[chore] Update write-fonts to 0.21.0

This involves a breaking change to the VariationStoreBuilder, which in
turn requires us to tweak the FeatureProvider trait in fea-rs, but
overall fairly painless.

Cargo.toml

@@ -20,8 +20,8 @@ clap = { version = "4.0.32", features = ["derive"] }
 rayon = "1.6"
 
 # fontations etc
-write-fonts = { version = "0.19.0", features = ["serde", "read"] }
-skrifa = "0.14.0"
+write-fonts = { version = "0.21.0", features = ["serde", "read"] }
+skrifa = "0.15.0"
 norad = "0.12"
 
 # dev dependencies

fea-rs/src/compile/compile_ctx.rs

@@ -184,7 +184,11 @@ impl<'a, F: FeatureProvider, V: VariationInfo> CompilationCtx<'a, F, V> {
 
         // the var store builder is required so that variable metrics/anchors
         // in the GPOS table can be collected into an ItemVariationStore
-        let mut ivs = VariationStoreBuilder::new();
+        let axis_count = self
+            .variation_info
+            .map(|info| info.axis_count())
+            .unwrap_or_default();
+        let mut ivs = VariationStoreBuilder::new(axis_count);
 
         let (mut gsub, mut gpos) = self.lookups.build(&self.features, &mut ivs);
         if !ivs.is_empty() {

fea-rs/src/compile/variations.rs

@@ -22,6 +22,9 @@ pub trait VariationInfo {
     /// The error type
     type Error: std::error::Error;
 
+    /// The number of axes in the fvar table
+    fn axis_count(&self) -> u16;
+
     /// If the tag is an axis in this font, it's fvar index and it's [`Axis`] data.
     fn axis(&self, axis_tag: Tag) -> Option<(usize, &Axis)>;
 
@@ -52,6 +55,10 @@ pub struct NopVariationInfo;
 impl VariationInfo for NopVariationInfo {
     type Error = NopError;
 
+    fn axis_count(&self) -> u16 {
+        0
+    }
+
     fn axis(&self, _: Tag) -> Option<(usize, &Axis)> {
         None
     }
@@ -201,6 +208,10 @@ impl VariationInfo for MockVariationInfo {
     ) -> Result<(i16, Vec<(VariationRegion, i16)>), Self::Error> {
         Ok(Default::default())
     }
+
+    fn axis_count(&self) -> u16 {
+        self.axes.len().try_into().unwrap()
+    }
 }
 
 #[cfg(test)]

fontbe/src/features.rs

@@ -336,6 +336,10 @@ impl<'a> VariationInfo for FeaVariationInfo<'a> {
 
         Ok((default_value, fears_deltas))
     }
+
+    fn axis_count(&self) -> u16 {
+        self.axes.len().try_into().unwrap()
+    }
 }
 
 impl FeatureWork {

fontbe/src/hvar.rs

@@ -166,6 +166,7 @@ impl Work<Context, AnyWorkId, Error> for HvarWork {
         let static_metadata = context.ir.static_metadata.get();
         let var_model = &static_metadata.variation_model;
         let glyph_order = context.ir.glyph_order.get();
+        let axis_count = var_model.axes().count().try_into().unwrap();
 
         let mut glyph_width_deltas = AdvanceWidthDeltas::new(var_model.clone());
         for name in glyph_order.iter() {
@@ -177,7 +178,7 @@ impl Work<Context, AnyWorkId, Error> for HvarWork {
         // indices (a single ItemVariationData, outer index 0, inner index => gid).
         let mut var_idxes = Vec::new();
         let direct_store = if glyph_width_deltas.is_single_model() {
-            let mut direct_builder = VariationStoreBuilder::new_with_implicit_indices();
+            let mut direct_builder = VariationStoreBuilder::new_with_implicit_indices(axis_count);
             for deltas in glyph_width_deltas.iter() {
                 var_idxes.push(direct_builder.add_deltas(deltas.clone()));
             }
@@ -194,7 +195,7 @@ impl Work<Context, AnyWorkId, Error> for HvarWork {
         };
 
         // also build an indirect VariationStore with a DeltaSetIndexMap to map gid => varidx
-        let mut indirect_builder = VariationStoreBuilder::new();
+        let mut indirect_builder = VariationStoreBuilder::new(axis_count);
         for deltas in glyph_width_deltas.iter() {
             var_idxes.push(indirect_builder.add_deltas(deltas.clone()));
         }

layout-normalizer/src/gpos/pairpos.rs

@@ -233,7 +233,7 @@ mod tests {
         }
 
         fn build_exactly_one_subtable(self) -> PairPos {
-            let mut varstore = VariationStoreBuilder::new();
+            let mut varstore = VariationStoreBuilder::new(0);
             let subs = self.build(&mut varstore);
             assert_eq!(subs.len(), 1);
             subs.into_iter().next().unwrap()