Store required font metrics on TextFragment

components/layout_2020/display_list/mod.rs

@@ -87,7 +87,7 @@ impl Fragment {
                     .to_physical(t.parent_style.writing_mode, containing_block)
                     .translate(containing_block.origin.to_vector());
                 let mut baseline_origin = rect.origin.clone();
-                baseline_origin.y += t.ascent;
+                baseline_origin.y += t.font_metrics.ascent;
                 let glyphs = glyphs(&t.glyphs, baseline_origin);
                 if glyphs.is_empty() {
                     return;

components/layout_2020/flow/inline.rs

@@ -9,7 +9,7 @@ use crate::flow::FlowLayout;
 use crate::formatting_contexts::IndependentFormattingContext;
 use crate::fragments::{
     AbsoluteOrFixedPositionedFragment, AnonymousFragment, BoxFragment, CollapsedBlockMargins,
-    DebugId, Fragment, TextFragment,
+    DebugId, FontMetrics, Fragment, TextFragment,
 };
 use crate::geom::flow_relative::{Rect, Sides, Vec2};
 use crate::positioned::{
@@ -631,8 +631,7 @@ fn layout_atomic(
 }
 
 struct BreakAndShapeResult {
-    font_ascent: Au,
+    font_metrics: FontMetrics,
-    font_line_gap: Au,
     font_key: FontInstanceKey,
     runs: Vec<GlyphRun>,
     break_at_start: bool,
@@ -699,8 +698,7 @@ impl TextRun {
             );
 
             BreakAndShapeResult {
-                font_ascent: font.metrics.ascent,
+                font_metrics: (&font.metrics).into(),
-                font_line_gap: font.metrics.line_gap,
                 font_key: font.font_key,
                 runs,
                 break_at_start,
@@ -712,8 +710,7 @@ impl TextRun {
         use style::values::generics::text::LineHeight;
 
         let BreakAndShapeResult {
-            font_ascent,
+            font_metrics,
-            font_line_gap,
             font_key,
             runs,
             break_at_start: _,
@@ -750,7 +747,7 @@ impl TextRun {
                 }
             }
             let line_height = match self.parent_style.get_inherited_text().line_height {
-                LineHeight::Normal => font_line_gap.into(),
+                LineHeight::Normal => font_metrics.line_gap,
                 LineHeight::Number(n) => font_size * n.0,
                 LineHeight::Length(l) => l.0,
             };
@@ -775,7 +772,7 @@ impl TextRun {
                     debug_id: DebugId::new(),
                     parent_style: self.parent_style.clone(),
                     rect,
-                    ascent: font_ascent.into(),
+                    font_metrics,
                     font_key,
                     glyphs,
                 }));

components/layout_2020/fragments.rs

@@ -7,6 +7,7 @@ use crate::geom::{PhysicalPoint, PhysicalRect};
 #[cfg(debug_assertions)]
 use crate::layout_debug;
 use crate::positioned::HoistedFragmentId;
+use gfx::font::FontMetrics as GfxFontMetrics;
 use gfx::text::glyph::GlyphStore;
 use gfx_traits::print_tree::PrintTree;
 #[cfg(not(debug_assertions))]
@@ -86,6 +87,29 @@ pub(crate) struct AnonymousFragment {
     pub scrollable_overflow: PhysicalRect<Length>,
 }
 
+#[derive(Clone, Copy, Serialize)]
+pub(crate) struct FontMetrics {
+    pub ascent: Length,
+    pub line_gap: Length,
+    pub underline_offset: Length,
+    pub underline_size: Length,
+    pub strikeout_offset: Length,
+    pub strikeout_size: Length,
+}
+
+impl From<&GfxFontMetrics> for FontMetrics {
+    fn from(metrics: &GfxFontMetrics) -> FontMetrics {
+        FontMetrics {
+            ascent: metrics.ascent.into(),
+            line_gap: metrics.line_gap.into(),
+            underline_offset: metrics.underline_offset.into(),
+            underline_size: metrics.underline_size.into(),
+            strikeout_offset: metrics.strikeout_offset.into(),
+            strikeout_size: metrics.strikeout_size.into(),
+        }
+    }
+}
+
 #[derive(Serialize)]
 pub(crate) struct TextFragment {
     pub debug_id: DebugId,
@@ -93,7 +117,7 @@ pub(crate) struct TextFragment {
     #[serde(skip_serializing)]
     pub parent_style: ServoArc<ComputedValues>,
     pub rect: Rect<Length>,
-    pub ascent: Length,
+    pub font_metrics: FontMetrics,
     #[serde(skip_serializing)]
     pub font_key: FontInstanceKey,
     pub glyphs: Vec<Arc<GlyphStore>>,