Add strongly typed PaletteType flags to CPAL

JMM

font-codegen/src/parsing.rs

@@ -554,7 +554,11 @@ impl Parse for BitFlags {
         let docs = get_optional_docs(input)?;
         let _kw = input.parse::<kw::flags>()?;
         let typ = input.parse::<syn::Ident>()?;
-        validate_ident(&typ, &["u8", "u16"], "allowed bitflag types: u8, u16")?;
+        validate_ident(
+            &typ,
+            &["u8", "u16", "u32"],
+            "allowed bitflag types: u8, u16, u32",
+        )?;
         let name = input.parse::<syn::Ident>()?;
 
         let content;

read-fonts/generated/generated_cpal.rs

@@ -154,7 +154,7 @@ impl<'a> Cpal<'a> {
     }
 
     /// Attempt to resolve [`palette_types_array_offset`][Self::palette_types_array_offset].
-    pub fn palette_types_array(&self) -> Option<Result<&'a [BigEndian<u32>], ReadError>> {
+    pub fn palette_types_array(&self) -> Option<Result<&'a [BigEndian<PaletteType>], ReadError>> {
         let data = self.data;
         let args = self.num_palettes();
         self.palette_types_array_offset()
@@ -265,6 +265,319 @@ impl<'a> std::fmt::Debug for Cpal<'a> {
     }
 }
 
