Parse .glyphs grayscale colors

googlefonts · Mar 2, 2025 · 9d9eab9 · 9d9eab9
1 parent 3403986
commit 9d9eab9
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Showing 2 changed files with 109 additions and 12 deletions.
diff --git a/glyphs-reader/src/font.rs b/glyphs-reader/src/font.rs
@@ -383,21 +383,31 @@ impl FromPlist for Color {
         let stop_offset = tokenizer.parse::<f64>()?;
         tokenizer.eat(b')')?;
 
-        if colors.len() != 4 {
-            return Err(crate::plist::Error::UnexpectedNumberOfValues {
+        // See <https://github.com/googlefonts/glyphsLib/blob/c4db6b981d577f456d64ebe9993818770e170454/Lib/glyphsLib/builder/common.py#L41-L50>
+        match colors.len() {
+            // Grayscale
+            2 => Ok(Color {
+                r: colors[0],
+                g: colors[0],
+                b: colors[0],
+                a: colors[1],
+                stop_offset: stop_offset.into(),
+            }),
+            // RGB
+            4 => Ok(Color {
+                r: colors[0],
+                g: colors[1],
+                b: colors[2],
+                a: colors[3],
+                stop_offset: stop_offset.into(),
+            }),
+            // 5 is CMYK, match python by not supporting that
+            v => Err(crate::plist::Error::UnexpectedNumberOfValues {
                 value_type: "rgba values",
                 expected: 4,
-                actual: colors.len(),
-            });
+                actual: v,
+            }),
         }
-
-        Ok(Color {
-            r: colors[0],
-            g: colors[1],
-            b: colors[2],
-            a: colors[3],
-            stop_offset: stop_offset.into(),
-        })
     }
 }
 
@@ -3912,4 +3922,35 @@ mod tests {
                 .collect::<HashSet<_>>()
         );
     }
+
+    #[test]
+    fn parse_grayscale_colors() {
+        let font = Font::load(&glyphs3_dir().join("COLRv1-grayscale.glyphs")).unwrap();
+        assert_eq!(
+            vec![
+                Color {
+                    r: 64,
+                    g: 64,
+                    b: 64,
+                    a: 255,
+                    stop_offset: 0.into(),
+                },
+                Color {
+                    r: 0,
+                    g: 0,
+                    b: 0,
+                    a: 255,
+                    stop_offset: 1.into(),
+                },
+            ],
+            font.glyphs
+                .values()
+                .flat_map(|g| g
+                    .layers
+                    .iter()
+                    .flat_map(|l| l.shapes.iter())
+                    .flat_map(|s| (s.attributes().gradient.colors.iter().cloned())))
+                .collect::<Vec<_>>()
+        );
+    }
 }
diff --git a/resources/testdata/glyphs3/COLRv1-grayscale.glyphs b/resources/testdata/glyphs3/COLRv1-grayscale.glyphs
@@ -0,0 +1,56 @@
+{
+.appVersion = "3343";
+.formatVersion = 3;
+familyName = "New Font";
+fontMaster = (
+{
+id = m01;
+name = Regular;
+}
+);
+glyphs = (
+{
+glyphname = A;
+layers = (
+{
+attr = {
+color = 1;
+};
+layerId = m01;
+shapes = (
+{
+attr = {
+gradient = {
+colors = (
+(
+(64,255),
+0
+),
+(
+(0,255),
+1
+)
+);
+end = (0.9,0.9);
+start = (0.1,0.1);
+};
+};
+closed = 1;
+nodes = (
+(63,0,l),
+(542,0,l),
+(542,500,l),
+(63,500,l)
+);
+}
+);
+width = 600;
+}
+);
+unicode = 65;
+}
+);
+unitsPerEm = 1000;
+versionMajor = 1;
+versionMinor = 0;
+}