image and the description file in the
-   CSV format.
+   CSV format. The image width must be 8192 pixel wide and the height should be chosen to be a multiple of 4 and have a
+   minimal size, so that all glyphs are included and no space is wasted. This is needed to properly merge multiple fonts
+   into one font map.
    ```sh
-   msdf-atlas-gen -allglyphs -pxrange 6 -size 32 -yorigin top -type mtsdf -format png -font NotoSans.ttf -csv NotoSans.csv -imageout NotoSans.png
+   msdf-atlas-gen -allglyphs -pxrange 6 -size 32 -yorigin top -dimensions 8192 4096 -type msdf -format png -font NotoSans.ttf -csv NotoSans.csv -imageout NotoSans.png
    ```
 2. Copy the original font file and also the generated PNG and CSV file into the `archive/data/font` folder.
-3. Optionally compress the CSV file with gzip:
+3. Compress the CSV file with gzip:
    ```sh
    gzip NotoSans.csv
    ```
-4. Update the `FONT_FILE_PATH`, `FONT_MAP_DESCRIPTION_FILE_PATH`, `FONT_MAP_FILE_PATH` and `FONT_FAMILY_NAME` in the
-   `korangar/src/loaders/font/mod.rs` file.
+4. Update the DEFAULT_FONTS list inside the `korangar/src/interface/application.rs` file.

korangar/archive/data/font/NotoSans.csv.gz

@@ -1,4 +1,5 @@
 use std::marker::ConstParamTy;
+use std::sync::Arc;
 
 #[cfg(feature = "debug")]
 use korangar_debug::logging::{print_debug, Colorize};
@@ -22,6 +23,8 @@ use crate::input::{MouseInputMode, UserEvent};
 use crate::loaders::{FontLoader, FontSize, Scaling};
 use crate::renderer::InterfaceRenderer;
 
+const DEFAULT_FONTS: &[&str] = &["NotoSans", "NotoSansKR"];
+
 impl korangar_interface::application::ColorTrait for Color {
     fn is_transparent(&self) -> bool {
         const TRANSPARENCY_THRESHOLD: f32 = 0.999;
@@ -177,6 +180,7 @@ impl<const KIND: InternalThemeKind> PrototypeElement<InterfaceSettings> for Them
 
 #[derive(Serialize, Deserialize)]
 struct InterfaceSettingsStorage {
+    fonts: Vec<String>,
     menu_theme: String,
     main_theme: String,
     game_theme: String,
@@ -185,12 +189,14 @@ struct InterfaceSettingsStorage {
 
 impl Default for InterfaceSettingsStorage {
     fn default() -> Self {
+        let fonts = Vec::from_iter(DEFAULT_FONTS.iter().map(|font| font.to_string()));
         let main_theme = "client/themes/main.ron".to_string();
         let menu_theme = "client/themes/menu.ron".to_string();
         let game_theme = "client/themes/game.ron".to_string();
         let scaling = Scaling::new(1.0);
 
         Self {
+            fonts,
             main_theme,
             menu_theme,
             game_theme,
@@ -231,6 +237,7 @@ impl InterfaceSettingsStorage {
 
 #[derive(PrototypeElement)]
 pub struct InterfaceSettings {
+    fonts: Vec<String>,
     #[name("Main theme")]
     pub main_theme: ThemeSelector<{ InternalThemeKind::Main }>,
     #[name("Menu theme")]
@@ -245,19 +252,21 @@ pub struct InterfaceSettings {
 impl InterfaceSettings {
     pub fn load_or_default() -> Self {
         let InterfaceSettingsStorage {
+            fonts,
             menu_theme,
             main_theme,
             game_theme,
             scaling,
         } = InterfaceSettingsStorage::load_or_default();
 
         let themes = Themes::new(
-            InterfaceTheme::new::<super::theme::DefaultMenu>(&menu_theme),
-            InterfaceTheme::new::<super::theme::DefaultMain>(&main_theme),
+            InterfaceTheme::new::<DefaultMenu>(&menu_theme),
+            InterfaceTheme::new::<DefaultMain>(&main_theme),
             GameTheme::new(&menu_theme),
         );
 
