Make file system loader serializable 📚

5 files changed, 75 insertions, 60 deletions

diff --git a/bench/src/bench.rs b/bench/src/bench.rs
index 1b160bdc..052ef5d6 100644
--- a/bench/src/bench.rs
+++ b/bench/src/bench.rs
@@ -17,7 +17,7 @@ const CASES: &[&str] = &["full/coma.typ", "text/basic.typ"];
 
 fn benchmarks(c: &mut Criterion) {
     let mut loader = FsLoader::new();
-    loader.search_dir(FONT_DIR);
+    loader.search_path(FONT_DIR);
 
     let mut env = Env::new(loader);
 
diff --git a/src/env/fs.rs b/src/env/fs.rs
index 98378722..5f18191b 100644
--- a/src/env/fs.rs
+++ b/src/env/fs.rs
@@ -5,6 +5,7 @@ use std::path::{Path, PathBuf};
 use std::rc::Rc;
 
 use memmap2::Mmap;
+use serde::{Deserialize, Serialize};
 use ttf_parser::{name_id, Face};
 use walkdir::WalkDir;
 
@@ -14,10 +15,11 @@ use crate::font::{FaceInfo, FontStretch, FontStyle, FontVariant, FontWeight};
 /// Loads fonts and resources from the local file system.
 ///
 /// _This is only available when the `fs` feature is enabled._
-#[derive(Default, Debug, Clone)]
+#[derive(Default, Debug, Clone, Serialize, Deserialize)]
 pub struct FsLoader {
     faces: Vec<FaceInfo>,
-    paths: Vec<PathBuf>,
+    files: Vec<PathBuf>,
+    #[serde(skip)]
     cache: FileCache,
 }
 
@@ -30,7 +32,7 @@ impl FsLoader {
     pub fn new() -> Self {
         Self {
             faces: vec![],
-            paths: vec![],
+            files: vec![],
             cache: HashMap::new(),
         }
     }
@@ -64,19 +66,22 @@ impl FsLoader {
         let windir =
             std::env::var("WINDIR").unwrap_or_else(|_| "C:\\Windows".to_string());
 
-        self.search_dir(Path::new(&windir).join("Fonts"));
+        self.search_path(Path::new(&windir).join("Fonts"));
 
         if let Some(roaming) = dirs::config_dir() {
-            self.search_dir(roaming.join("Microsoft\\Windows\\Fonts"));
+            self.search_path(roaming.join("Microsoft\\Windows\\Fonts"));
         }
 
         if let Some(local) = dirs::cache_dir() {
-            self.search_dir(local.join("Microsoft\\Windows\\Fonts"));
+            self.search_path(local.join("Microsoft\\Windows\\Fonts"));
         }
     }
 
-    /// Search for all fonts in a directory.
-    pub fn search_dir(&mut self, dir: impl AsRef<Path>) {
+    /// Search for all fonts at a path.
+    ///
+    /// If the path is a directory, all contained fonts will be searched for
+    /// recursively.
+    pub fn search_path(&mut self, dir: impl AsRef<Path>) {
         let walk = WalkDir::new(dir)
             .follow_links(true)
             .sort_by(|a, b| a.file_name().cmp(b.file_name()))
@@ -102,8 +107,9 @@ impl FsLoader {
     ///
     /// The file may form a font collection and contain multiple font faces,
     /// which will then all be indexed.
-    pub fn search_file(&mut self, path: impl AsRef<Path>) -> io::Result<()> {
+    fn search_file(&mut self, path: impl AsRef<Path>) -> io::Result<()> {
         let path = path.as_ref();
+        let path = path.strip_prefix(".").unwrap_or(path);
 
         let file = File::open(path)?;
         let mmap = unsafe { Mmap::map(&file)? };
@@ -149,10 +155,15 @@ impl FsLoader {
 
