LibGfx/OpenType: Read "glyf" table header using a C++ struct

2 files changed, 15 insertions, 15 deletions

diff --git a/Userland/Libraries/LibGfx/Font/OpenType/Glyf.cpp b/Userland/Libraries/LibGfx/Font/OpenType/Glyf.cpp
index 85aba856f1..3e8e8e7197 100644
--- a/Userland/Libraries/LibGfx/Font/OpenType/Glyf.cpp
+++ b/Userland/Libraries/LibGfx/Font/OpenType/Glyf.cpp
@@ -358,13 +358,14 @@ RefPtr<Gfx::Bitmap> Glyf::Glyph::rasterize_simple(i16 font_ascender, i16 font_de
 
 Glyf::Glyph Glyf::glyph(u32 offset) const
 {
-    VERIFY(m_slice.size() >= offset + (u32)Sizes::GlyphHeader);
-    i16 num_contours = be_i16(m_slice.offset_pointer(offset));
-    i16 xmin = be_i16(m_slice.offset_pointer(offset + (u32)Offsets::XMin));
-    i16 ymin = be_i16(m_slice.offset_pointer(offset + (u32)Offsets::YMin));
-    i16 xmax = be_i16(m_slice.offset_pointer(offset + (u32)Offsets::XMax));
-    i16 ymax = be_i16(m_slice.offset_pointer(offset + (u32)Offsets::YMax));
-    auto slice = ReadonlyBytes(m_slice.offset_pointer(offset + (u32)Sizes::GlyphHeader), m_slice.size() - offset - (u32)Sizes::GlyphHeader);
+    VERIFY(m_slice.size() >= offset + sizeof(GlyphHeader));
+    auto const& glyph_header = *bit_cast<GlyphHeader const*>(m_slice.offset_pointer(offset));
+    i16 num_contours = glyph_header.number_of_contours;
+    i16 xmin = glyph_header.x_min;
+    i16 ymin = glyph_header.y_min;
+    i16 xmax = glyph_header.x_max;
+    i16 ymax = glyph_header.y_max;
+    auto slice = m_slice.slice(offset + sizeof(GlyphHeader));
     return Glyph(slice, xmin, ymin, xmax, ymax, num_contours);
 }
 
diff --git a/Userland/Libraries/LibGfx/Font/OpenType/Glyf.h b/Userland/Libraries/LibGfx/Font/OpenType/Glyf.h
index 80dbebb805..b487534cc8 100644
--- a/Userland/Libraries/LibGfx/Font/OpenType/Glyf.h
+++ b/Userland/Libraries/LibGfx/Font/OpenType/Glyf.h
@@ -148,14 +148,13 @@ public:
     Glyph glyph(u32 offset) const;
 
 private:
-    enum class Offsets {
-        XMin = 2,
-        YMin = 4,
-        XMax = 6,
-        YMax = 8,
-    };
-    enum class Sizes {
-        GlyphHeader = 10,
+    // https://learn.microsoft.com/en-us/typography/opentype/spec/glyf#glyph-headers
+    struct GlyphHeader {
+        BigEndian<i16> number_of_contours;
+        BigEndian<i16> x_min;
+        BigEndian<i16> y_min;
+        BigEndian<i16> x_max;
+        BigEndian<i16> y_max;
     };
 
     ReadonlyBytes m_slice;