Implement `font::load` command in `iced_native`

1 files changed, 266 insertions, 204 deletions

diff --git a/wgpu/src/text.rs b/wgpu/src/text.rs
index 083d9d2b..cdfcd576 100644
--- a/wgpu/src/text.rs
+++ b/wgpu/src/text.rs
@@ -5,108 +5,37 @@ use iced_native::alignment;
 use iced_native::{Color, Font, Rectangle, Size};
 
 use rustc_hash::{FxHashMap, FxHashSet};
+use std::borrow::Cow;
 use std::cell::RefCell;
 use std::hash::{BuildHasher, Hash, Hasher};
+use std::sync::Arc;
 use twox_hash::RandomXxHashBuilder64;
 
 #[allow(missing_debug_implementations)]
 pub struct Pipeline {
+    system: Option<System>,
     renderers: Vec<glyphon::TextRenderer>,
     atlas: glyphon::TextAtlas,
-    cache: glyphon::SwashCache<'static>,
-    measurement_cache: RefCell<Cache>,
-    render_cache: Cache,
     layer: usize,
 }
 
-struct Cache {
-    entries: FxHashMap<KeyHash, glyphon::Buffer<'static>>,
-    recently_used: FxHashSet<KeyHash>,
-    hasher: RandomXxHashBuilder64,
-}
-
-impl Cache {
-    fn new() -> Self {
-        Self {
-            entries: FxHashMap::default(),
-            recently_used: FxHashSet::default(),
-            hasher: RandomXxHashBuilder64::default(),
-        }
-    }
-
-    fn get(&self, key: &KeyHash) -> Option<&glyphon::Buffer<'static>> {
-        self.entries.get(key)
-    }
-
-    fn allocate(
-        &mut self,
-        key: Key<'_>,
-    ) -> (KeyHash, &mut glyphon::Buffer<'static>) {
-        let hash = {
-            let mut hasher = self.hasher.build_hasher();
-
-            key.content.hash(&mut hasher);
-            (key.size as i32).hash(&mut hasher);
-            key.font.hash(&mut hasher);
-            (key.bounds.width as i32).hash(&mut hasher);
-            (key.bounds.height as i32).hash(&mut hasher);
-            key.color.into_rgba8().hash(&mut hasher);
-
-            hasher.finish()
-        };
+#[ouroboros::self_referencing]
+struct System {
+    fonts: glyphon::FontSystem,
 
-        if !self.entries.contains_key(&hash) {
-            let metrics =
-                glyphon::Metrics::new(key.size as i32, (key.size * 1.2) as i32);
+    #[borrows(fonts)]
+    #[not_covariant]
+    cache: glyphon::SwashCache<'this>,
 
-            let mut buffer = glyphon::Buffer::new(&FONT_SYSTEM, metrics);
+    #[borrows(fonts)]
+    #[not_covariant]
+    measurement_cache: RefCell<Cache<'this>>,
 
-            buffer.set_size(key.bounds.width as i32, key.bounds.height as i32);
-            buffer.set_text(
-                key.content,
-                glyphon::Attrs::new().family(to_family(key.font)).color({
-                    let [r, g, b, a] = key.color.into_linear();
-
-                    glyphon::Color::rgba(
-                        (r * 255.0) as u8,
-                        (g * 255.0) as u8,
-                        (b * 255.0) as u8,
-                        (a * 255.0) as u8,
-                    )
-                }),
-            );
-
-            let _ = self.entries.insert(hash, buffer);
-        }
-
-        let _ = self.recently_used.insert(hash);
-
-        (hash, self.entries.get_mut(&hash).unwrap())
-    }
-
-    fn trim(&mut self) {
-        self.entries
-            .retain(|key, _| self.recently_used.contains(key));
-
-        self.recently_used.clear();
-    }
+    #[borrows(fonts)]
+    #[not_covariant]
+    render_cache: Cache<'this>,
 }
 
