Improved font handling (#6)

* Add system for conveniently loading fonts

* Use the font plugin to only specify a font family, not each font individually

* Simplify querying for a font handle

* Improve structure of font module and exports

* Improve syntax for configuring font folder and make it optional

* Example setup doesn't need the AssetServer anymore

Author: TimJentzsch

Cargo.lock

@@ -11,7 +11,10 @@ categories = ["game-development"]
 exclude = ["assets/**/*", ".github/**/*"]
 
 [dependencies]
+ab_glyph = "0.2.28"
+fontdb = "0.20.0"
 nom = "7.1.3"
+tinyvec = "1.8.0"
 
 [dependencies.bevy]
 version = "0.14"

Cargo.toml

@@ -0,0 +1,5 @@
+# Credits
+
+| Path    | License   |
+| ------- | --------- |
+| `fonts` | `OFL.txt` |

assets/CREDITS.md

@@ -10,21 +10,18 @@ struct TimeMarker;
 
 fn main() {
     App::new()
-        .add_plugins((DefaultPlugins, BbcodePlugin))
+        .add_plugins((DefaultPlugins, BbcodePlugin::new().with_fonts("fonts")))
         .add_systems(Startup, setup)
         .add_systems(Update, update)
         .run();
 }
 
-fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
+fn setup(mut commands: Commands) {
     commands.spawn(Camera2dBundle::default());
 
     commands.spawn(BbcodeBundle::from_content(
         "Time passed: [m=time]0.0[/m] s",
-        BbcodeSettings::new(40., Color::WHITE)
-            .with_regular_font(asset_server.load("fonts/FiraSans-Regular.ttf"))
-            .with_bold_font(asset_server.load("fonts/FiraSans-Bold.ttf"))
-            .with_italic_font(asset_server.load("fonts/FiraSans-Italic.ttf"))
+        BbcodeSettings::new("Fira Sans", 40., Color::WHITE)
             // Register the marker component for the `m=time` tag
             .with_marker("time", TimeMarker),
     ));

assets/fonts/OFL.txt renamed to assets/OFL.txt

@@ -3,19 +3,16 @@ use bevy_mod_bbcode::{BbcodeBundle, BbcodePlugin, BbcodeSettings};
 
 fn main() {
     App::new()
-        .add_plugins((DefaultPlugins, BbcodePlugin))
+        .add_plugins((DefaultPlugins, BbcodePlugin::new().with_fonts("fonts")))
         .add_systems(Startup, setup)
         .run();
 }
 
-fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
+fn setup(mut commands: Commands) {
     commands.spawn(Camera2dBundle::default());
 
     commands.spawn(BbcodeBundle::from_content(
-        "test [b]bold[/b] with [i]italic[/i] and [c=#ff00ff]color[/c]",
-        BbcodeSettings::new(40., Color::WHITE)
-            .with_regular_font(asset_server.load("fonts/FiraSans-Regular.ttf"))
-            .with_bold_font(asset_server.load("fonts/FiraSans-Bold.ttf"))
-            .with_italic_font(asset_server.load("fonts/FiraSans-Italic.ttf")),
+        "test [b]bold with [i]italic[/i][/b] and [c=#ff00ff]color[/c]",
+        BbcodeSettings::new("Fira Sans", 40., Color::WHITE),
     ));
 }

examples/dynamic.rs

@@ -18,46 +18,23 @@ pub(crate) struct Modifiers {
 
 #[derive(Clone, Component)]
 pub struct BbcodeSettings {
+    pub font_family: String,
     pub font_size: f32,
     pub color: Color,
 
-    pub(crate) regular_font: Option<Handle<Font>>,
-    pub(crate) bold_font: Option<Handle<Font>>,
-    pub(crate) italic_font: Option<Handle<Font>>,
-
     pub(crate) modifiers: Modifiers,
 }
 
 impl BbcodeSettings {
-    pub fn new(font_size: f32, color: Color) -> Self {
+    pub fn new<F: Into<String>>(font_family: F, font_size: f32, color: Color) -> Self {
         Self {
+            font_family: font_family.into(),
             font_size,
             color,
-            regular_font: None,
-            bold_font: None,
-            italic_font: None,
             modifiers: Default::default(),
         }
     }
 
