Text, morph: share a run's gradient between glyph runs, match morph tokens by text

crates/render/src/morph_text.rs

@@ -76,16 +76,12 @@ fn tokens(l: &TextLayout, chars: bool) -> (Vec<Token>, Vec<(usize, usize)>) {
 
 /// For each token of `b`, the token of `a` with the same text, in reading order, each used once.
 fn matches(a: &[Token], b: &[Token]) -> Vec<Option<usize>> {
-    let mut used = vec![false; a.len()];
-    b.iter()
-        .map(|tb| {
-            let i = a.iter().enumerate().position(|(i, ta)| !used.get(i).copied().unwrap_or(true) && ta.key == tb.key)?;
-            if let Some(u) = used.get_mut(i) {
-                *u = true;
-            }
-            Some(i)
-        })
-        .collect()
+    // Unused tokens of `a` by text, in reading order, so each lookup is a pop rather than a scan.
+    let mut free: std::collections::HashMap<&str, std::collections::VecDeque<usize>> = std::collections::HashMap::new();
+    for (i, ta) in a.iter().enumerate() {
+        free.entry(ta.key.as_str()).or_default().push_back(i);
+    }
+    b.iter().map(|tb| free.get_mut(tb.key.as_str())?.pop_front()).collect()
 }
 
 fn layout(ctx: &Ctx, s: &Shape, x: Xfrm, fields: &dyn Fields) -> Option<TextLayout> {
@@ -228,3 +224,19 @@ pub(crate) fn draw(
 pub(crate) fn token_keys(l: &TextLayout, chars: bool) -> Vec<String> {
     tokens(l, chars).0.into_iter().map(|t| t.key).collect()
 }
+
+#[cfg(test)]
+mod match_tests {
+    use super::*;
+
+    fn tok(k: &str) -> Token {
+        Token { key: k.into(), glyphs: Vec::new(), origin: Point::ZERO, run: 0 }
+    }
+
+    #[test]
+    fn each_source_token_is_used_once_in_reading_order() {
+        let a: Vec<Token> = ["a", "b", "a"].map(tok).into();
+        let b: Vec<Token> = ["a", "a", "a", "b", "c"].map(tok).into();
+        assert_eq!(matches(&a, &b), vec![Some(0), Some(2), None, Some(1), None]);
+    }
+}

crates/text/src/run.rs

@@ -22,7 +22,7 @@ pub struct GlyphRun {
     pub link: bool,
     /// Opacity of the fill on top of `color`'s own alpha (0 for no fill).
     pub alpha: f64,
-    pub gradient: Option<deckcraft_model::style::Gradient>,
+    pub gradient: Option<std::sync::Arc<deckcraft_model::style::Gradient>>,
     /// Shadow and glow behind the glyphs (`a:rPr/a:effectLst`).
     pub effects: Option<RunEffects>,
     /// East Asian vertical text (`eaVert`): each glyph stands upright, turned a quarter turn

crates/text/src/style.rs

@@ -46,7 +46,7 @@ pub(crate) struct Style {
     pub(crate) highlight: Option<Rgba>,
     pub(crate) outline: Option<(Rgba, f64)>,
     pub(crate) link: bool,
-    pub(crate) gradient: Option<deckcraft_model::style::Gradient>,
+    pub(crate) gradient: Option<std::sync::Arc<deckcraft_model::style::Gradient>>,
     pub(crate) effects: Option<RunEffects>,
     /// "Regular", "Bold"… for the slot and fallback faces.
     pub(crate) style_name: &'static str,
@@ -136,7 +136,7 @@ pub(crate) fn make_style(ctx: &Ctx, r: &RunProps, scale: f64, prompt: Option<Rgb
             for s in &mut g.stops {
                 s.color = deckcraft_model::ColorRef::rgb(ctx.color(&s.color, None));
             }
-            (g.stops.first().map(|s| ctx.color(&s.color, None)).unwrap_or(Rgba::BLACK), 1.0, Some(g))
+            (g.stops.first().map(|s| ctx.color(&s.color, None)).unwrap_or(Rgba::BLACK), 1.0, Some(std::sync::Arc::new(g)))
         }
         Some(Fill::None) => (Rgba::TRANSPARENT, 0.0, None),
         _ => (resolve::text_color(ctx, r), 1.0, None),