[BugFix] enable slight hinting for skity

Author: hfuttyh

public/textra/platform/skity/skity_canvas_helper.h

@@ -95,6 +95,7 @@ class SkityCanvasHelper : public ICanvasHelper {
     }
     std::vector<skity::TextRun> runs;
     skity::Font skity_font(typeface->GetTypeface(), paint->GetTextSize());
+    skity_font.SetHinting(skity::Font::FontHinting::kSlight);
     skity_font.SetEmbolden(painter->IsBold());
     skity_font.SetSkewX(painter->IsItalic() ? -0.25f : 0);
     runs.emplace_back(skity_font, glyph_vector, p_x, p_y);

src/ports/shaper/skshaper/font.h

@@ -13,6 +13,12 @@
 
 namespace ttoffice {
 namespace tttext {
+enum class FontHinting {
+  kNone,    //!< glyph outlines unchanged
+  kSlight,  //!< minimal modification to improve constrast
+  kNormal,  //!< glyph outlines modified to improve constrast
+  kFull,    //!< modifies glyph outlines for maximum constrast
+};
 class Font final {
  public:
   Font() = delete;
@@ -54,6 +60,8 @@ class Font final {
   bool IsFakeBold() const { return fake_bold_; }
   void SetSkewX(float skew_x) { skew_x_ = skew_x; }
   float SkewX() const { return skew_x_; }
+  void SetHinting(FontHinting hinting) { hinting_ = hinting; }
+  FontHinting GetHinting() const { return hinting_; }
 
  private:
   std::shared_ptr<ITypefaceHelper> typeface_;
@@ -62,6 +70,7 @@ class Font final {
   bool fake_bold_ = false;
   float scale_x_ = 1.0f;
   float skew_x_ = 0.f;
+  FontHinting hinting_ = FontHinting::kSlight;
 };
 }  // namespace tttext
 }  // namespace ttoffice

src/ports/shaper/skshaper/one_line_shaper.cc

@@ -587,8 +587,8 @@ bool OneLineShaper::shape(const char32_t* content, uint32_t len,
   matchResolvedFonts(style, [&](std::shared_ptr<ITypefaceHelper> typeface) {
     // Create one more font to try
     Font font(typeface, style.GetFontSize());
-    //    font.setEdging(SkFont::Edging::kAntiAlias);
-    //    font.setHinting(SkFontHinting::kSlight);
+    // font.setEdging(SkFont::Edging::kAntiAlias);
+    font.SetHinting(FontHinting::kSlight);
     font.SetSubpixel(true);
 
     // Apply fake bold and/or italic settings to the font if the