Split vvar and hvar

src/lib.rs

@@ -74,7 +74,7 @@ pub use tables::CFFError;
 #[cfg(feature = "apple-layout")]
 pub use tables::{ankr, feat, kerx, morx, trak};
 #[cfg(feature = "variable-fonts")]
-pub use tables::{avar, cff2, fvar, gvar, hvar, mvar};
+pub use tables::{avar, cff2, fvar, gvar, hvar, mvar, vvar};
 pub use tables::{cbdt, cblc, cff1 as cff, vhea};
 pub use tables::{
     cmap, colr, cpal, glyf, head, hhea, hmtx, kern, loca, maxp, name, os2, post, sbix, svg, vorg,
@@ -991,7 +991,7 @@ pub struct FaceTables<'a> {
     #[cfg(feature = "variable-fonts")]
     pub mvar: Option<mvar::Table<'a>>,
     #[cfg(feature = "variable-fonts")]
-    pub vvar: Option<hvar::Table<'a>>,
+    pub vvar: Option<vvar::Table<'a>>,
 }
 
 /// A font face.
@@ -1298,7 +1298,7 @@ impl<'a> Face<'a> {
             #[cfg(feature = "variable-fonts")]
             mvar: raw_tables.mvar.and_then(mvar::Table::parse),
             #[cfg(feature = "variable-fonts")]
-            vvar: raw_tables.vvar.and_then(hvar::Table::parse),
+            vvar: raw_tables.vvar.and_then(vvar::Table::parse),
         })
     }
 
@@ -1914,7 +1914,7 @@ impl<'a> Face<'a> {
             if self.is_variable() {
                 // Ignore variation offset when `hvar` is not set.
                 if let Some(hvar) = self.tables.hvar {
-                    if let Some(offset) = hvar.side_bearing_offset(glyph_id, self.coords()) {
+                    if let Some(offset) = hvar.left_side_bearing_offset(glyph_id, self.coords()) {
                         // We can't use `round()` in `no_std`, so this is the next best thing.
                         bearing += offset + 0.5;
                     }
@@ -1942,7 +1942,7 @@ impl<'a> Face<'a> {
             if self.is_variable() {
                 // Ignore variation offset when `vvar` is not set.
                 if let Some(vvar) = self.tables.vvar {
-                    if let Some(offset) = vvar.side_bearing_offset(glyph_id, self.coords()) {
+                    if let Some(offset) = vvar.top_side_bearing_offset(glyph_id, self.coords()) {
                         // We can't use `round()` in `no_std`, so this is the next best thing.
                         bearing += offset + 0.5;
                     }
@@ -1960,8 +1960,30 @@ impl<'a> Face<'a> {
 
     /// Returns glyph's vertical origin according to
     /// [Vertical Origin Table](https://docs.microsoft.com/en-us/typography/opentype/spec/vorg).
+    ///
+    /// This method is affected by variation axes.
     pub fn glyph_y_origin(&self, glyph_id: GlyphId) -> Option<i16> {
-        self.tables.vorg.map(|vorg| vorg.glyph_y_origin(glyph_id))
+        #[cfg(feature = "variable-fonts")]
+        {
+            let mut origin = self.tables.vorg.map(|vorg| vorg.glyph_y_origin(glyph_id))? as f32;
+
+            if self.is_variable() {
+                // Ignore variation offset when `vvar` is not set.
+                if let Some(vvar) = self.tables.vvar {
+                    if let Some(offset) = vvar.vertical_origin_offset(glyph_id, self.coords()) {
+                        // We can't use `round()` in `no_std`, so this is the next best thing.
+                        origin += offset + 0.5;
+                    }
+                }
+            }
+
+            i16::try_num_from(origin)
+        }
+
+        #[cfg(not(feature = "variable-fonts"))]
+        {
+            self.tables.vorg.map(|vorg| vorg.glyph_y_origin(glyph_id))
+        }
     }
 
     /// Returns glyph's name.