         // Merge with an existing entry for the same family name.
         self.faces.push(FaceInfo { family, variant, index });
-        self.paths.push(path.to_owned());
+        self.files.push(path.to_owned());
 
         Ok(())
     }
+
+    /// Paths to font files, parallel to [`faces()`](Self::faces).
+    pub fn files(&self) -> &[PathBuf] {
+        &self.files
+    }
 }
 
 impl Loader for FsLoader {
@@ -161,7 +172,7 @@ impl Loader for FsLoader {
     }
 
     fn load_face(&mut self, idx: usize) -> Option<Buffer> {
-        load(&mut self.cache, &self.paths[idx])
+        load(&mut self.cache, &self.files[idx])
     }
 
     fn load_file(&mut self, url: &str) -> Option<Buffer> {
@@ -169,6 +180,7 @@ impl Loader for FsLoader {
     }
 }
 
+/// Load from the file system using a cache.
 fn load(cache: &mut FileCache, path: &Path) -> Option<Buffer> {
     match cache.entry(path.to_owned()) {
         Entry::Occupied(entry) => entry.get().clone(),
@@ -186,10 +198,9 @@ mod tests {
     #[test]
     fn test_index_font_dir() {
         let mut loader = FsLoader::new();
-        loader.search_dir("fonts");
-        loader.paths.sort();
+        loader.search_path("fonts");
 
-        assert_eq!(loader.paths, &[
+        assert_eq!(loader.files, &[
             Path::new("fonts/EBGaramond-Bold.ttf"),
             Path::new("fonts/EBGaramond-BoldItalic.ttf"),
             Path::new("fonts/EBGaramond-Italic.ttf"),
diff --git a/src/font.rs b/src/font.rs
index 52912664..5a83f6c4 100644
--- a/src/font.rs
+++ b/src/font.rs
@@ -25,7 +25,7 @@ impl Face {
         // SAFETY:
         // - The slices's location is stable in memory:
         //   - We don't move the underlying vector
-        //   - Nobody else can move it since we haved a strong ref to the `Rc`.
+        //   - Nobody else can move it since we have a strong ref to the `Rc`.
         // - The internal static lifetime is not leaked because its rewritten
         //   to the self-lifetime in `ttf()`.
         let slice: &'static [u8] =
@@ -151,19 +151,20 @@ impl Em {
 }
 
 /// Properties of a single font face.
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub struct FaceInfo {
     /// The typographic font family this face is part of.
     pub family: String,
     /// Properties that distinguish this face from other faces in the same
     /// family.
+    #[serde(flatten)]
     pub variant: FontVariant,
     /// The collection index in the font file.
     pub index: u32,
 }
 
 /// Properties that distinguish a face from other faces in the same family.
-#[derive(Default, Debug, Copy, Clone, PartialEq)]
+#[derive(Default, Debug, Copy, Clone, PartialEq, Serialize, Deserialize)]
 pub struct FontVariant {
     /// The style of the face (normal / italic / oblique).
     pub style: FontStyle,
@@ -183,6 +184,7 @@ impl FontVariant {
 /// The style of a font face.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
 #[derive(Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
 pub enum FontStyle {
     /// The default style.
     Normal,
@@ -347,6 +349,7 @@ impl Debug for FontWeight {
 
 /// The width of a font face.
 #[derive(Copy, Clone, PartialEq, PartialOrd, Serialize, Deserialize)]
+#[serde(transparent)]
 pub struct FontStretch(f32);
 
 impl FontStretch {
diff --git a/src/main.rs b/src/main.rs
index 05827681..fa98d4c5 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -35,7 +35,7 @@ fn main() -> anyhow::Result<()> {
     let src = fs::read_to_string(src_path).context("Failed to read from source file.")?;
 
     let mut loader = FsLoader::new();
-    loader.search_dir("fonts");
+    loader.search_path("fonts");
     loader.search_system();
 
     let mut env = Env::new(loader);
diff --git a/tests/typeset.rs b/tests/typeset.rs
index afd0d055..5e48494d 100644
--- a/tests/typeset.rs
+++ b/tests/typeset.rs
@@ -63,7 +63,7 @@ fn main() {
     }
 
     let mut loader = FsLoader::new();
-    loader.search_dir(FONT_DIR);
+    loader.search_path(FONT_DIR);
 
     let mut env = Env::new(loader);
 
