LibGfx: Don't try to paint glyphs that aren't in a font

Fixes LadybirdBrowser#88
awesomekling · Jun 16, 2024 · 927194c · 927194c
1 parent 374da14
commit 927194c
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Showing 5 changed files with 16 additions and 11 deletions.
diff --git a/Userland/Libraries/LibAccelGfx/GlyphAtlas.cpp b/Userland/Libraries/LibAccelGfx/GlyphAtlas.cpp
@@ -25,12 +25,12 @@ void GlyphAtlas::update(HashMap<Gfx::Font const*, HashTable<u32>> const& unique_
     for (auto const& [font, code_points] : unique_glyphs) {
         for (auto const& code_point : code_points) {
             auto glyph = font->glyph(code_point);
+            if (!glyph.has_value())
+                continue;
             auto atlas_key = GlyphsTextureKey { font, code_point };
             if (!m_glyphs_texture_map.contains(atlas_key))
                 need_to_rebuild_texture = true;
-            if (glyph.bitmap()) {
-                glyph_bitmaps.set(atlas_key, *glyph.bitmap());
-            }
+            glyph_bitmaps.set(atlas_key, *glyph->bitmap());
         }
     }
 

diff --git a/Userland/Libraries/LibGfx/Font/Font.h b/Userland/Libraries/LibGfx/Font/Font.h
@@ -32,7 +32,7 @@ class Glyph {
 
     bool is_color_bitmap() const { return m_color_bitmap; }
 
-    RefPtr<Bitmap> bitmap() const { return m_bitmap; }
+    [[nodiscard]] NonnullRefPtr<Bitmap> bitmap() const { return m_bitmap; }
     float left_bearing() const { return m_left_bearing; }
     float advance() const { return m_advance; }
     float ascent() const { return m_ascent; }
@@ -116,8 +116,8 @@ class Font : public RefCounted<Font> {
     virtual int pixel_size_rounded_up() const = 0;
 
     virtual u16 weight() const = 0;
-    virtual Glyph glyph(u32 code_point) const = 0;
-    virtual Glyph glyph(u32 code_point, GlyphSubpixelOffset) const = 0;
+    virtual Optional<Glyph> glyph(u32 code_point) const = 0;
+    virtual Optional<Glyph> glyph(u32 code_point, GlyphSubpixelOffset) const = 0;
     virtual bool contains_glyph(u32 code_point) const = 0;
 
     virtual float glyph_left_bearing(u32 code_point) const = 0;

diff --git a/Userland/Libraries/LibGfx/Font/ScaledFont.cpp b/Userland/Libraries/LibGfx/Font/ScaledFont.cpp
@@ -80,15 +80,17 @@ bool ScaledFont::append_glyph_path_to(Gfx::Path& path, u32 glyph_id) const
     return m_font->append_glyph_path_to(path, glyph_id, m_x_scale, m_y_scale);
 }
 
-Gfx::Glyph ScaledFont::glyph(u32 code_point) const
+Optional<Glyph> ScaledFont::glyph(u32 code_point) const
 {
     return glyph(code_point, GlyphSubpixelOffset { 0, 0 });
 }
 
-Gfx::Glyph ScaledFont::glyph(u32 code_point, GlyphSubpixelOffset subpixel_offset) const
+Optional<Glyph> ScaledFont::glyph(u32 code_point, GlyphSubpixelOffset subpixel_offset) const
 {
     auto id = glyph_id_for_code_point(code_point);
     auto bitmap = rasterize_glyph(id, subpixel_offset);
+    if (!bitmap)
+        return {};
     auto metrics = glyph_metrics(id);
     return Gfx::Glyph(*bitmap, metrics.left_side_bearing, metrics.advance_width, metrics.ascender, m_font->has_color_bitmaps());
 }

diff --git a/Userland/Libraries/LibGfx/Font/ScaledFont.h b/Userland/Libraries/LibGfx/Font/ScaledFont.h
@@ -37,9 +37,9 @@ class ScaledFont final : public Gfx::Font {
     virtual Gfx::FontPixelMetrics pixel_metrics() const override;
     virtual u8 slope() const override { return m_font->slope(); }
     virtual u16 weight() const override { return m_font->weight(); }
-    virtual Gfx::Glyph glyph(u32 code_point) const override;
+    virtual Optional<Glyph> glyph(u32 code_point) const override;
     virtual float glyph_left_bearing(u32 code_point) const override;
-    virtual Glyph glyph(u32 code_point, GlyphSubpixelOffset) const override;
+    virtual Optional<Glyph> glyph(u32 code_point, GlyphSubpixelOffset) const override;
     virtual bool contains_glyph(u32 code_point) const override { return m_font->glyph_id_for_code_point(code_point) > 0; }
     virtual float glyph_width(u32 code_point) const override;
     virtual float glyph_or_emoji_width(Utf8CodePointIterator&) const override;

diff --git a/Userland/Libraries/LibGfx/Painter.cpp b/Userland/Libraries/LibGfx/Painter.cpp
@@ -849,7 +849,10 @@ FLATTEN void Painter::draw_glyph(FloatPoint point, u32 code_point, Font const& f
 {
     auto top_left = point + FloatPoint(font.glyph_left_bearing(code_point), 0);
     auto glyph_position = Gfx::GlyphRasterPosition::get_nearest_fit_for(top_left);
-    auto glyph = font.glyph(code_point, glyph_position.subpixel_offset);
+    auto maybe_glyph = font.glyph(code_point, glyph_position.subpixel_offset);
+    if (!maybe_glyph.has_value())
+        return;
+    auto glyph = maybe_glyph.release_value();
 
     if (glyph.is_color_bitmap()) {
         float scaled_width = glyph.advance();