[Impeller] Retain embolden/skew font properties when rendering text glyphs (flutter#39378)

Author: bdero

impeller/typographer/backends/skia/text_frame_skia.cc

@@ -27,6 +27,8 @@ static Font ToFont(const SkTextBlobRunIterator& run, Scalar scale) {
   Font::Metrics metrics;
   metrics.scale = scale;
   metrics.point_size = font.getSize();
+  metrics.embolden = font.isEmbolden();
+  metrics.skewX = font.getSkewX();
 
   return Font{std::move(typeface), metrics};
 }

impeller/typographer/backends/skia/text_render_context_skia.cc

@@ -282,6 +282,11 @@ static std::shared_ptr<SkBitmap> CreateAtlasBitmap(const GlyphAtlas& atlas,
     SkFont sk_font(
         TypefaceSkia::Cast(*font_glyph.font.GetTypeface()).GetSkiaTypeface(),
         metrics.point_size);
+    sk_font.setEdging(SkFont::Edging::kAntiAlias);
+    sk_font.setHinting(SkFontHinting::kSlight);
+    sk_font.setEmbolden(metrics.embolden);
+    sk_font.setSkewX(metrics.skewX);
+
     auto glyph_color = SK_ColorWHITE;
 
     SkPaint glyph_paint;

impeller/typographer/font.h

@@ -11,6 +11,7 @@
 #include "impeller/base/comparable.h"
 #include "impeller/typographer/glyph.h"
 #include "impeller/typographer/typeface.h"
+#include "include/core/SkFont.h"
 
 namespace impeller {
 
@@ -38,9 +39,12 @@ class Font : public Comparable<Font> {
     /// The point size of the font.
     ///
     Scalar point_size = 12.0f;
+    bool embolden = false;
+    Scalar skewX = 0.0f;
 
     constexpr bool operator==(const Metrics& o) const {
-      return scale == o.scale && point_size == o.point_size;
+      return scale == o.scale && point_size == o.point_size &&
+             embolden == o.embolden && skewX == o.skewX;
     }
   };