@@ -122,6 +122,12 @@ impl Args {
     }
 }
 
+struct Panic {
+    pos: Pos,
+    lhs: Option<Value>,
+    rhs: Option<Value>,
+}
+
 fn test(
     env: &mut Env,
     src_path: &Path,
@@ -302,12 +308,6 @@ fn parse_metadata(src: &str, map: &LineMap) -> (Option<bool>, DiagSet) {
     (compare_ref, diags)
 }
 
-struct Panic {
-    pos: Pos,
-    lhs: Option<Value>,
-    rhs: Option<Value>,
-}
-
 fn register_helpers(scope: &mut Scope, panics: Rc<RefCell<Vec<Panic>>>) {
     pub fn args(_: &mut EvalContext, args: &mut FuncArgs) -> Value {
         let repr = pretty(args);
@@ -344,7 +344,7 @@ fn print_diag(diag: &Diag, map: &LineMap, lines: u32) {
     println!("{}: {}-{}: {}", diag.level, start, end, diag.message);
 }
 
-fn draw(env: &Env, frames: &[Frame], pixel_per_pt: f32) -> Pixmap {
+fn draw(env: &Env, frames: &[Frame], dpi: f32) -> Pixmap {
     let pad = Length::pt(5.0);
 
     let height = pad + frames.iter().map(|l| l.size.height + pad).sum::<Length>();
@@ -355,8 +355,8 @@ fn draw(env: &Env, frames: &[Frame], pixel_per_pt: f32) -> Pixmap {
             .max_by(|a, b| a.partial_cmp(&b).unwrap())
             .unwrap_or_default();
 
-    let pixel_width = (pixel_per_pt * width.to_pt() as f32) as u32;
-    let pixel_height = (pixel_per_pt * height.to_pt() as f32) as u32;
+    let pixel_width = (dpi * width.to_pt() as f32) as u32;
+    let pixel_height = (dpi * height.to_pt() as f32) as u32;
     if pixel_width > 4000 || pixel_height > 4000 {
         panic!(
             "overlarge image: {} by {} ({} x {})",
@@ -365,7 +365,7 @@ fn draw(env: &Env, frames: &[Frame], pixel_per_pt: f32) -> Pixmap {
     }
 
     let mut canvas = Pixmap::new(pixel_width, pixel_height).unwrap();
-    let ts = Transform::from_scale(pixel_per_pt, pixel_per_pt);
+    let ts = Transform::from_scale(dpi, dpi);
     canvas.fill(Color::BLACK);
 
     let mut origin = Point::new(pad, pad);
@@ -391,15 +391,9 @@ fn draw(env: &Env, frames: &[Frame], pixel_per_pt: f32) -> Pixmap {
             let y = pos.y.to_pt() as f32;
             let ts = ts.pre_translate(x, y);
             match element {
-                Element::Text(shaped) => {
-                    draw_text(&mut canvas, env, ts, shaped);
-                }
-                Element::Image(image) => {
-                    draw_image(&mut canvas, env, ts, image);
-                }
-                Element::Geometry(geom) => {
-                    draw_geometry(&mut canvas, ts, geom);
-                }
+                Element::Text(shaped) => draw_text(&mut canvas, env, ts, shaped),
+                Element::Image(image) => draw_image(&mut canvas, env, ts, image),
+                Element::Geometry(geom) => draw_geometry(&mut canvas, ts, geom),
             }
         }
 