+/// The [PaletteType](https://learn.microsoft.com/en-us/typography/opentype/spec/cpal#palette-type-array) flags.
+#[derive(Clone, Copy, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct PaletteType {
+    bits: u32,
+}
+
+impl PaletteType {
+    /// Bit 0: palette is appropriate to use when displaying the font on a light background such as white.
+    pub const USABLE_WITH_LIGHT_BACKGROUND: Self = Self { bits: 0x0001 };
+
+    /// Bit 1: palette is appropriate to use when displaying the font on a dark background such as black.
+    pub const USABLE_WITH_DARK_BACKGROUND: Self = Self { bits: 0x0002 };
+}
+
+impl PaletteType {
+    ///  Returns an empty set of flags.
+    #[inline]
+    pub const fn empty() -> Self {
+        Self { bits: 0 }
+    }
+
+    /// Returns the set containing all flags.
+    #[inline]
+    pub const fn all() -> Self {
+        Self {
+            bits: Self::USABLE_WITH_LIGHT_BACKGROUND.bits | Self::USABLE_WITH_DARK_BACKGROUND.bits,
+        }
+    }
+
+    /// Returns the raw value of the flags currently stored.
+    #[inline]
+    pub const fn bits(&self) -> u32 {
+        self.bits
+    }
+
+    /// Convert from underlying bit representation, unless that
+    /// representation contains bits that do not correspond to a flag.
+    #[inline]
+    pub const fn from_bits(bits: u32) -> Option<Self> {
+        if (bits & !Self::all().bits()) == 0 {
+            Some(Self { bits })
+        } else {
+            None
+        }
+    }
+
+    /// Convert from underlying bit representation, dropping any bits
+    /// that do not correspond to flags.
+    #[inline]
+    pub const fn from_bits_truncate(bits: u32) -> Self {
+        Self {
+            bits: bits & Self::all().bits,
+        }
+    }
+
+    /// Returns `true` if no flags are currently stored.
+    #[inline]
+    pub const fn is_empty(&self) -> bool {
+        self.bits() == Self::empty().bits()
+    }
+
+    /// Returns `true` if there are flags common to both `self` and `other`.
+    #[inline]
+    pub const fn intersects(&self, other: Self) -> bool {
+        !(Self {
+            bits: self.bits & other.bits,
+        })
+        .is_empty()
+    }
+
+    /// Returns `true` if all of the flags in `other` are contained within `self`.
+    #[inline]
+    pub const fn contains(&self, other: Self) -> bool {
+        (self.bits & other.bits) == other.bits
+    }
+
+    /// Inserts the specified flags in-place.
+    #[inline]
+    pub fn insert(&mut self, other: Self) {
+        self.bits |= other.bits;
+    }
+
+    /// Removes the specified flags in-place.
+    #[inline]
+    pub fn remove(&mut self, other: Self) {
+        self.bits &= !other.bits;
+    }
+
+    /// Toggles the specified flags in-place.
+    #[inline]
+    pub fn toggle(&mut self, other: Self) {
+        self.bits ^= other.bits;
+    }
+
+    /// Returns the intersection between the flags in `self` and
+    /// `other`.
+    ///
+    /// Specifically, the returned set contains only the flags which are
+    /// present in *both* `self` *and* `other`.
+    ///
+    /// This is equivalent to using the `&` operator (e.g.
+    /// [`ops::BitAnd`]), as in `flags & other`.
+    ///
+    /// [`ops::BitAnd`]: https://doc.rust-lang.org/std/ops/trait.BitAnd.html
+    #[inline]
+    #[must_use]
+    pub const fn intersection(self, other: Self) -> Self {
+        Self {
+            bits: self.bits & other.bits,
+        }
+    }
+
+    /// Returns the union of between the flags in `self` and `other`.
+    ///
+    /// Specifically, the returned set contains all flags which are
+    /// present in *either* `self` *or* `other`, including any which are
+    /// present in both.
+    ///
+    /// This is equivalent to using the `|` operator (e.g.
+    /// [`ops::BitOr`]), as in `flags | other`.
+    ///
+    /// [`ops::BitOr`]: https://doc.rust-lang.org/std/ops/trait.BitOr.html
+    #[inline]
+    #[must_use]
+    pub const fn union(self, other: Self) -> Self {
+        Self {
+            bits: self.bits | other.bits,
+        }
+    }
+
+    /// Returns the difference between the flags in `self` and `other`.
+    ///
+    /// Specifically, the returned set contains all flags present in
+    /// `self`, except for the ones present in `other`.
+    ///
+    /// It is also conceptually equivalent to the "bit-clear" operation:
+    /// `flags & !other` (and this syntax is also supported).
+    ///
+    /// This is equivalent to using the `-` operator (e.g.
+    /// [`ops::Sub`]), as in `flags - other`.
+    ///
+    /// [`ops::Sub`]: https://doc.rust-lang.org/std/ops/trait.Sub.html
+    #[inline]
+    #[must_use]
+    pub const fn difference(self, other: Self) -> Self {
+        Self {
+            bits: self.bits & !other.bits,
+        }
+    }
+}
+
+impl std::ops::BitOr for PaletteType {
+    type Output = Self;
+
+    /// Returns the union of the two sets of flags.
+    #[inline]
+    fn bitor(self, other: PaletteType) -> Self {
+        Self {
+            bits: self.bits | other.bits,
+        }
+    }
+}
+
+impl std::ops::BitOrAssign for PaletteType {
+    /// Adds the set of flags.
+    #[inline]
+    fn bitor_assign(&mut self, other: Self) {
+        self.bits |= other.bits;
+    }
+}
+
+impl std::ops::BitXor for PaletteType {
+    type Output = Self;
+
+    /// Returns the left flags, but with all the right flags toggled.
+    #[inline]
+    fn bitxor(self, other: Self) -> Self {
+        Self {
+            bits: self.bits ^ other.bits,
+        }
+    }
+}
+
+impl std::ops::BitXorAssign for PaletteType {
+    /// Toggles the set of flags.
+    #[inline]
+    fn bitxor_assign(&mut self, other: Self) {
+        self.bits ^= other.bits;
+    }
+}
+
+impl std::ops::BitAnd for PaletteType {
+    type Output = Self;
+
+    /// Returns the intersection between the two sets of flags.
+    #[inline]
+    fn bitand(self, other: Self) -> Self {
+        Self {
+            bits: self.bits & other.bits,
+        }
+    }
+}
+
+impl std::ops::BitAndAssign for PaletteType {
+    /// Disables all flags disabled in the set.
+    #[inline]
+    fn bitand_assign(&mut self, other: Self) {
+        self.bits &= other.bits;
+    }
+}
+
+impl std::ops::Sub for PaletteType {
+    type Output = Self;
+
+    /// Returns the set difference of the two sets of flags.
+    #[inline]
+    fn sub(self, other: Self) -> Self {
+        Self {
+            bits: self.bits & !other.bits,
+        }
+    }
+}
+
+impl std::ops::SubAssign for PaletteType {
+    /// Disables all flags enabled in the set.
+    #[inline]
+    fn sub_assign(&mut self, other: Self) {
+        self.bits &= !other.bits;
+    }
+}
+
+impl std::ops::Not for PaletteType {
+    type Output = Self;
+
+    /// Returns the complement of this set of flags.
+    #[inline]
+    fn not(self) -> Self {
+        Self { bits: !self.bits } & Self::all()
+    }
+}
+
+impl std::fmt::Debug for PaletteType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        let members: &[(&str, Self)] = &[
+            (
+                "USABLE_WITH_LIGHT_BACKGROUND",
+                Self::USABLE_WITH_LIGHT_BACKGROUND,
+            ),
+            (
+                "USABLE_WITH_DARK_BACKGROUND",
+                Self::USABLE_WITH_DARK_BACKGROUND,
+            ),
+        ];
+        let mut first = true;
+        for (name, value) in members {
+            if self.contains(*value) {
+                if !first {
+                    f.write_str(" | ")?;
+                }
+                first = false;
+                f.write_str(name)?;
+            }
+        }
+        if first {
+            f.write_str("(empty)")?;
+        }
+        Ok(())
+    }
+}
+
+impl std::fmt::Binary for PaletteType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Binary::fmt(&self.bits, f)
+    }
+}
+
+impl std::fmt::Octal for PaletteType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::Octal::fmt(&self.bits, f)
+    }
+}
+
+impl std::fmt::LowerHex for PaletteType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::LowerHex::fmt(&self.bits, f)
+    }
+}
+
+impl std::fmt::UpperHex for PaletteType {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        std::fmt::UpperHex::fmt(&self.bits, f)
+    }
+}
+
+impl font_types::Scalar for PaletteType {
+    type Raw = <u32 as font_types::Scalar>::Raw;
+    fn to_raw(self) -> Self::Raw {
+        self.bits().to_raw()
+    }
+    fn from_raw(raw: Self::Raw) -> Self {
+        let t = <u32>::from_raw(raw);
+        Self::from_bits_truncate(t)
+    }
+}
+
+#[cfg(feature = "traversal")]
+impl<'a> From<PaletteType> for FieldType<'a> {
+    fn from(src: PaletteType) -> FieldType<'a> {
+        src.bits().into()
+    }
+}
+
 /// [CPAL (Color Record)](https://learn.microsoft.com/en-us/typography/opentype/spec/cpal#palette-entries-and-color-records) record
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[repr(C)]