         Self {
+            fonts,
             main_theme: ThemeSelector(main_theme),
             menu_theme: ThemeSelector(menu_theme),
             game_theme: ThemeSelector(game_theme),
@@ -278,6 +287,10 @@ impl InterfaceSettings {
     pub fn get_game_theme(&self) -> &GameTheme {
         &self.themes.game
     }
+
+    pub fn get_fonts(&self) -> &[String] {
+        &self.fonts
+    }
 }
 
 impl InterfaceSettings {
@@ -317,7 +330,7 @@ impl Application for InterfaceSettings {
     type CustomEvent = UserEvent;
     type DropResource = PartialMove;
     type DropResult = Move;
-    type FontLoader = std::rc::Rc<std::cell::RefCell<FontLoader>>;
+    type FontLoader = Arc<FontLoader>;
     type FontSize = FontSize;
     type MouseInputMode = MouseInputMode;
     type PartialSize = PartialScreenSize;
@@ -343,6 +356,7 @@ impl Application for InterfaceSettings {
 impl Drop for InterfaceSettings {
     fn drop(&mut self) {
         InterfaceSettingsStorage {
+            fonts: self.fonts.to_owned(),
             menu_theme: self.menu_theme.get_file().to_owned(),
             main_theme: self.main_theme.get_file().to_owned(),
             game_theme: self.game_theme.get_file().to_owned(),

korangar/archive/data/font/NotoSans.png

@@ -1,5 +1,4 @@
-use std::cell::RefCell;
-use std::rc::Rc;
+use std::sync::Arc;
 
 use korangar_interface::builder::Unset;
 use korangar_interface::state::PlainRemote;
@@ -33,12 +32,12 @@ impl<Font> ChatBuilder<Unset, Font> {
 }
 
 impl<Messages> ChatBuilder<Messages, Unset> {
-    pub fn with_font_loader(self, font_loader: Rc<RefCell<FontLoader>>) -> ChatBuilder<Messages, Rc<RefCell<FontLoader>>> {
+    pub fn with_font_loader(self, font_loader: Arc<FontLoader>) -> ChatBuilder<Messages, Arc<FontLoader>> {
         ChatBuilder { font_loader, ..self }
     }
 }
 
-impl ChatBuilder<PlainRemote<Vec<ChatMessage>>, Rc<RefCell<FontLoader>>> {
+impl ChatBuilder<PlainRemote<Vec<ChatMessage>>, Arc<FontLoader>> {
     /// Take the builder and turn it into a [`Chat`].
     ///
     /// NOTE: This method is only available if

korangar/archive/data/font/README.md

@@ -1,7 +1,6 @@
 mod builder;
 
-use std::cell::RefCell;
-use std::rc::Rc;
+use std::sync::Arc;
 
 use korangar_interface::application::{Application, FontSizeTraitExt};
 use korangar_interface::elements::{Element, ElementState};
@@ -22,7 +21,7 @@ use crate::renderer::InterfaceRenderer;
 
 pub struct Chat {
     messages: PlainRemote<Vec<ChatMessage>>,
-    font_loader: Rc<RefCell<FontLoader>>,
+    font_loader: Arc<FontLoader>,
     state: ElementState<InterfaceSettings>,
 }
 
@@ -55,7 +54,6 @@ impl Element<InterfaceSettings> for Chat {
         for message in self.messages.get().iter() {
             height += self
                 .font_loader
-                .borrow_mut()
                 .get_text_dimensions(
                     &message.text,
                     theme.chat.font_size.get().scaled(application.get_scaling()),

korangar/src/interface/application.rs

@@ -1,5 +1,4 @@
-use std::cell::RefCell;
-use std::rc::Rc;
+use std::sync::Arc;
 
 use derive_new::new;
 use korangar_interface::elements::{ButtonBuilder, ElementWrap, InputFieldBuilder, ScrollView};
@@ -26,7 +25,7 @@ pub struct ChatMessage {
 #[derive(new)]
 pub struct ChatWindow {
     messages: PlainRemote<Vec<ChatMessage>>,
-    font_loader: Rc<RefCell<FontLoader>>,
+    font_loader: Arc<FontLoader>,
 }
 