@@ -517,32 +511,41 @@ fn convert_typst_fill(fill: Fill) -> Paint<'static> {
 }
 
 fn convert_typst_path(path: &geom::Path) -> tiny_skia::Path {
-    let f = |length: Length| length.to_pt() as f32;
     let mut builder = tiny_skia::PathBuilder::new();
+    let f = |v: Length| v.to_pt() as f32;
     for elem in &path.0 {
         match elem {
-            geom::PathElement::MoveTo(p) => builder.move_to(f(p.x), f(p.y)),
-            geom::PathElement::LineTo(p) => builder.line_to(f(p.x), f(p.y)),
+            geom::PathElement::MoveTo(p) => {
+                builder.move_to(f(p.x), f(p.y));
+            }
+            geom::PathElement::LineTo(p) => {
+                builder.line_to(f(p.x), f(p.y));
+            }
             geom::PathElement::CubicTo(p1, p2, p3) => {
-                builder.cubic_to(f(p1.x), f(p1.y), f(p2.x), f(p2.y), f(p3.x), f(p3.y))
+                builder.cubic_to(f(p1.x), f(p1.y), f(p2.x), f(p2.y), f(p3.x), f(p3.y));
+            }
+            geom::PathElement::ClosePath => {
+                builder.close();
             }
-            geom::PathElement::ClosePath => builder.close(),
         };
     }
     builder.finish().unwrap()
 }
 
+fn convert_usvg_transform(transform: usvg::Transform) -> Transform {
+    let g = |v: f64| v as f32;
+    let usvg::Transform { a, b, c, d, e, f } = transform;
+    Transform::from_row(g(a), g(b), g(c), g(d), g(e), g(f))
+}
+
 fn convert_usvg_fill(fill: &usvg::Fill) -> (Paint<'static>, FillRule) {
     let mut paint = Paint::default();
     paint.anti_alias = true;
 
     match fill.paint {
-        usvg::Paint::Color(color) => paint.set_color_rgba8(
-            color.red,
-            color.green,
-            color.blue,
-            fill.opacity.to_u8(),
-        ),
+        usvg::Paint::Color(usvg::Color { red, green, blue }) => {
+            paint.set_color_rgba8(red, green, blue, fill.opacity.to_u8())
+        }
         usvg::Paint::Link(_) => {}
     }
 
@@ -555,29 +558,27 @@ fn convert_usvg_fill(fill: &usvg::Fill) -> (Paint<'static>, FillRule) {
 }
 
 fn convert_usvg_path(path: &usvg::PathData) -> tiny_skia::Path {
-    let f = |v: f64| v as f32;
     let mut builder = tiny_skia::PathBuilder::new();
+    let f = |v: f64| v as f32;
     for seg in path.iter() {
         match *seg {
-            usvg::PathSegment::MoveTo { x, y } => builder.move_to(f(x), f(y)),
+            usvg::PathSegment::MoveTo { x, y } => {
+                builder.move_to(f(x), f(y));
+            }
             usvg::PathSegment::LineTo { x, y } => {
                 builder.line_to(f(x), f(y));
             }
             usvg::PathSegment::CurveTo { x1, y1, x2, y2, x, y } => {
-                builder.cubic_to(f(x1), f(y1), f(x2), f(y2), f(x), f(y))
+                builder.cubic_to(f(x1), f(y1), f(x2), f(y2), f(x), f(y));
+            }
+            usvg::PathSegment::ClosePath => {
+                builder.close();
             }
-            usvg::PathSegment::ClosePath => builder.close(),
         }
     }
     builder.finish().unwrap()
 }
 
-fn convert_usvg_transform(transform: usvg::Transform) -> Transform {
-    let g = |v: f64| v as f32;
-    let usvg::Transform { a, b, c, d, e, f } = transform;
-    Transform::from_row(g(a), g(b), g(c), g(d), g(e), g(f))
-}
-
 struct WrappedPathBuilder(tiny_skia::PathBuilder);
 
 impl OutlineBuilder for WrappedPathBuilder {