src/tables/hvar.rs

@@ -1,19 +1,20 @@
-//! A [Horizontal/Vertical Metrics Variations Table](
+//! A [Horizontal Metrics Variations Table](
 //! https://docs.microsoft.com/en-us/typography/opentype/spec/hvar) implementation.
 
 use crate::delta_set::DeltaSetIndexMap;
 use crate::parser::{Offset, Offset32, Stream};
 use crate::var_store::ItemVariationStore;
 use crate::{GlyphId, NormalizedCoordinate};
 
-/// A [Horizontal/Vertical Metrics Variations Table](
+/// A [Horizontal Metrics Variations Table](
 /// https://docs.microsoft.com/en-us/typography/opentype/spec/hvar).
 #[derive(Clone, Copy)]
 pub struct Table<'a> {
     data: &'a [u8],
     variation_store: ItemVariationStore<'a>,
     advance_width_mapping_offset: Option<Offset32>,
     lsb_mapping_offset: Option<Offset32>,
+    rsb_mapping_offset: Option<Offset32>,
 }
 
 impl<'a> Table<'a> {
@@ -35,10 +36,11 @@ impl<'a> Table<'a> {
             variation_store,
             advance_width_mapping_offset: s.read::<Option<Offset32>>()?,
             lsb_mapping_offset: s.read::<Option<Offset32>>()?,
+            rsb_mapping_offset: s.read::<Option<Offset32>>()?,
         })
     }
 
-    /// Returns advance offset for a glyph.
+    /// Returns the advance width offset for a glyph.
     #[inline]
     pub fn advance_offset(
         &self,
@@ -59,14 +61,34 @@ impl<'a> Table<'a> {
             .parse_delta(outer_idx, inner_idx, coordinates)
     }
 
-    /// Returns side bearing offset for a glyph.
+    /// Returns the left side bearing offset for a glyph.
     #[inline]
-    pub fn side_bearing_offset(
+    pub fn left_side_bearing_offset(
         &self,
         glyph_id: GlyphId,
         coordinates: &[NormalizedCoordinate],
     ) -> Option<f32> {
         let set_data = self.data.get(self.lsb_mapping_offset?.to_usize()..)?;
+        self.side_bearing_offset(glyph_id, coordinates, set_data)
+    }
+
+    /// Returns the right side bearing offset for a glyph.
+    #[inline]
+    pub fn right_side_bearing_offset(
+        &self,
+        glyph_id: GlyphId,
+        coordinates: &[NormalizedCoordinate],
+    ) -> Option<f32> {
+        let set_data = self.data.get(self.rsb_mapping_offset?.to_usize()..)?;
+        self.side_bearing_offset(glyph_id, coordinates, set_data)
+    }
+
+    fn side_bearing_offset(
+        &self,
+        glyph_id: GlyphId,
+        coordinates: &[NormalizedCoordinate],
+        set_data: &[u8],
+    ) -> Option<f32> {
         let (outer_idx, inner_idx) = DeltaSetIndexMap::new(set_data).map(glyph_id.0 as u32)?;
         self.variation_store
             .parse_delta(outer_idx, inner_idx, coordinates)

src/tables/mod.rs

@@ -49,6 +49,8 @@ pub mod gvar;
 pub mod hvar;
 #[cfg(feature = "variable-fonts")]
 pub mod mvar;
+#[cfg(feature = "variable-fonts")]
+pub mod vvar;
 
 pub use cff::cff1;
 #[cfg(feature = "variable-fonts")]

