[skrifa] hinting mode changes/remove feature gate (#710)

- removes the hinting feature gate
- adds a `None` variant to `Hinting` enum to use as a replacement for `Option<Hinting>` so call sites taking this as a parameter have greater clarity
- updates the TrueType memory functions to take `Hinting` rather than `bool`

Fixes #708

skrifa/Cargo.toml

@@ -8,11 +8,6 @@ repository = "https://github.com/googlefonts/fontations"
 readme = "README.md"
 categories = ["text-processing", "parsing", "graphics"]
 
-[features]
-default = ["scale"]
-scale = []
-hinting = []
-
 [dependencies]
 read-fonts = { version = "0.13.1", path = "../read-fonts" }
 

skrifa/src/lib.rs

@@ -19,7 +19,6 @@ pub mod charmap;
 pub mod font;
 pub mod instance;
 pub mod metrics;
-#[cfg(feature = "scale")]
 pub mod scale;
 pub mod setting;
 pub mod string;

skrifa/src/scale/glyf/mem.rs

@@ -7,7 +7,7 @@ use read_fonts::{
     types::{F26Dot6, Fixed, Point},
 };
 
-use super::Outline;
+use super::{Hinting, Outline};
 
 /// Buffers used during glyph scaling.
 pub struct OutlineMemory<'a> {
@@ -22,11 +22,11 @@ pub struct OutlineMemory<'a> {
 }
 
 impl<'a> OutlineMemory<'a> {
-    pub(super) fn new(outline: &Outline, buf: &'a mut [u8], with_hinting: bool) -> Option<Self> {
+    pub(super) fn new(outline: &Outline, buf: &'a mut [u8], hinting: Hinting) -> Option<Self> {
         let (scaled, buf) = alloc_slice(buf, outline.points)?;
         let (unscaled, buf) = alloc_slice(buf, outline.max_other_points)?;
         // We only need original scaled points when hinting
-        let (original_scaled, buf) = if outline.has_hinting && with_hinting {
+        let (original_scaled, buf) = if outline.has_hinting && hinting != Hinting::None {
             alloc_slice(buf, outline.max_other_points)?
         } else {
             (Default::default(), buf)
@@ -157,9 +157,9 @@ mod tests {
             has_variations: true,
             has_overlaps: false,
         };
-        let required_size = outline_info.required_buffer_size(false);
+        let required_size = outline_info.required_buffer_size(Hinting::None);
         let mut buf = vec![0u8; required_size];
-        let memory = OutlineMemory::new(&outline_info, &mut buf, false).unwrap();
+        let memory = OutlineMemory::new(&outline_info, &mut buf, Hinting::None).unwrap();
         assert_eq!(memory.scaled.len(), outline_info.points);
         assert_eq!(memory.unscaled.len(), outline_info.max_other_points);
         // We don't allocate this buffer when hinting is disabled
@@ -190,8 +190,8 @@ mod tests {
         };
         // Required size adds 4 bytes slop to account for internal alignment
         // requirements. So subtract 5 to force a failure.
-        let not_enough = outline_info.required_buffer_size(false) - 5;
+        let not_enough = outline_info.required_buffer_size(Hinting::None) - 5;
         let mut buf = vec![0u8; not_enough];
-        assert!(OutlineMemory::new(&outline_info, &mut buf, false).is_none());
+        assert!(OutlineMemory::new(&outline_info, &mut buf, Hinting::None).is_none());
     }
 }

skrifa/src/scale/glyf/mod.rs

@@ -9,7 +9,7 @@ pub use hint::HinterOutline;
 pub use mem::OutlineMemory;
 pub use outline::{Outline, ScaledOutline};
 
-use super::Error;
+use super::{Error, Hinting};
 
 use read_fonts::{
     tables::{

skrifa/src/scale/glyf/outline.rs

@@ -7,7 +7,7 @@ use read_fonts::{
     types::{F26Dot6, Fixed, GlyphId, Pen, Point},
 };
 
-use super::OutlineMemory;
+use super::{Hinting, OutlineMemory};
 
 /// Represents the information necessary to scale a glyph outline.
 ///
@@ -48,9 +48,9 @@ pub struct Outline<'a> {
 impl<'a> Outline<'a> {
     /// Returns the minimum size in bytes required to scale an outline based
     /// on the computed sizes.
-    pub fn required_buffer_size(&self, with_hinting: bool) -> usize {
+    pub fn required_buffer_size(&self, hinting: Hinting) -> usize {
         let mut size = 0;
-        let hinting = with_hinting && self.has_hinting;
+        let hinting = self.has_hinting && hinting != Hinting::None;
         // Scaled, unscaled and (for hinting) original scaled points
         size += self.points * size_of::<Point<F26Dot6>>();
         // Unscaled and (if hinted) original scaled points
@@ -82,9 +82,9 @@ impl<'a> Outline<'a> {
     pub fn memory_from_buffer(
         &self,
         buf: &'a mut [u8],
-        with_hinting: bool,
+        hinting: Hinting,
     ) -> Option<OutlineMemory<'a>> {
-        OutlineMemory::new(self, buf, with_hinting)
+        OutlineMemory::new(self, buf, hinting)
     }
 }
 

