LibGfx: Provide accessors to instruction data to OpenType::Font

These probably won't need to stick around forever, but will be helpful
for creating some debug utilities.

Userland/Libraries/LibGfx/Font/OpenType/Font.cpp

@@ -703,4 +703,25 @@ bool OS2::use_typographic_metrics() const
     return header().fs_selection & 0x80;
 }
 
+Optional<ReadonlyBytes> Font::font_program() const
+{
+    if (m_fpgm.has_value())
+        return m_fpgm->program_data();
+    return {};
+}
+
+Optional<ReadonlyBytes> Font::control_value_program() const
+{
+    if (m_prep.has_value())
+        return m_prep->program_data();
+    return {};
+}
+
+Optional<ReadonlyBytes> Font::glyph_program(u32 glyph_id) const
+{
+    auto glyph_offset = m_loca.get_glyph_offset(glyph_id);
+    auto glyph = m_glyf.glyph(glyph_offset);
+    return glyph.program();
+}
+
 }

Userland/Libraries/LibGfx/Font/OpenType/Font.h

@@ -38,6 +38,10 @@ public:
     virtual u8 slope() const override;
     virtual bool is_fixed_width() const override;
 
+    Optional<ReadonlyBytes> font_program() const;
+    Optional<ReadonlyBytes> control_value_program() const;
+    Optional<ReadonlyBytes> glyph_program(u32 glyph_id) const;
+
 private:
     enum class Offsets {
         NumTables = 4,

Userland/Libraries/LibGfx/Font/OpenType/Glyf.cpp

@@ -250,6 +250,13 @@ static void get_ttglyph_offsets(ReadonlyBytes slice, u32 num_points, u32 flags_o
     *y_offset = *x_offset + x_size;
 }
 
+ReadonlyBytes Glyf::Glyph::program() const
+{
+    auto instructions_start = m_num_contours * 2;
+    u16 num_instructions = be_u16(m_slice.offset_pointer(instructions_start));
+    return m_slice.slice(instructions_start + 2, num_instructions);
+}
+
 void Glyf::Glyph::rasterize_impl(Gfx::PathRasterizer& rasterizer, Gfx::AffineTransform const& transform) const
 {
     // Get offset for flags, x, and y.

Userland/Libraries/LibGfx/Font/OpenType/Glyf.h

@@ -69,6 +69,8 @@ public:
         int ascender() const { return m_ymax; }
         int descender() const { return m_ymin; }
 
+        ReadonlyBytes program() const;
+
     private:
         enum class Type {
             Simple,