-#[derive(Debug, Clone, Copy)]
-struct Key<'a> {
-    content: &'a str,
-    size: f32,
-    font: Font,
-    bounds: Size,
-    color: Color,
-}
-
-type KeyHash = u64;
-
-// TODO: Share with `iced_graphics`
-static FONT_SYSTEM: once_cell::sync::Lazy<glyphon::FontSystem> =
-    once_cell::sync::Lazy::new(glyphon::FontSystem::new);
-
 impl Pipeline {
     pub fn new(
         device: &wgpu::Device,
@@ -114,15 +43,41 @@ impl Pipeline {
         format: wgpu::TextureFormat,
     ) -> Self {
         Pipeline {
+            system: Some(
+                SystemBuilder {
+                    fonts: glyphon::FontSystem::new(),
+                    cache_builder: |fonts| glyphon::SwashCache::new(fonts),
+                    measurement_cache_builder: |_| RefCell::new(Cache::new()),
+                    render_cache_builder: |_| Cache::new(),
+                }
+                .build(),
+            ),
             renderers: Vec::new(),
             atlas: glyphon::TextAtlas::new(device, queue, format),
-            cache: glyphon::SwashCache::new(&FONT_SYSTEM),
-            measurement_cache: RefCell::new(Cache::new()),
-            render_cache: Cache::new(),
             layer: 0,
         }
     }
 
+    pub fn load_font(&mut self, bytes: Cow<'static, [u8]>) {
+        let heads = self.system.take().unwrap().into_heads();
+
+        let (locale, mut db) = heads.fonts.into_locale_and_db();
+
+        db.load_font_source(glyphon::fontdb::Source::Binary(Arc::new(
+            bytes.to_owned(),
+        )));
+
+        self.system = Some(
+            SystemBuilder {
+                fonts: glyphon::FontSystem::new_with_locale_and_db(locale, db),
+                cache_builder: |fonts| glyphon::SwashCache::new(fonts),
+                measurement_cache_builder: |_| RefCell::new(Cache::new()),
+                render_cache_builder: |_| Cache::new(),
+            }
+            .build(),
+        );
+    }
+
     pub fn prepare(
         &mut self,
         device: &wgpu::Device,
@@ -132,93 +87,100 @@ impl Pipeline {
         scale_factor: f32,
         target_size: Size<u32>,
     ) {
-        if self.renderers.len() <= self.layer {
-            self.renderers
-                .push(glyphon::TextRenderer::new(device, queue));
-        }
-
-        let renderer = &mut self.renderers[self.layer];
-
-        let keys: Vec<_> = sections
-            .iter()
-            .map(|section| {
-                let (key, _) = self.render_cache.allocate(Key {
-                    content: section.content,
-                    size: section.size * scale_factor,
-                    font: section.font,
-                    bounds: Size {
-                        width: section.bounds.width * scale_factor,
-                        height: section.bounds.height * scale_factor,
+        self.system.as_mut().unwrap().with_mut(|fields| {
+            if self.renderers.len() <= self.layer {
+                self.renderers
+                    .push(glyphon::TextRenderer::new(device, queue));
+            }
+
+            let renderer = &mut self.renderers[self.layer];
+
+            let keys: Vec<_> = sections
+                .iter()
+                .map(|section| {
+                    let (key, _) = fields.render_cache.allocate(
+                        fields.fonts,
+                        Key {
+                            content: section.content,
+                            size: section.size * scale_factor,
+                            font: section.font,
+                            bounds: Size {
+                                width: section.bounds.width * scale_factor,
+                                height: section.bounds.height * scale_factor,
+                            },
+                            color: section.color,
+                        },
+                    );
+
+                    key
+                })
+                .collect();
+
+            let bounds = glyphon::TextBounds {
+                left: (bounds.x * scale_factor) as i32,
+                top: (bounds.y * scale_factor) as i32,
+                right: ((bounds.x + bounds.width) * scale_factor) as i32,
+                bottom: ((bounds.y + bounds.height) * scale_factor) as i32,
+            };
+
+            let text_areas: Vec<_> = sections
+                .iter()
+                .zip(keys.iter())
+                .map(|(section, key)| {
+                    let buffer = fields
+                        .render_cache
+                        .get(key)
+                        .expect("Get cached buffer");
+
+                    let x = section.bounds.x * scale_factor;
+                    let y = section.bounds.y * scale_factor;
+
+                    let (total_lines, max_width) = buffer
+                        .layout_runs()
+                        .enumerate()
+                        .fold((0, 0.0), |(_, max), (i, buffer)| {
+                            (i + 1, buffer.line_w.max(max))
+                        });
+
+                    let total_height =
+                        total_lines as f32 * section.size * 1.2 * scale_factor;
+
+                    let left = match section.horizontal_alignment {
+                        alignment::Horizontal::Left => x,
+                        alignment::Horizontal::Center => x - max_width / 2.0,
+                        alignment::Horizontal::Right => x - max_width,
+                    };
+
+                    let top = match section.vertical_alignment {
+                        alignment::Vertical::Top => y,
+                        alignment::Vertical::Center => y - total_height / 2.0,
+                        alignment::Vertical::Bottom => y - total_height,
+                    };
+
+                    glyphon::TextArea {
+                        buffer,
+                        left: left as i32,
+                        top: top as i32,
+                        bounds,
+                    }
+                })
+                .collect();
+
+            renderer
+                .prepare(
+                    device,
+                    queue,
+                    &mut self.atlas,
+                    glyphon::Resolution {
+                        width: target_size.width,
+                        height: target_size.height,
                     },
-                    color: section.color,
-                });
-
-                key
-            })
-            .collect();
-
-        let bounds = glyphon::TextBounds {
-            left: (bounds.x * scale_factor) as i32,
-            top: (bounds.y * scale_factor) as i32,
-            right: ((bounds.x + bounds.width) * scale_factor) as i32,
-            bottom: ((bounds.y + bounds.height) * scale_factor) as i32,
-        };
-
-        let text_areas: Vec<_> = sections
-            .iter()
-            .zip(keys.iter())
-            .map(|(section, key)| {
-                let buffer =
-                    self.render_cache.get(key).expect("Get cached buffer");
-
-                let x = section.bounds.x * scale_factor;
-                let y = section.bounds.y * scale_factor;
-
-                let (total_lines, max_width) = buffer
-                    .layout_runs()
-                    .enumerate()
-                    .fold((0, 0.0), |(_, max), (i, buffer)| {
-                        (i + 1, buffer.line_w.max(max))
-                    });
-
-                let total_height =
-                    total_lines as f32 * section.size * 1.2 * scale_factor;
-
-                let left = match section.horizontal_alignment {
-                    alignment::Horizontal::Left => x,
-                    alignment::Horizontal::Center => x - max_width / 2.0,
-                    alignment::Horizontal::Right => x - max_width,
-                };
-
-                let top = match section.vertical_alignment {
-                    alignment::Vertical::Top => y,
-                    alignment::Vertical::Center => y - total_height / 2.0,
-                    alignment::Vertical::Bottom => y - total_height,
-                };
-
-                glyphon::TextArea {
-                    buffer,
-                    left: left as i32,
-                    top: top as i32,
-                    bounds,
-                }
-            })
-            .collect();
-
-        renderer
-            .prepare(
-                device,
-                queue,
-                &mut self.atlas,
-                glyphon::Resolution {
-                    width: target_size.width,
-                    height: target_size.height,
-                },
-                &text_areas,
-                glyphon::Color::rgb(0, 0, 0),
-                &mut self.cache,
-            )
-            .expect("Prepare text sections");
+                    &text_areas,
+                    glyphon::Color::rgb(0, 0, 0),
+                    fields.cache,
+                )
+                .expect("Prepare text sections");
+        });
     }
 