skrifa/src/scale/mod.rs

@@ -167,9 +167,11 @@ use super::{
 /// Modes for hinting.
 ///
 /// Only the `glyf` source supports all hinting modes.
-#[cfg(feature = "hinting")]
 #[derive(Copy, Clone, PartialEq, Eq, Default, Debug)]
 pub enum Hinting {
+    /// Hinting is disabled.
+    #[default]
+    None,
     /// "Full" hinting mode. May generate rough outlines and poor horizontal
     /// spacing.
     Full,
@@ -181,7 +183,6 @@ pub enum Hinting {
     LightSubpixel,
     /// Same as light subpixel, but always prevents adjustment in the
     /// horizontal direction. This is the default mode.
-    #[default]
     VerticalSubpixel,
 }
 

skrifa/src/scale/scaler.rs

@@ -1,10 +1,8 @@
 use super::{
-    cff, glyf, Context, Error, NormalizedCoord, Pen, Result, Size, UniqueId, VariationSetting,
+    cff, glyf, Context, Error, Hinting, NormalizedCoord, Pen, Result, Size, UniqueId,
+    VariationSetting,
 };
 
-#[cfg(feature = "hinting")]
-use super::Hinting;
-
 use core::borrow::Borrow;
 use read_fonts::{
     types::{Fixed, GlyphId},
@@ -33,8 +31,7 @@ pub struct ScalerBuilder<'a> {
     context: &'a mut Context,
     cache_key: Option<UniqueId>,
     size: Size,
-    #[cfg(feature = "hinting")]
-    hint: Option<Hinting>,
+    hinting: Hinting,
 }
 
 impl<'a> ScalerBuilder<'a> {
@@ -46,8 +43,7 @@ impl<'a> ScalerBuilder<'a> {
             context,
             cache_key: None,
             size: Size::unscaled(),
-            #[cfg(feature = "hinting")]
-            hint: None,
+            hinting: Hinting::None,
         }
     }
 
@@ -70,9 +66,8 @@ impl<'a> ScalerBuilder<'a> {
     /// Sets the hinting mode.
     ///
     /// Passing `None` will disable hinting.
-    #[cfg(feature = "hinting")]
-    pub fn hint(mut self, hint: Option<Hinting>) -> Self {
-        self.hint = hint;
+    pub fn hint(mut self, hint: Hinting) -> Self {
+        self.hinting = hint;
         self
     }
 
@@ -153,8 +148,7 @@ impl<'a> ScalerBuilder<'a> {
         Scaler {
             size,
             coords,
-            #[cfg(feature = "hinting")]
-            hint: self.hint,
+            hinting: self.hinting,
             outlines,
         }
     }
@@ -206,8 +200,7 @@ impl<'a> ScalerBuilder<'a> {
 pub struct Scaler<'a> {
     size: f32,
     coords: &'a [NormalizedCoord],
-    #[cfg(feature = "hinting")]
-    hint: Option<Hinting>,
+    hinting: Hinting,
     outlines: Option<Outlines<'a>>,
 }
 
@@ -226,14 +219,7 @@ impl<'a> Scaler<'a> {
     /// in the given pen for the sequence of path commands that define the outline.
     pub fn outline(&mut self, glyph_id: GlyphId, pen: &mut impl Pen) -> Result<ScalerMetrics> {
         if let Some(outlines) = &mut self.outlines {
-            outlines.outline(
-                glyph_id,
-                self.size,
-                self.coords,
-                #[cfg(feature = "hinting")]
-                self.hint,
-                pen,
-            )
+            outlines.outline(glyph_id, self.size, self.coords, self.hinting, pen)
         } else {
             Err(Error::NoSources)
         }
@@ -254,18 +240,18 @@ impl<'a> Outlines<'a> {
         glyph_id: GlyphId,
         size: f32,
         coords: &'a [NormalizedCoord],
-        #[cfg(feature = "hinting")] hint: Option<Hinting>,
+        hinting: Hinting,
         pen: &mut impl Pen,
     ) -> Result<ScalerMetrics> {
         match self {
             Self::TrueType(scaler, buf) => {
                 let glyph = scaler.outline(glyph_id)?;
-                let buf_size = glyph.required_buffer_size(false);
+                let buf_size = glyph.required_buffer_size(hinting);
                 if buf.len() < buf_size {
                     buf.resize(buf_size, 0);
                 }
                 let memory = glyph
-                    .memory_from_buffer(&mut buf[..], false)
+                    .memory_from_buffer(&mut buf[..], hinting)
                     .ok_or(Error::InsufficientMemory)?;
                 let outline = scaler.scale(memory, &glyph, size, coords)?;
                 outline.to_path(pen)?;
@@ -281,11 +267,7 @@ impl<'a> Outlines<'a> {
                 }
                 // CFF only has a single hinting mode and FT enables it
                 // if any of the hinting load flags are set.
-                #[cfg(feature = "hinting")]
-                let hint = hint.is_some();
-                #[cfg(not(feature = "hinting"))]
-                let hint = false;
-                scaler.outline(subfont, glyph_id, coords, hint, pen)?;
+                scaler.outline(subfont, glyph_id, coords, hinting != Hinting::None, pen)?;
                 // CFF does not have overlap flags and hinting never adjusts
                 // horizontal metrics
                 Ok(ScalerMetrics::default())