Extract into separate repository 🧱

1 files changed, 44 insertions, 9 deletions

diff --git a/src/layout/text.rs b/src/layout/text.rs
index 6aa5ef71..c1f4e464 100644
--- a/src/layout/text.rs
+++ b/src/layout/text.rs
@@ -1,22 +1,26 @@
 //! Layouting of text into boxes.
 
+use toddle::query::{FontQuery, SharedFontLoader};
+use toddle::tables::{Header, CharMap, HorizontalMetrics};
+
 use crate::doc::LayoutAction;
-use crate::font::FontQuery;
 use crate::size::{Size, Size2D};
 use super::*;
 
 
 /// The context for text layouting.
-#[derive(Debug, Copy, Clone)]
+#[derive(Copy, Clone)]
 pub struct TextContext<'a, 'p> {
     /// Loads fonts matching queries.
-    pub loader: &'a FontLoader<'p>,
+    pub loader: &'a SharedFontLoader<'p>,
     /// Base style to set text with.
     pub style: &'a TextStyle,
 }
 
 /// Layout one piece of text without any breaks as one continous box.
 pub fn layout(text: &str, ctx: TextContext) -> LayoutResult<BoxLayout> {
+    let mut loader = ctx.loader.borrow_mut();
+
     let mut actions = Vec::new();
     let mut active_font = std::usize::MAX;
     let mut buffer = String::new();
@@ -25,14 +29,45 @@ pub fn layout(text: &str, ctx: TextContext) -> LayoutResult<BoxLayout> {
     // Walk the characters.
     for character in text.chars() {
         // Retrieve the best font for this character.
-        let (index, font) = ctx.loader.get(FontQuery {
-            classes: ctx.style.classes.clone(),
-            fallback: ctx.style.fallback.clone(),
-            character,
-        }).ok_or_else(|| LayoutError::NoSuitableFont(character))?;
+        let mut font = None;
+        let mut classes = ctx.style.classes.clone();
+        for class in &ctx.style.fallback {
+            classes.push(class.clone());
+
+            font = loader.get(FontQuery {
+                chars: &[character],
+                classes: &classes,
+            });
+
+            if font.is_some() {
+                break;
+            }
+
+            classes.pop();
+        }
+
+        let (font, index) = match font {
+            Some(f) => f,
+            None => return Err(LayoutError::NoSuitableFont(character)),
+        };
+
+        // Create a conversion function between font units and sizes.
+        let font_unit_ratio = 1.0 / (font.read_table::<Header>()?.units_per_em as f32);
+        let font_unit_to_size = |x| Size::pt(font_unit_ratio * x);
 
         // Add the char width to the total box width.
-        let char_width = font.widths[font.encode(character) as usize] * ctx.style.font_size;
+        let glyph = font.read_table::<CharMap>()?
+            .get(character)
+            .expect("layout text: font should have char");
+
+        let glyph_width = font_unit_to_size(
+            font.read_table::<HorizontalMetrics>()?
+                .get(glyph)
+                .expect("layout text: font should have glyph")
+                .advance_width as f32
+        );
+
+        let char_width = glyph_width * ctx.style.font_size;
         width += char_width;
 
         // Change the font if necessary.