 impl ChatWindow {

korangar/src/interface/elements/miscellanious/chat/builder.rs

@@ -0,0 +1,108 @@
+use std::io::{Cursor, Read};
+use std::sync::Arc;
+
+use cosmic_text::fontdb::{Source, ID};
+use cosmic_text::FontSystem;
+use flate2::bufread::GzDecoder;
+use hashbrown::HashMap;
+use image::{ImageFormat, ImageReader, RgbaImage};
+#[cfg(feature = "debug")]
+use korangar_debug::logging::{print_debug, Colorize, Timer};
+use korangar_util::FileLoader;
+
+use crate::loaders::font::font_map_descriptor::parse_glyphs;
+use crate::loaders::font::GlyphCoordinate;
+use crate::loaders::GameFileLoader;
+
+const FONT_FOLDER_PATH: &str = "data\\font";
+
+pub(crate) struct FontFile {
+    pub(crate) ids: Vec<ID>,
+    pub(crate) font_map: RgbaImage,
+    pub(crate) glyphs: Arc<HashMap<u16, GlyphCoordinate>>,
+}
+
+impl FontFile {
+    pub(crate) fn new(name: &str, game_file_loader: &GameFileLoader, font_system: &mut FontSystem) -> Option<Self> {
+        #[cfg(feature = "debug")]
+        let timer = Timer::new_dynamic(format!("load font: {}", name.magenta()));
+
+        let font_base_path = format!("{}\\{}", FONT_FOLDER_PATH, name);
+        let ttf_file_path = format!("{}.ttf", font_base_path);
+        let map_file_path = format!("{}.png", font_base_path);
+        let map_description_file_path = format!("{}.csv.gz", font_base_path);
+
+        let Ok(font_data) = game_file_loader.get(&ttf_file_path) else {
+            #[cfg(feature = "debug")]
+            print_debug!("[{}] failed to load font file '{}'", "error".red(), ttf_file_path.magenta());
+            return None;
+        };
+
+        let ids = font_system.db_mut().load_font_source(Source::Binary(Arc::new(font_data)));
+
+        let Ok(font_map_data) = game_file_loader.get(&map_file_path) else {
+            #[cfg(feature = "debug")]
+            print_debug!("[{}] failed to load font map file '{}'", "error".red(), map_file_path.magenta());
+            return None;
+        };
+
+        let font_map_reader = ImageReader::with_format(Cursor::new(font_map_data), ImageFormat::Png);
+
+        let Ok(font_map_decoder) = font_map_reader.decode() else {
+            #[cfg(feature = "debug")]
+            print_debug!("[{}] failed to decode font map '{}'", "error".red(), map_file_path.magenta());
+            return None;
+        };
+
+        let font_map_rgba_image = font_map_decoder.into_rgba8();
+        let font_map_width = font_map_rgba_image.width();
+        let font_map_height = font_map_rgba_image.height();
+
+        let Ok(mut font_description_data) = game_file_loader.get(&map_description_file_path) else {
+            #[cfg(feature = "debug")]
+            print_debug!(
+                "[{}] failed to load font map description file '{}'",
+                "error".red(),
+                map_description_file_path.magenta()
+            );
+            return None;
+        };
+
+        let mut decoder = GzDecoder::new(&font_description_data[..]);
+        let mut data = Vec::with_capacity(font_description_data.len() * 2);
+
+        if let Err(_err) = decoder.read_to_end(&mut data) {
+            #[cfg(feature = "debug")]
+            print_debug!(
+                "[{}] failed to decompress font map description file '{}': {:?}",
+                "error".red(),
+                map_description_file_path.magenta(),
+                _err
+            );
+            return None;
+        }
+
+        font_description_data = data;
+
+        let Ok(font_description_content) = String::from_utf8(font_description_data) else {
+            #[cfg(feature = "debug")]
+            print_debug!(
+                "[{}] invalid UTF-8 text data found in font map description file '{}'",
+                "error".red(),
+                map_description_file_path.magenta()
+            );
+            return None;
+        };
+
+        let glyphs = parse_glyphs(font_description_content, font_map_width, font_map_height);
+
+        #[cfg(feature = "debug")]
+        timer.stop();
+
+        Some(Self {
+            ids: Vec::from_iter(ids),
+            font_map: font_map_rgba_image,
+            glyphs: Arc::new(glyphs),
+        })
+    }
+}

korangar/src/interface/elements/miscellanious/chat/mod.rs

@@ -25,11 +25,7 @@ struct Bounds {
     top: f64,
 }
 
-pub(crate) fn parse_glyph_cache(
-    font_description_content: String,
-    font_map_width: u32,
-    font_map_height: u32,
-) -> HashMap<u16, GlyphCoordinate> {
+pub(crate) fn parse_glyphs(font_description_content: String, font_map_width: u32, font_map_height: u32) -> HashMap<u16, GlyphCoordinate> {
     let font_map_width = font_map_width as f32;
     let font_map_height = font_map_height as f32;