-    /// Add a font to use for regular text.
-    pub fn with_regular_font(mut self, handle: Handle<Font>) -> Self {
-        self.regular_font = Some(handle);
-        self
-    }
-
-    /// Add a font to use for bold text.
-    pub fn with_bold_font(mut self, handle: Handle<Font>) -> Self {
-        self.bold_font = Some(handle);
-        self
-    }
-
-    /// Add a font to use for italic text.
-    pub fn with_italic_font(mut self, handle: Handle<Font>) -> Self {
-        self.italic_font = Some(handle);
-        self
-    }
-
     /// Register a marker component for the `[m]` tag.
     pub fn with_marker<N: Into<String>, M: Component + Clone>(
         mut self,

examples/static.rs

@@ -4,7 +4,10 @@ use bevy::{ecs::system::EntityCommands, prelude::*};
 
 use crate::bbcode::{parser::parse_bbcode, BbcodeNode, BbcodeTag};
 
-use super::bbcode::{Bbcode, BbcodeSettings};
+use super::{
+    bbcode::{Bbcode, BbcodeSettings},
+    font::FontRegistry,
+};
 
 #[derive(Debug, Clone)]
 struct BbcodeContext {
@@ -69,9 +72,10 @@ impl BbcodeContext {
 pub fn convert_bbcode(
     mut commands: Commands,
     bbcode_query: Query<(Entity, Ref<Bbcode>, Ref<BbcodeSettings>)>,
+    font_registry: Res<FontRegistry>,
 ) {
     for (entity, bbcode, settings) in bbcode_query.iter() {
-        if !bbcode.is_changed() && !settings.is_changed() {
+        if !bbcode.is_changed() && !settings.is_changed() && !font_registry.is_changed() {
             continue;
         }
 
@@ -100,6 +104,7 @@ pub fn convert_bbcode(
             },
             &settings,
             &nodes,
+            font_registry.as_ref(),
         )
     }
 }
@@ -109,23 +114,26 @@ fn construct_recursively(
     context: BbcodeContext,
     settings: &BbcodeSettings,
     nodes: &Vec<Arc<BbcodeNode>>,
+    font_registry: &FontRegistry,
 ) {
-    let default_font = settings.regular_font.clone().unwrap_or_default();
-
     for node in nodes {
         match **node {
             BbcodeNode::Text(ref text) => {
-                let font = match (context.is_bold, context.is_italic) {
-                    (true, _) => default_font.clone(),
-                    (_, true) => settings
-                        .italic_font
-                        .clone()
-                        .unwrap_or_else(|| default_font.clone()),
-                    (false, false) => settings
-                        .regular_font
-                        .clone()
-                        .unwrap_or_else(|| default_font.clone()),
+                let font_query = fontdb::Query {
+                    families: &[fontdb::Family::Name(&settings.font_family)],
+                    weight: if context.is_bold {
+                        fontdb::Weight::BOLD
+                    } else {
+                        fontdb::Weight::NORMAL
+                    },
+                    stretch: fontdb::Stretch::Normal,
+                    style: if context.is_italic {
+                        fontdb::Style::Italic
+                    } else {
+                        fontdb::Style::Normal
+                    },
                 };
+                let font = font_registry.query_handle(&font_query).unwrap_or_default();
 
                 entity_commands.with_children(|builder| {
                     let mut text_commands = builder.spawn(TextBundle::from_section(
@@ -151,6 +159,7 @@ fn construct_recursively(
                 context.apply_tag(tag),
                 settings,
                 tag.children(),
+                font_registry,
             ),
         }
     }

src/bevy/bbcode.rs

@@ -0,0 +1,5 @@
+mod plugin;
+mod registry;
+
+pub use plugin::FontPlugin;
+pub use registry::FontRegistry;

src/bevy/conversion.rs

@@ -0,0 +1,30 @@
+use bevy::prelude::*;
+
+use super::registry::FontRegistry;
+
+#[derive(Debug)]
+pub struct FontPlugin;
+
+impl Plugin for FontPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<FontRegistry>()
+            .add_systems(Update, update_font_registry);
+    }
+}
+
+/// Track when fonts are loaded, modified or removed and update the font registry accordingly.
+fn update_font_registry(
+    mut font_registry: ResMut<FontRegistry>,
+    mut font_changes: EventReader<AssetEvent<Font>>,
+    font_assets: Res<Assets<Font>>,
+) {
+    for change in font_changes.read() {
+        match *change {
+            AssetEvent::Added { id } => font_registry.add(id, font_assets.as_ref()),
+            AssetEvent::Modified { id } => font_registry.update(id, font_assets.as_ref()),
+            AssetEvent::Removed { id } => font_registry.remove(id),
+            AssetEvent::Unused { id: _ } => {}
+            AssetEvent::LoadedWithDependencies { id: _ } => {}
+        }
+    }
+}