Generate write-fonts' MVAR modules

a step towards googlefonts/fontc#531

resources/codegen_plan.toml

@@ -83,6 +83,11 @@ mode = "parse"
 source = "resources/codegen_inputs/mvar.rs"
 target = "read-fonts/generated/generated_mvar.rs"
 
+[[generate]]
+mode = "compile"
+source = "resources/codegen_inputs/mvar.rs"
+target = "write-fonts/generated/generated_mvar.rs"
+
 [[generate]]
 mode = "parse"
 source = "resources/codegen_inputs/layout.rs"

write-fonts/generated/generated_mvar.rs

@@ -0,0 +1,146 @@
+// THIS FILE IS AUTOGENERATED.
+// Any changes to this file will be overwritten.
+// For more information about how codegen works, see font-codegen/README.md
+
+#[allow(unused_imports)]
+use crate::codegen_prelude::*;
+
+/// The [MVAR (Metrics Variations)](https://docs.microsoft.com/en-us/typography/opentype/spec/mvar) table
+#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Mvar {
+    /// Major version number of the horizontal metrics variations table — set to 1.
+    /// Minor version number of the horizontal metrics variations table — set to 0.
+    pub version: MajorMinor,
+    /// The size in bytes of each value record — must be greater than zero.
+    pub value_record_size: u16,
+    /// The number of value records — may be zero.
+    pub value_record_count: u16,
+    /// Offset in bytes from the start of this table to the item variation store table. If valueRecordCount is zero, set to zero; if valueRecordCount is greater than zero, must be greater than zero.
+    pub item_variation_store: NullableOffsetMarker<ItemVariationStore, WIDTH_32>,
+    /// Array of value records that identify target items and the associated delta-set index for each. The valueTag records must be in binary order of their valueTag field.
+    pub value_records: Vec<ValueRecord>,
+}
+
+impl Mvar {
+    /// Construct a new `Mvar`
+    pub fn new(
+        version: MajorMinor,
+        value_record_size: u16,
+        value_record_count: u16,
+        item_variation_store: Option<ItemVariationStore>,
+        value_records: Vec<ValueRecord>,
+    ) -> Self {
+        Self {
+            version,
+            value_record_size,
+            value_record_count,
+            item_variation_store: item_variation_store.into(),
+            value_records: value_records.into_iter().map(Into::into).collect(),
+        }
+    }
+}
+
+impl FontWrite for Mvar {
+    #[allow(clippy::unnecessary_cast)]
+    fn write_into(&self, writer: &mut TableWriter) {
+        self.version.write_into(writer);
+        (0 as u16).write_into(writer);
+        self.value_record_size.write_into(writer);
+        self.value_record_count.write_into(writer);
+        self.item_variation_store.write_into(writer);
+        self.value_records.write_into(writer);
+    }
+    fn table_type(&self) -> TableType {
+        TableType::TopLevel(Mvar::TAG)
+    }
+}
+
+impl Validate for Mvar {
+    fn validate_impl(&self, ctx: &mut ValidationCtx) {
+        ctx.in_table("Mvar", |ctx| {
+            ctx.in_field("item_variation_store", |ctx| {
+                self.item_variation_store.validate_impl(ctx);
+            });
+            ctx.in_field("value_records", |ctx| {
+                if self.value_records.len() > (u16::MAX as usize) {
+                    ctx.report("array exceeds max length");
+                }
+                self.value_records.validate_impl(ctx);
+            });
+        })
+    }
+}
+
+impl TopLevelTable for Mvar {
+    const TAG: Tag = Tag::new(b"MVAR");
+}
+
+impl<'a> FromObjRef<read_fonts::tables::mvar::Mvar<'a>> for Mvar {
+    fn from_obj_ref(obj: &read_fonts::tables::mvar::Mvar<'a>, _: FontData) -> Self {
+        let offset_data = obj.offset_data();
+        Mvar {
+            version: obj.version(),
+            value_record_size: obj.value_record_size(),
+            value_record_count: obj.value_record_count(),
+            item_variation_store: obj.item_variation_store().to_owned_table(),
+            value_records: obj.value_records().to_owned_obj(offset_data),
+        }
+    }
+}
+
+impl<'a> FromTableRef<read_fonts::tables::mvar::Mvar<'a>> for Mvar {}
+
+impl<'a> FontRead<'a> for Mvar {
+    fn read(data: FontData<'a>) -> Result<Self, ReadError> {
+        <read_fonts::tables::mvar::Mvar as FontRead>::read(data).map(|x| x.to_owned_table())
+    }
+}
+
+/// [ValueRecord](https://learn.microsoft.com/en-us/typography/opentype/spec/mvar#table-formats) metrics variation record
+#[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct ValueRecord {
+    /// Four-byte tag identifying a font-wide measure.
+    pub value_tag: Tag,
+    /// A delta-set outer index — used to select an item variation data subtable within the item variation store.
+    pub delta_set_outer_index: u16,
+    /// A delta-set inner index — used to select a delta-set row within an item variation data subtable.
+    pub delta_set_inner_index: u16,
+}
+
+impl ValueRecord {
+    /// Construct a new `ValueRecord`
+    pub fn new(value_tag: Tag, delta_set_outer_index: u16, delta_set_inner_index: u16) -> Self {
+        Self {
+            value_tag,
+            delta_set_outer_index,
+            delta_set_inner_index,
+        }
+    }
+}
+
+impl FontWrite for ValueRecord {
+    fn write_into(&self, writer: &mut TableWriter) {
+        self.value_tag.write_into(writer);
+        self.delta_set_outer_index.write_into(writer);
+        self.delta_set_inner_index.write_into(writer);
+    }
+    fn table_type(&self) -> TableType {
+        TableType::Named("ValueRecord")
+    }
+}
+
+impl Validate for ValueRecord {
+    fn validate_impl(&self, _ctx: &mut ValidationCtx) {}
+}
+
+impl FromObjRef<read_fonts::tables::mvar::ValueRecord> for ValueRecord {
+    fn from_obj_ref(obj: &read_fonts::tables::mvar::ValueRecord, _: FontData) -> Self {
+        ValueRecord {
+            value_tag: obj.value_tag(),
+            delta_set_outer_index: obj.delta_set_outer_index(),
+            delta_set_inner_index: obj.delta_set_inner_index(),
+        }
+    }
+}

write-fonts/src/tables/mvar.rs

@@ -0,0 +1,3 @@
+//! The [MVAR](https://learn.microsoft.com/en-us/typography/opentype/spec/mvar) table
+
+include!("../../generated/generated_mvar.rs");