Text, many performance improvements

lib/ui/src/scene.rs

@@ -1,5 +1,6 @@
 //! Renderer-oriented scene snapshot types.
 
+use cosmic_text::CacheKey;
 use tracing::debug;
 
 use crate::trace_targets;
@@ -92,12 +93,16 @@ pub struct GlyphInstance {
     pub glyph: String,
     pub position: Point,
     pub advance: f32,
+    pub cache_key: Option<CacheKey>,
 }
 
 #[derive(Clone, Debug, PartialEq)]
 pub struct PreparedText {
     pub text: String,
+    pub origin: Point,
+    pub bounds: Option<UiSize>,
     pub font_size: f32,
+    pub line_height: f32,
     pub color: Color,
     pub glyphs: Vec<GlyphInstance>,
 }
@@ -118,13 +123,17 @@ impl PreparedText {
                 glyph: ch.to_string(),
                 position: Point::new(x, origin.y),
                 advance,
+                cache_key: None,
             });
             x += advance;
         }
 
         Self {
             text,
+            origin,
+            bounds: None,
             font_size,
+            line_height: font_size,
             color,
             glyphs,
         }