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LibTTF: Address code-style comments, gracefully handle load failures.

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This commit is contained in:
Srimanta Barua 2020-06-14 18:32:39 +05:30 • committed by Andreas Kling
parent ec08e9e780
commit 3b31f069f0
7 changed files with 336 additions and 248 deletions
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10
Libraries/LibTTF/Cmap.cpp
View file

@ -24,8 +24,8 @@
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/ */
#include "Cmap.h"
#include <AK/Optional.h> #include <AK/Optional.h>
#include <LibTTF/Cmap.h>
namespace TTF { namespace TTF {
@ -148,4 +148,12 @@ u32 Cmap::glyph_id_for_codepoint(u32 codepoint) const
return subtable.glyph_id_for_codepoint(codepoint); return subtable.glyph_id_for_codepoint(codepoint);
} }
Optional<Cmap> Cmap::from_slice(const ByteBuffer& slice)
{
if (slice.size() < (size_t) Sizes::TableHeader) {
return {};
}
return Cmap(slice);
}
} }

17
Libraries/LibTTF/Cmap.h
View file

@ -96,17 +96,11 @@ public:
u32 glyph_id_for_codepoint_table_12(u32 codepoint) const; u32 glyph_id_for_codepoint_table_12(u32 codepoint) const;
ByteBuffer m_slice; ByteBuffer m_slice;
u16 m_raw_platform_id; u16 m_raw_platform_id { 0 };
u16 m_encoding_id; u16 m_encoding_id { 0 };
}; };
Cmap() {} static Optional<Cmap> from_slice(const ByteBuffer&);
Cmap(const ByteBuffer& slice)
: m_slice(slice)
{
ASSERT(m_slice.size() > (size_t) Sizes::TableHeader);
}
u32 num_subtables() const; u32 num_subtables() const;
Optional<Subtable> subtable(u32 index) const; Optional<Subtable> subtable(u32 index) const;
void set_active_index(u32 index) { m_active_index = index; } void set_active_index(u32 index) { m_active_index = index; }
@ -124,6 +118,11 @@ private:
EncodingRecord = 8, EncodingRecord = 8,
}; };
Cmap(const ByteBuffer& slice)
: m_slice(slice)
{
}
ByteBuffer m_slice; ByteBuffer m_slice;
u32 m_active_index { UINT32_MAX }; u32 m_active_index { UINT32_MAX };
}; };