     pub fn render(
@@ -251,7 +213,10 @@ impl Pipeline {
 
     pub fn end_frame(&mut self) {
         self.renderers.truncate(self.layer);
-        self.render_cache.trim();
+        self.system
+            .as_mut()
+            .unwrap()
+            .with_render_cache_mut(|cache| cache.trim());
 
         self.layer = 0;
     }
@@ -263,24 +228,29 @@ impl Pipeline {
         font: Font,
         bounds: Size,
     ) -> (f32, f32) {
-        let mut measurement_cache = self.measurement_cache.borrow_mut();
-
-        let (_, paragraph) = measurement_cache.allocate(Key {
-            content,
-            size: size,
-            font,
-            bounds,
-            color: Color::BLACK,
-        });
+        self.system.as_ref().unwrap().with(|fields| {
+            let mut measurement_cache = fields.measurement_cache.borrow_mut();
+
+            let (_, paragraph) = measurement_cache.allocate(
+                fields.fonts,
+                Key {
+                    content,
+                    size: size,
+                    font,
+                    bounds,
+                    color: Color::BLACK,
+                },
+            );
 
-        let (total_lines, max_width) = paragraph
-            .layout_runs()
-            .enumerate()
-            .fold((0, 0.0), |(_, max), (i, buffer)| {
-                (i + 1, buffer.line_w.max(max))
-            });
+            let (total_lines, max_width) = paragraph
+                .layout_runs()
+                .enumerate()
+                .fold((0, 0.0), |(_, max), (i, buffer)| {
+                    (i + 1, buffer.line_w.max(max))
+                });
 
