more progress, but can't use text blob creation utilities :/

src/renderer/caching_shaper.rs

@@ -1,42 +1,100 @@
 use lru::LruCache;
-use skulpin::skia_safe::{Shaper, TextBlob, Font, Point};
+use skulpin::skia_safe::{Shaper, TextBlob, Font, Point, TextBlobBuilder};
+use font_kit::source::SystemSource;
+use skribo::{
+    layout, layout_run, make_layout, FontCollection, FontFamily, FontRef, Layout, LayoutSession,
+    TextStyle
+};
 
 #[derive(new, Clone, Hash, PartialEq, Eq)]
-struct ShapeKey {
-    pub text: String,
+struct FontKey {
+    pub name: String,
     pub scale: u16,
     pub bold: bool,
     pub italic: bool
 }
 
+#[derive(new, Clone, Hash, PartialEq, Eq)]
+struct ShapeKey {
+    pub text: String,
+    pub font_key: FontKey
+}
+
 pub struct CachingShaper {
-    shaper: Shaper,
-    cache: LruCache<ShapeKey, TextBlob>
+    font_cache: LruCache<FontKey, FontRef>,
+    blob_cache: LruCache<ShapeKey, TextBlob>
 }
 
 impl CachingShaper {
     pub fn new() -> CachingShaper {
         CachingShaper {
-            shaper: Shaper::new(None),
-            cache: LruCache::new(10000)
+            font_cache: LruCache::new(100),
+            blob_cache: LruCache::new(10000)
         }
     }
 
-    pub fn shape(&self, text: &str, font: &Font) -> TextBlob {
-        let (blob, _) = self.shaper.shape_text_blob(text, font, true, 1000000.0, Point::default()).unwrap();
-        blob
+    fn get_font(&self, font_key: &FontKey) -> &FontRef {
+        if !self.font_cache.contains(font_key) {
+            let source = SystemSource::new();
+            let font_name = font_key.name.clone();
+            let font = source
+                .select_family_by_name(&font_name)
+                .expect("Failed to load by postscript name")
+                .fonts()[0]
+                .load()
+                .unwrap();
+            self.font_cache.put(key.clone(), FontRef::new(font));
+        }
+
+        self.font_cache.get(&key).unwrap()
+    }
+
+    pub fn shape(&self, text: &str, font_name: &str, scale: u16, bold: bool, italic: bool, font: &Font) -> TextBlob {
+        let font_key = FontKey::new(font_name.to_string(), scale, bold, italic);
+        let font_ref = self.get_font(&font_key);
+
+        let style = TextStyle { size: font_size };
+        let layout = layout_run(&style, &font_ref, standard_character_string);
+
+        let blob_builder = TextBlobBuilder::new();
+
+        unsafe {
+            let count = layout.glyphs.count();
+            let buffer = blob_builder
+                .native_mut()
+                .allocRunPosH(font.native(), count.try_into().unwrap(), 0, None);
+            let mut glyphs = slice::from_raw_parts_mut((*buffer).glyphs, count);
+            for (glyph_id, i) in layout.glyphs.iter().map(|glyph| glyph.glyph_id as u16).enumerate() {
+                glyphs[i] = glyph_id;
+            }
+            let mut positions = slice::from_raw_parts_mut((*buffer).pos, count);
+            for (offset, i) in layout.glyphs.iter().map(|glyph| glyph.offset.x as f32).enumerate() {
+                positions[i] = offset;
+            }
+        }
+
+        blob_builder.make()
+        // TextBlob::from_pos_text_h(text.as_bytes(), layout.glyphs.iter().
+        // let (mut glyphs, mut points) = blob_builder.alloc_run_pos(
+        // // let glyph_offsets: Vec<f32> = layout.glyphs.iter().map(|glyph| glyph.offset.x).collect();
+        // // let glyph_advances: Vec<f32> = glyph_offsets.windows(2).map(|pair| pair[1] - pair[0]).collect();
+
+        // let (blob, _) = self.shaper.shape_text_blob(text, font, true, 1000000.0, Point::default()).unwrap();
+        // blob
     }
 
-    pub fn shape_cached(&mut self, text: String, scale: u16, bold: bool, italic: bool, font: &Font) -> &TextBlob {
-        let key = ShapeKey::new(text.clone(), scale, bold, italic);
-        if !self.cache.contains(&key) {
-            self.cache.put(key.clone(), self.shape(&text, &font));
+    pub fn shape_cached(&mut self, text: &str, font_name: &str, scale: u16, bold: bool, italic: bool, font: &Font) -> &TextBlob {
+        let font_key = FontKey::new(font_name.to_string(), scale, bold, italic);
+        let key = ShapeKey::new(text.to_string(), font_key);
+        if !self.blob_cache.contains(&key) {
+            self.blob_cache.put(key.clone(), self.shape(text, font_name, scale, bold, italic, &font));
         }
 
-        self.cache.get(&key).unwrap()
+        self.blob_cache.get(&key).unwrap()
     }
 
     pub fn clear(&mut self) {
-        self.cache.clear();
+        self.font_cache.clear();
+        self.blob_cache.clear();
     }
 }

src/renderer/fonts.rs

@@ -7,7 +7,7 @@ use skribo::{
 };
 use crate::editor::Style;
 
-const standard_character_string: &'static str = "XXXX";
+const standard_character_string: &'static str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
 
 pub struct Fonts {
     pub name: String,
@@ -106,11 +106,17 @@ impl FontLookup {
         let font_ref = FontRef::new(font);
         let style = TextStyle { size: font_size };
         let layout = layout_run(&style, &font_ref, standard_character_string);
-        let font_width = layout.advance.x / standard_character_string.len() as f32;
-        // let glyph_offsets: Vec<f32> = layout.glyphs.iter().map(|glyph| glyph.offset.x).collect();
-        // let glyph_advances: Vec<f32> = glyph_offsets.windows(2).map(|pair| pair[1] - pair[0]).collect();
-        // dbg!(&glyph_advances);
-        // let font_width = glyph_advances.iter().cloned().fold(0.0, f32::max);
+        let glyph_offsets: Vec<f32> = layout.glyphs.iter().map(|glyph| glyph.offset.x).collect();
+        let glyph_advances: Vec<f32> = glyph_offsets.windows(2).map(|pair| pair[1] - pair[0]).collect();
+
+        let mut amounts = HashMap::new();
+        for advance in glyph_advances.iter() {
+            amounts.entry(advance.to_string())
+                .and_modify(|e| *e += 1)
+                .or_insert(1);
+        }
+        let (font_width, _) = amounts.into_iter().max_by_key(|(_, count)| count.clone()).unwrap();
+        let font_width = font_width.parse::<f32>().unwrap();
 
         (font_width, font_height)
     }