push_clip()/pop_clip() in paint_v0

Necessary for getting the proper glyph extents, and matches HarfBuzz.

Author: valadaptive

src/tables/colr.rs

@@ -937,15 +937,16 @@ impl<'a> Table<'a> {
         let layers = self.layers.slice(start..end)?;
 
         for layer in layers {
+            painter.outline_glyph(layer.glyph_id);
+            painter.push_clip();
             if layer.palette_index == 0xFFFF {
                 // A special case.
-                painter.outline_glyph(layer.glyph_id);
                 painter.paint(Paint::Solid(foreground_color));
             } else {
                 let color = self.palettes.get(palette, layer.palette_index)?;
-                painter.outline_glyph(layer.glyph_id);
                 painter.paint(Paint::Solid(color));
             }
+            painter.pop_clip();
         }
 
         Some(())

tests/tables/colr.rs

@@ -65,23 +65,35 @@ fn basic() {
     assert_eq!(
         paint(2).unwrap(), vec![
             Command::OutlineGlyph(GlyphId(12)),
+            Command::PushClip,
             Command::Paint(c.clone()),
+            Command::PopClip,
             Command::OutlineGlyph(GlyphId(13)),
-            Command::Paint(a.clone())]
-    );
+            Command::PushClip,
+            Command::Paint(a.clone()),
+            Command::PopClip
+        ]);
 
     assert_eq!(paint(3).unwrap(), vec![
         Command::OutlineGlyph(GlyphId(10)),
+        Command::PushClip,
         Command::Paint(c.clone()),
+        Command::PopClip,
         Command::OutlineGlyph(GlyphId(11)),
+        Command::PushClip,
         Command::Paint(b.clone()),
+        Command::PopClip,
         Command::OutlineGlyph(GlyphId(12)),
+        Command::PushClip,
         Command::Paint(c.clone()),
+        Command::PopClip,
     ]);
 
     assert_eq!(paint(7).unwrap(), vec![
         Command::OutlineGlyph(GlyphId(11)),
+        Command::PushClip,
         Command::Paint(b.clone()),
+        Command::PopClip,
     ]);
 }