src/tables/vvar.rs

@@ -0,0 +1,115 @@
+//! A [Vertical Metrics Variations Table](
+//! https://docs.microsoft.com/en-us/typography/opentype/spec/hvar) implementation.
+
+use crate::delta_set::DeltaSetIndexMap;
+use crate::parser::{Offset, Offset32, Stream};
+use crate::var_store::ItemVariationStore;
+use crate::{GlyphId, NormalizedCoordinate};
+
+/// A [Vertical Metrics Variations Table](
+/// https://docs.microsoft.com/en-us/typography/opentype/spec/hvar).
+#[derive(Clone, Copy)]
+pub struct Table<'a> {
+    data: &'a [u8],
+    variation_store: ItemVariationStore<'a>,
+    advance_height_mapping_offset: Option<Offset32>,
+    tsb_mapping_offset: Option<Offset32>,
+    bsb_mapping_offset: Option<Offset32>,
+    vorg_mapping_offset: Option<Offset32>,
+}
+
+impl<'a> Table<'a> {
+    /// Parses a table from raw data.
+    pub fn parse(data: &'a [u8]) -> Option<Self> {
+        let mut s = Stream::new(data);
+
+        let version = s.read::<u32>()?;
+        if version != 0x00010000 {
+            return None;
+        }
+
+        let variation_store_offset = s.read::<Offset32>()?;
+        let var_store_s = Stream::new_at(data, variation_store_offset.to_usize())?;
+        let variation_store = ItemVariationStore::parse(var_store_s)?;
+
+        Some(Table {
+            data,
+            variation_store,
+            advance_height_mapping_offset: s.read::<Option<Offset32>>()?,
+            tsb_mapping_offset: s.read::<Option<Offset32>>()?,
+            bsb_mapping_offset: s.read::<Option<Offset32>>()?,
+            vorg_mapping_offset: s.read::<Option<Offset32>>()?,
+        })
+    }
+
+    /// Returns the advance height offset for a glyph.
+    #[inline]
+    pub fn advance_offset(
+        &self,
+        glyph_id: GlyphId,
+        coordinates: &[NormalizedCoordinate],
+    ) -> Option<f32> {
+        let (outer_idx, inner_idx) = if let Some(offset) = self.advance_height_mapping_offset {
+            DeltaSetIndexMap::new(self.data.get(offset.to_usize()..)?).map(glyph_id.0 as u32)?
+        } else {
+            // 'If there is no delta-set index mapping table for advance widths,
+            // then glyph IDs implicitly provide the indices:
+            // for a given glyph ID, the delta-set outer-level index is zero,
+            // and the glyph ID is the delta-set inner-level index.'
+            (0, glyph_id.0)
+        };
+
+        self.variation_store
+            .parse_delta(outer_idx, inner_idx, coordinates)
+    }
+
+    /// Returns the top side bearing offset for a glyph.
+    #[inline]
+    pub fn top_side_bearing_offset(
+        &self,
+        glyph_id: GlyphId,
+        coordinates: &[NormalizedCoordinate],
+    ) -> Option<f32> {
+        let set_data = self.data.get(self.tsb_mapping_offset?.to_usize()..)?;
+        self.side_bearing_offset(glyph_id, coordinates, set_data)
+    }
+
+    /// Returns the bottom side bearing offset for a glyph.
+    #[inline]
+    pub fn bottom_side_bearing_offset(
+        &self,
+        glyph_id: GlyphId,
+        coordinates: &[NormalizedCoordinate],
+    ) -> Option<f32> {
+        let set_data = self.data.get(self.bsb_mapping_offset?.to_usize()..)?;
+        self.side_bearing_offset(glyph_id, coordinates, set_data)
+    }
+
+    /// Returns the vertical origin offset for a glyph.
+    #[inline]
+    pub fn vertical_origin_offset(
+        &self,
+        glyph_id: GlyphId,
+        coordinates: &[NormalizedCoordinate],
+    ) -> Option<f32> {
+        let set_data = self.data.get(self.vorg_mapping_offset?.to_usize()..)?;
+        self.side_bearing_offset(glyph_id, coordinates, set_data)
+    }
+
+    fn side_bearing_offset(
+        &self,
+        glyph_id: GlyphId,
+        coordinates: &[NormalizedCoordinate],
+        set_data: &[u8],
+    ) -> Option<f32> {
+        let (outer_idx, inner_idx) = DeltaSetIndexMap::new(set_data).map(glyph_id.0 as u32)?;
+        self.variation_store
+            .parse_delta(outer_idx, inner_idx, coordinates)
+    }
+}
+
+impl core::fmt::Debug for Table<'_> {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        write!(f, "Table {{ ... }}")
+    }
+}