Adjust flags to permit toggling flatten

googlefonts · Apr 18, 2023 · 9df4b92 · 9df4b92
1 parent ca772e6
commit 9df4b92
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Showing 4 changed files with 26 additions and 13 deletions.
diff --git a/fontc/src/args.rs b/fontc/src/args.rs
@@ -21,12 +21,15 @@ pub struct Args {
     #[arg(long, default_value = "false")]
     pub emit_debug: bool,
 
-    /// Whether to Try Hard(tm) to match fontmake (Python) behavior in cases where there are other options.
-    ///
-    /// See <https://github.com/googlefonts/fontmake-rs/pull/123> for an example of
-    /// where this matters.
+    /// In cases where a source glyph uses a mixture of components and contours, convert
+    /// all the components to contours.
     #[arg(long, default_value = "true")]
-    pub match_legacy: bool,
+    pub prefer_simple_glyphs: bool,
+
+    /// Eliminate component references to other glyphs using components, emitting only
+    /// component references to simple (contour) glyphs.
+    #[arg(long, default_value = "true")]
+    pub flatten_components: bool,
 
     /// Working directory for the build process. If emit-ir is on, written here.
     #[arg(short, long, default_value = "build")]
@@ -44,7 +47,8 @@ impl Args {
 
         flags.set(Flags::EMIT_IR, self.emit_ir);
         flags.set(Flags::EMIT_DEBUG, self.emit_debug);
-        flags.set(Flags::MATCH_LEGACY, self.match_legacy);
+        flags.set(Flags::PREFER_SIMPLE_GLYPHS, self.prefer_simple_glyphs);
+        flags.set(Flags::FLATTEN_COMPONENTS, self.flatten_components);
 
         flags
     }
@@ -65,7 +69,8 @@ impl Args {
             emit_ir: true,
             emit_debug: false,
             build_dir: build_dir.to_path_buf(),
-            match_legacy: true,
+            prefer_simple_glyphs: Flags::default().contains(Flags::PREFER_SIMPLE_GLYPHS),
+            flatten_components: Flags::default().contains(Flags::FLATTEN_COMPONENTS),
         }
     }
 }
diff --git a/fontc/src/lib.rs b/fontc/src/lib.rs
@@ -1006,11 +1006,14 @@ mod tests {
         assert!(feature_ttf.is_file(), "Should have written {feature_ttf:?}");
     }
 
-    fn build_contour_and_composite_glyph(temp_dir: &TempDir, match_legacy: bool) -> ir::Glyph {
+    fn build_contour_and_composite_glyph(
+        temp_dir: &TempDir,
+        prefer_simple_glyphs: bool,
+    ) -> ir::Glyph {
         let build_dir = temp_dir.path();
 
         let mut args = Args::for_test(build_dir, "glyphs2/MixedContourComponent.glyphs");
-        args.match_legacy = match_legacy; // <-- important :)
+        args.prefer_simple_glyphs = prefer_simple_glyphs; // <-- important :)
         let result = compile(args);
 
         let glyph = result

diff --git a/fontir/src/glyph.rs b/fontir/src/glyph.rs
@@ -300,7 +300,8 @@ impl Work<Context, WorkError> for FinalizeStaticMetadataWork {
                 !has_consistent_2x2_transforms || has_components_and_contours(glyph)
             })
         {
-            if !has_consistent_2x2_transforms || context.flags.contains(Flags::MATCH_LEGACY) {
+            if !has_consistent_2x2_transforms || context.flags.contains(Flags::PREFER_SIMPLE_GLYPHS)
+            {
                 if !has_consistent_2x2_transforms {
                     debug!(
                         "Coalescing'{0}' into a simple glyph because component 2x2s vary across the designspace",

diff --git a/fontir/src/orchestration.rs b/fontir/src/orchestration.rs
@@ -26,8 +26,11 @@ bitflags! {
         const EMIT_IR = 0b00000001;
         // If set additional debug files will be emitted to disk
         const EMIT_DEBUG = 0b00000010;
-        // If set seek to match fontmake (python) behavior even at cost of abandoning optimizations
-        const MATCH_LEGACY = 0b00000100;
+        // If set, a glyph with contours and components will be converted to a simple (contour) glyph
+        const PREFER_SIMPLE_GLYPHS = 0b00000100;
+        // If set, a composite that references another composite will replace that composite with the
+        // glyph(s) it references until only simple (contour) glyphs are referenced
+        const FLATTEN_COMPONENTS = 0b00001000;
     }
 }
 
@@ -69,8 +72,9 @@ macro_rules! context_accessors {
 }
 
 impl Default for Flags {
+    /// Match the way gftools configures fontmake by default
     fn default() -> Self {
-        Flags::MATCH_LEGACY
+        Flags::PREFER_SIMPLE_GLYPHS | Flags::FLATTEN_COMPONENTS
     }
 }