resources/codegen_inputs/cpal.rs

@@ -31,7 +31,7 @@ table Cpal {
     #[since_version(1)]
     #[nullable]
     #[read_offset_with($num_palettes)]
-    palette_types_array_offset: Offset32<[u32]>,
+    palette_types_array_offset: Offset32<[PaletteType]>,
     /// Offset from the beginning of CPAL table to the [Palette Labels Array][].
     ///
     /// This is an array of 'name' table IDs (typically in the font-specific name
@@ -58,6 +58,14 @@ table Cpal {
     palette_entry_labels_array_offset: Offset32<[NameId]>,
 }
 
+/// The [PaletteType](https://learn.microsoft.com/en-us/typography/opentype/spec/cpal#palette-type-array) flags.
+flags u32 PaletteType {
+    /// Bit 0: palette is appropriate to use when displaying the font on a light background such as white.
+    USABLE_WITH_LIGHT_BACKGROUND = 0x0001,
+    /// Bit 1: palette is appropriate to use when displaying the font on a dark background such as black.
+    USABLE_WITH_DARK_BACKGROUND = 0x0002,
+}
+
 /// [CPAL (Color Record)](https://learn.microsoft.com/en-us/typography/opentype/spec/cpal#palette-entries-and-color-records) record
 record ColorRecord {
     /// Blue value (B0).

write-fonts/generated/generated_cpal.rs

@@ -5,6 +5,8 @@
 #[allow(unused_imports)]
 use crate::codegen_prelude::*;
 
+pub use read_fonts::tables::cpal::PaletteType;
+
 /// [CPAL (Color Palette Table)](https://learn.microsoft.com/en-us/typography/opentype/spec/cpal#palette-table-header) table
 #[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
@@ -26,7 +28,7 @@ pub struct Cpal {
     /// This is an array of 32-bit flag fields that describe properties of each palette.
     ///
     /// [Palette Types Array]: https://learn.microsoft.com/en-us/typography/opentype/spec/cpal#palette-type-array
-    pub palette_types_array: NullableOffsetMarker<Vec<u32>, WIDTH_32>,
+    pub palette_types_array: NullableOffsetMarker<Vec<PaletteType>, WIDTH_32>,
     /// Offset from the beginning of CPAL table to the [Palette Labels Array][].
     ///
     /// This is an array of 'name' table IDs (typically in the font-specific name
@@ -135,6 +137,12 @@ impl<'a> FontRead<'a> for Cpal {
     }
 }
 
+impl FontWrite for PaletteType {
+    fn write_into(&self, writer: &mut TableWriter) {
+        writer.write_slice(&self.bits().to_be_bytes())
+    }
+}
+
 /// [CPAL (Color Record)](https://learn.microsoft.com/en-us/typography/opentype/spec/cpal#palette-entries-and-color-records) record
 #[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]