karm-media: Added kerning informations cache.

skift-org · Apr 18, 2024 · c25350e · c25350e
1 parent 6dc0d66
commit c25350e
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Showing 4 changed files with 13 additions and 6 deletions.
diff --git a/src/libs/karm-media/font-ttf.h b/src/libs/karm-media/font-ttf.h
@@ -14,6 +14,7 @@ struct TtfFontface : public Fontface {
     Ttf::Font _ttf;
     Map<Rune, Media::Glyph> _cachedEntries;
     Map<Media::Glyph, f64> _cachedAdvances;
+    Map<Cons<Media::Glyph>, f64> _cachedKerns;
 
     static Res<Strong<TtfFontface>> load(Sys::Mmap &&mmap) {
         auto ttf = try$(Ttf::Font::load(mmap.bytes()));
@@ -53,8 +54,14 @@ struct TtfFontface : public Fontface {
         return a;
     }
 
-    f64 kern(Glyph prev, Glyph curr) const override {
-        return _ttf.glyphKern(prev, curr);
+    f64 kern(Glyph prev, Glyph curr) override {
+        auto kern = _cachedKerns.get({prev, curr});
+        if (kern.has())
+            return kern.unwrap();
+
+        auto k = _ttf.glyphKern(prev, curr);
+        _cachedKerns.put({prev, curr}, k);
+        return k;
     }
 
     void contour(Gfx::Context &g, Glyph glyph) const override {

diff --git a/src/libs/karm-media/font-vga.h b/src/libs/karm-media/font-vga.h
@@ -35,7 +35,7 @@ struct VgaFontface : public Fontface {
         return 8;
     }
 
-    f64 kern(Glyph, Glyph) const override {
+    f64 kern(Glyph, Glyph) override {
         return 0;
     }
 

diff --git a/src/libs/karm-media/font.cpp b/src/libs/karm-media/font.cpp
@@ -43,7 +43,7 @@ f64 Font::advance(Glyph glyph) {
     return fontface->advance(glyph) * scale();
 }
 
-f64 Font::kern(Glyph prev, Glyph curr) const {
+f64 Font::kern(Glyph prev, Glyph curr) {
     return fontface->kern(prev, curr) * scale();
 }
 

diff --git a/src/libs/karm-media/font.h b/src/libs/karm-media/font.h
@@ -92,7 +92,7 @@ struct Fontface {
 
     virtual f64 advance(Glyph glyph) = 0;
 
-    virtual f64 kern(Glyph prev, Glyph curr) const = 0;
+    virtual f64 kern(Glyph prev, Glyph curr) = 0;
 
     virtual void contour(Gfx::Context &g, Glyph glyph) const = 0;
 
@@ -114,7 +114,7 @@ struct Font {
 
     f64 advance(Glyph glyph);
 
-    f64 kern(Glyph prev, Glyph curr) const;
+    f64 kern(Glyph prev, Glyph curr);
 
     FontMeasure measure(Glyph glyph);
 };