245
Libraries/LibTTF/Font.cpp
View file

@ -24,15 +24,16 @@
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/ */
#include "Cmap.h" #include "AK/ByteBuffer.h"
#include "Font.h"
#include "Glyf.h"
#include "Tables.h"
#include <AK/LogStream.h> #include <AK/LogStream.h>
#include <AK/Utf8View.h>
#include <AK/Utf32View.h> #include <AK/Utf32View.h>
#include <bits/stdint.h> #include <AK/Utf8View.h>
#include <LibCore/File.h> #include <LibCore/File.h>
#include <LibTTF/Cmap.h>
#include <LibTTF/Font.h>
#include <LibTTF/Glyf.h>
#include <LibTTF/Tables.h>
#include <bits/stdint.h>
#include <math.h> #include <math.h>
namespace TTF { namespace TTF {
@ -62,6 +63,14 @@ u32 tag_from_str(const char *str)
return be_u32((const u8*)str); return be_u32((const u8*)str);
} }
Optional<Head> Head::from_slice(const ByteBuffer& slice)
{
if (slice.size() < (size_t)Sizes::Table) {
return {};
}
return Head(slice);
}
u16 Head::units_per_em() const u16 Head::units_per_em() const
{ {
return be_u16(m_slice.offset_pointer((u32)Offsets::UnitsPerEM)); return be_u16(m_slice.offset_pointer((u32)Offsets::UnitsPerEM));
@ -96,15 +105,20 @@ IndexToLocFormat Head::index_to_loc_format() const
{ {
i16 raw = be_i16(m_slice.offset_pointer((u32)Offsets::IndexToLocFormat)); i16 raw = be_i16(m_slice.offset_pointer((u32)Offsets::IndexToLocFormat));
switch (raw) { switch (raw) {
case 0: case 0: return IndexToLocFormat::Offset16;
return IndexToLocFormat::Offset16; case 1: return IndexToLocFormat::Offset32;
case 1: default: ASSERT_NOT_REACHED();
return IndexToLocFormat::Offset32;
default:
ASSERT_NOT_REACHED();
} }
} }
Optional<Hhea> Hhea::from_slice(const ByteBuffer& slice)
{
if (slice.size() < (size_t)Sizes::Table) {
return {};
}
return Hhea(slice);
}
i16 Hhea::ascender() const i16 Hhea::ascender() const
{ {
return be_i16(m_slice.offset_pointer((u32)Offsets::Ascender)); return be_i16(m_slice.offset_pointer((u32)Offsets::Ascender));
@ -130,6 +144,27 @@ u16 Hhea::number_of_h_metrics() const
return be_u16(m_slice.offset_pointer((u32)Offsets::NumberOfHMetrics)); return be_u16(m_slice.offset_pointer((u32)Offsets::NumberOfHMetrics));
} }
Optional<Maxp> Maxp::from_slice(const ByteBuffer& slice)
{
if (slice.size() < (size_t)Sizes::TableV0p5) {
return {};
}
return Maxp(slice);
}
u16 Maxp::num_glyphs() const
{
return be_u16(m_slice.offset_pointer((u32)Offsets::NumGlyphs));
}
Optional<Hmtx> Hmtx::from_slice(const ByteBuffer& slice, u32 num_glyphs, u32 number_of_h_metrics)
{
if (slice.size() < number_of_h_metrics * (u32)Sizes::LongHorMetric + (num_glyphs - number_of_h_metrics) * (u32)Sizes::LeftSideBearing) {
return {};
}
return Hmtx(slice, num_glyphs, number_of_h_metrics);
}
GlyphHorizontalMetrics Hmtx::get_glyph_horizontal_metrics(u32 glyph_id) const GlyphHorizontalMetrics Hmtx::get_glyph_horizontal_metrics(u32 glyph_id) const
{ {
ASSERT(glyph_id < m_num_glyphs); ASSERT(glyph_id < m_num_glyphs);
@ -151,11 +186,6 @@ GlyphHorizontalMetrics Hmtx::get_glyph_horizontal_metrics(u32 glyph_id) const
}; };
} }
u16 Maxp::num_glyphs() const
{
return be_u16(m_slice.offset_pointer((u32) Offsets::NumGlyphs));
}
RefPtr<Font> Font::load_from_file(const StringView& path, unsigned index) RefPtr<Font> Font::load_from_file(const StringView& path, unsigned index)
{ {
auto file_or_error = Core::File::open(String(path), Core::IODevice::ReadOnly); auto file_or_error = Core::File::open(String(path), Core::IODevice::ReadOnly);
@ -181,7 +211,7 @@ RefPtr<Font> Font::load_from_file(const StringView& path, unsigned index)
return nullptr; return nullptr;
} }
u32 offset = be_u32(buffer.offset_pointer((u32)Sizes::TTCHeaderV1 + sizeof(u32) * index)); u32 offset = be_u32(buffer.offset_pointer((u32)Sizes::TTCHeaderV1 + sizeof(u32) * index));
