Cruddy hacked-together owning Font struct

Cargo.toml

@@ -17,5 +17,6 @@ anyhow = "1"
 bytemuck = "1"
 canary_types = { path = "crates/types" }
 lyon = "1"
+ouroboros = "^0.15"
 parking_lot = "0.12"
 wasmtime = "0.38"

src/text.rs

@@ -9,8 +9,9 @@ use allsorts::outline::OutlineBuilder;
 use allsorts::pathfinder_geometry::{line_segment::LineSegment2F, vector::Vector2F};
 use allsorts::tables::{glyf::GlyfTable, loca::LocaTable};
 use allsorts::tables::{FontTableProvider, SfntVersion};
-use allsorts::{tag, Font};
+use allsorts::{tag, Font as AllsortsFont};
 use lyon::path::Path;
+use ouroboros::self_referencing;
 
 const TEXT_SCALE: f32 = 0.0001;
 
@@ -19,7 +20,7 @@ pub struct GlyphCache {
 }
 
 impl GlyphCache {
-    pub fn new(font: &mut Font<DynamicFontTableProvider>) -> Self {
+    pub fn new(font: &AllsortsFont<DynamicFontTableProvider>) -> Self {
         let glyph_num = font.num_glyphs();
         let mut glyphs = Vec::with_capacity(glyph_num as usize);
 
@@ -127,6 +128,43 @@ pub struct GlyphMesh {
     indices: Vec<MeshIndex>,
 }
 
+#[self_referencing]
+pub struct Font {
+    file_buffer: Vec<u8>,
+
+    #[borrows(file_buffer)]
+    #[covariant]
+    read_scope: ReadScope<'this>,
+
+    #[borrows(read_scope)]
+    #[not_covariant]
+    font_data: FontData<'this>,
+
+    #[borrows(font_data)]
+    #[covariant]
+    inner: AllsortsFont<DynamicFontTableProvider<'this>>,
+}
+
+impl Font {
+    pub fn load(file_buffer: Vec<u8>) -> Self {
+        FontBuilder {
+            file_buffer,
+            read_scope_builder: |buffer| ReadScope::new(buffer),
+            font_data_builder: |scope| scope.read::<FontData<'_>>().unwrap(),
+            inner_builder: |font_data| {
+                AllsortsFont::new(font_data.table_provider(0).unwrap())
+                    .unwrap()
+                    .unwrap()
+            },
+        }
+        .build()
+    }
+
+    pub fn create_glyph_cache(&self) -> GlyphCache {
+        GlyphCache::new(self.borrow_inner())
+    }
+}
+
 pub struct DummyText {
     vertices: Vec<MeshVertex>,
     indices: Vec<MeshIndex>,
@@ -136,26 +174,28 @@ impl Default for DummyText {
     fn default() -> Self {
         let script = tag::LATN;
         let buffer = include_bytes!("linja-pona-4.9.otf");
-        let buffer = buffer.as_slice();
-        let scope = ReadScope::new(&buffer);
-        let font_file = scope.read::<FontData<'_>>().unwrap();
-        let provider = font_file.table_provider(0).unwrap();
-        let mut font = Font::new(provider).unwrap().unwrap();
-        let mut cache = GlyphCache::new(&mut font);
         let text = "toki o! nimi mi li [_mun_alasa_sona]. toki+pona li pona.";
-        let glyphs = font.map_glyphs(&text, script, MatchingPresentation::Required);
+        let mut font = Font::load(buffer.to_vec());
+        let mut cache = font.create_glyph_cache();
+
+        let glyphs = font
+            .with_inner_mut(|font| font.map_glyphs(&text, script, MatchingPresentation::Required));
 
         let lang_tag = None;
         let features = allsorts::gsub::Features::default();
         let kerning = true;
-        let infos = font
-            .shape(glyphs, script, lang_tag, &features, kerning)
-            .unwrap();
+        let infos = font.with_inner_mut(|font| {
+            font.shape(glyphs, script, lang_tag, &features, kerning)
+                .unwrap()
+        });
 
         let direction = TextDirection::LeftToRight;
         let vertical = false;
-        let mut layout = GlyphLayout::new(&mut font, &infos, direction, vertical);
-        let positions = layout.glyph_positions().unwrap();
+
+        let positions = font.with_inner_mut(|font| {
+            let mut layout = GlyphLayout::new(font, &infos, direction, vertical);
+            layout.glyph_positions().unwrap()
+        });
 
         let mut mesh = Self {
             vertices: Vec::new(),