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| author | Andreas Kling <kling@serenityos.org> | 2022-12-19 13:24:22 +0100 |
|---|---|---|
| committer | Andreas Kling <kling@serenityos.org> | 2022-12-21 08:44:22 +0100 |
| commit | 61be11960b901d7cc159db135b0c5bb484f40002 (patch) | |
| tree | 3055aa0a6b30da12f7121bc7dbf4d3c64ddf6100 /Userland | |
| parent | 23638a3b3a417629dcad058ef61145809901fdc4 (diff) | |
| download | serenity-61be11960b901d7cc159db135b0c5bb484f40002.zip | |
LibGfx/OpenType: Read "head" table using a C++ struct
Instead of fidgeting with offsets and manually reading out big-endian
values, we now declare the "head" table as a C++ struct and use the
BigEndian<T> template to deal with byte order.
Diffstat (limited to 'Userland')
| -rw-r--r-- | Userland/Libraries/LibGfx/Font/OpenType/Font.cpp | 19 | ||||
| -rw-r--r-- | Userland/Libraries/LibGfx/Font/OpenType/Tables.h | 42 |
2 files changed, 39 insertions, 22 deletions
diff --git a/Userland/Libraries/LibGfx/Font/OpenType/Font.cpp b/Userland/Libraries/LibGfx/Font/OpenType/Font.cpp index 1f1de38e64..7ccab56f72 100644 --- a/Userland/Libraries/LibGfx/Font/OpenType/Font.cpp +++ b/Userland/Libraries/LibGfx/Font/OpenType/Font.cpp @@ -52,7 +52,7 @@ u32 tag_from_str(char const* str) Optional<Head> Head::from_slice(ReadonlyBytes slice) { - if (slice.size() < (size_t)Sizes::Table) { + if (slice.size() < sizeof(FontHeaderTable)) { return {}; } return Head(slice); @@ -60,43 +60,42 @@ Optional<Head> Head::from_slice(ReadonlyBytes slice) u16 Head::units_per_em() const { - return be_u16(m_slice.offset_pointer((u32)Offsets::UnitsPerEM)); + return header().units_per_em; } i16 Head::xmin() const { - return be_i16(m_slice.offset_pointer((u32)Offsets::XMin)); + return header().x_min; } i16 Head::ymin() const { - return be_i16(m_slice.offset_pointer((u32)Offsets::YMin)); + return header().y_min; } i16 Head::xmax() const { - return be_i16(m_slice.offset_pointer((u32)Offsets::XMax)); + return header().x_max; } i16 Head::ymax() const { - return be_i16(m_slice.offset_pointer((u32)Offsets::YMax)); + return header().y_max; } u16 Head::style() const { - return be_u16(m_slice.offset_pointer((u32)Offsets::Style)); + return header().mac_style; } u16 Head::lowest_recommended_ppem() const { - return be_u16(m_slice.offset_pointer((u32)Offsets::LowestRecPPEM)); + return header().lowest_rec_ppem; } IndexToLocFormat Head::index_to_loc_format() const { - i16 raw = be_i16(m_slice.offset_pointer((u32)Offsets::IndexToLocFormat)); - switch (raw) { + switch (header().index_to_loc_format) { case 0: return IndexToLocFormat::Offset16; case 1: diff --git a/Userland/Libraries/LibGfx/Font/OpenType/Tables.h b/Userland/Libraries/LibGfx/Font/OpenType/Tables.h index eabd18b48a..d49dd53deb 100644 --- a/Userland/Libraries/LibGfx/Font/OpenType/Tables.h +++ b/Userland/Libraries/LibGfx/Font/OpenType/Tables.h @@ -19,6 +19,15 @@ enum class IndexToLocFormat { Offset32, }; +struct Fixed { + BigEndian<u16> integer; + BigEndian<u16> fraction; +}; + +struct LongDateTime { + BigEndian<u64> value; +}; + // https://learn.microsoft.com/en-us/typography/opentype/spec/head // head: Font Header Table class Head { @@ -34,20 +43,29 @@ public: IndexToLocFormat index_to_loc_format() const; private: - enum class Offsets { - UnitsPerEM = 18, - XMin = 36, - YMin = 38, - XMax = 40, - YMax = 42, - Style = 44, - LowestRecPPEM = 46, - IndexToLocFormat = 50, - }; - enum class Sizes { - Table = 54, + struct FontHeaderTable { + BigEndian<u16> major_version; + BigEndian<u16> minor_version; + Fixed font_revision; + BigEndian<u32> checksum_adjustment; + BigEndian<u32> magic_number; + BigEndian<u16> flags; + BigEndian<u16> units_per_em; + LongDateTime created; + LongDateTime modified; + BigEndian<i16> x_min; + BigEndian<i16> y_min; + BigEndian<i16> x_max; + BigEndian<i16> y_max; + BigEndian<u16> mac_style; + BigEndian<u16> lowest_rec_ppem; + BigEndian<i16> font_direction_hint; + BigEndian<i16> index_to_loc_format; + BigEndian<i16> glyph_data_format; }; + FontHeaderTable const& header() const { return *bit_cast<FontHeaderTable const*>(m_slice.data()); } + Head(ReadonlyBytes slice) : m_slice(slice) { |