-        (max_width, size * 1.2 * total_lines as f32)
+            (max_width, size * 1.2 * total_lines as f32)
+        })
     }
 
     pub fn hit_test(
@@ -292,23 +262,31 @@ impl Pipeline {
         point: iced_native::Point,
         _nearest_only: bool,
     ) -> Option<Hit> {
-        let mut measurement_cache = self.measurement_cache.borrow_mut();
-
-        let (_, paragraph) = measurement_cache.allocate(Key {
-            content,
-            size: size,
-            font,
-            bounds,
-            color: Color::BLACK,
-        });
+        self.system.as_ref().unwrap().with(|fields| {
+            let mut measurement_cache = fields.measurement_cache.borrow_mut();
+
+            let (_, paragraph) = measurement_cache.allocate(
+                fields.fonts,
+                Key {
+                    content,
+                    size: size,
+                    font,
+                    bounds,
+                    color: Color::BLACK,
+                },
+            );
 
-        let cursor = paragraph.hit(point.x as i32, point.y as i32)?;
+            let cursor = paragraph.hit(point.x as i32, point.y as i32)?;
 
-        Some(Hit::CharOffset(cursor.index))
+            Some(Hit::CharOffset(cursor.index))
+        })
     }
 
     pub fn trim_measurement_cache(&mut self) {
-        self.measurement_cache.borrow_mut().trim();
+        self.system
+            .as_mut()
+            .unwrap()
+            .with_measurement_cache_mut(|cache| cache.borrow_mut().trim());
     }
 }
 
@@ -322,3 +300,87 @@ fn to_family(font: Font) -> glyphon::Family<'static> {
         Font::Monospace => glyphon::Family::Monospace,
     }
 }
+
+struct Cache<'a> {
+    entries: FxHashMap<KeyHash, glyphon::Buffer<'a>>,
+    recently_used: FxHashSet<KeyHash>,
+    hasher: RandomXxHashBuilder64,
+}
+
+impl<'a> Cache<'a> {
+    fn new() -> Self {
+        Self {
+            entries: FxHashMap::default(),
+            recently_used: FxHashSet::default(),
+            hasher: RandomXxHashBuilder64::default(),
+        }
+    }
+
+    fn get(&self, key: &KeyHash) -> Option<&glyphon::Buffer<'a>> {
+        self.entries.get(key)
+    }
+
+    fn allocate(
+        &mut self,
+        fonts: &'a glyphon::FontSystem,
+        key: Key<'_>,
+    ) -> (KeyHash, &mut glyphon::Buffer<'a>) {
+        let hash = {
+            let mut hasher = self.hasher.build_hasher();
+
+            key.content.hash(&mut hasher);
+            (key.size as i32).hash(&mut hasher);
+            key.font.hash(&mut hasher);
+            (key.bounds.width as i32).hash(&mut hasher);
+            (key.bounds.height as i32).hash(&mut hasher);
+            key.color.into_rgba8().hash(&mut hasher);
+
+            hasher.finish()
+        };
+
+        if !self.entries.contains_key(&hash) {
+            let metrics =
+                glyphon::Metrics::new(key.size as i32, (key.size * 1.2) as i32);
+            let mut buffer = glyphon::Buffer::new(&fonts, metrics);
+
+            buffer.set_size(key.bounds.width as i32, key.bounds.height as i32);
+            buffer.set_text(
+                key.content,
+                glyphon::Attrs::new().family(to_family(key.font)).color({
+                    let [r, g, b, a] = key.color.into_linear();
+
+                    glyphon::Color::rgba(
+                        (r * 255.0) as u8,
+                        (g * 255.0) as u8,
+                        (b * 255.0) as u8,
+                        (a * 255.0) as u8,
+                    )
+                }),
+            );
+
+            let _ = self.entries.insert(hash, buffer);
+        }
+
+        let _ = self.recently_used.insert(hash);
+
+        (hash, self.entries.get_mut(&hash).unwrap())
+    }
+
+    fn trim(&mut self) {
+        self.entries
+            .retain(|key, _| self.recently_used.contains(key));
+
+        self.recently_used.clear();
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+struct Key<'a> {
+    content: &'a str,
+    size: f32,
+    font: Font,
+    bounds: Size,
+    color: Color,
+}
+
+type KeyHash = u64;