return adopt(*new Font(move(buffer), offset)); return load_from_offset(move(buffer), offset);
} }
if (tag == tag_from_str("OTTO")) { if (tag == tag_from_str("OTTO")) {
dbg() << "CFF fonts not supported yet"; dbg() << "CFF fonts not supported yet";
@ -191,99 +221,138 @@ RefPtr<Font> Font::load_from_file(const StringView& path, unsigned index)
dbg() << "Not a valid font"; dbg() << "Not a valid font";
return nullptr; return nullptr;
} }
return adopt(*new Font(move(buffer), 0)); return load_from_offset(move(buffer), 0);
} }
// FIXME: "loca" and "glyf" are not available for CFF fonts. // FIXME: "loca" and "glyf" are not available for CFF fonts.
Font::Font(ByteBuffer&& buffer, u32 offset) RefPtr<Font> Font::load_from_offset(ByteBuffer&& buffer, u32 offset)
: m_buffer(move(buffer))
{ {
ASSERT(m_buffer.size() >= offset + (u32) Sizes::OffsetTable); if (buffer.size() < offset + (u32)Sizes::OffsetTable) {
Optional<ByteBuffer> head_slice = {}; dbg() << "Font file too small";
Optional<ByteBuffer> hhea_slice = {}; return nullptr;
Optional<ByteBuffer> maxp_slice = {}; }
Optional<ByteBuffer> hmtx_slice = {};
Optional<ByteBuffer> cmap_slice = {};
Optional<ByteBuffer> loca_slice = {};
Optional<ByteBuffer> glyf_slice = {};
//auto sfnt_version = be_u32(data + offset); Optional<ByteBuffer> opt_head_slice = {};
auto num_tables = be_u16(m_buffer.offset_pointer(offset + (u32) Offsets::NumTables)); Optional<ByteBuffer> opt_hhea_slice = {};
ASSERT(m_buffer.size() >= offset + (u32) Sizes::OffsetTable + num_tables * (u32) Sizes::TableRecord); Optional<ByteBuffer> opt_maxp_slice = {};
Optional<ByteBuffer> opt_hmtx_slice = {};
Optional<ByteBuffer> opt_cmap_slice = {};
Optional<ByteBuffer> opt_loca_slice = {};
Optional<ByteBuffer> opt_glyf_slice = {};
Optional<Head> opt_head = {};
Optional<Hhea> opt_hhea = {};
Optional<Maxp> opt_maxp = {};
Optional<Hmtx> opt_hmtx = {};
Optional<Cmap> opt_cmap = {};
Optional<Loca> opt_loca = {};
auto num_tables = be_u16(buffer.offset_pointer(offset + (u32)Offsets::NumTables));
if (buffer.size() < offset + (u32)Sizes::OffsetTable + num_tables * (u32)Sizes::TableRecord) {
dbg() << "Font file too small";
return nullptr;
}
for (auto i = 0; i < num_tables; i++) { for (auto i = 0; i < num_tables; i++) {
u32 record_offset = offset + (u32)Sizes::OffsetTable + i * (u32)Sizes::TableRecord; u32 record_offset = offset + (u32)Sizes::OffsetTable + i * (u32)Sizes::TableRecord;
u32 tag = be_u32(m_buffer.offset_pointer(record_offset)); u32 tag = be_u32(buffer.offset_pointer(record_offset));
u32 table_offset = be_u32(m_buffer.offset_pointer(record_offset + (u32) Offsets::TableRecord_Offset)); u32 table_offset = be_u32(buffer.offset_pointer(record_offset + (u32)Offsets::TableRecord_Offset));
u32 table_length = be_u32(m_buffer.offset_pointer(record_offset + (u32) Offsets::TableRecord_Length)); u32 table_length = be_u32(buffer.offset_pointer(record_offset + (u32)Offsets::TableRecord_Length));
ASSERT(m_buffer.size() >= table_offset + table_length); if (buffer.size() < table_offset + table_length) {
auto buffer = ByteBuffer::wrap(m_buffer.offset_pointer(table_offset), table_length); dbg() << "Font file too small";
return nullptr;
}
auto buffer_here = ByteBuffer::wrap(buffer.offset_pointer(table_offset), table_length);
// Get the table offsets we need. // Get the table offsets we need.
if (tag == tag_from_str("head")) { if (tag == tag_from_str("head")) {
head_slice = buffer; opt_head_slice = buffer_here;
} else if (tag == tag_from_str("hhea")) { } else if (tag == tag_from_str("hhea")) {
hhea_slice = buffer; opt_hhea_slice = buffer_here;
} else if (tag == tag_from_str("maxp")) { } else if (tag == tag_from_str("maxp")) {
maxp_slice = buffer; opt_maxp_slice = buffer_here;
} else if (tag == tag_from_str("hmtx")) { } else if (tag == tag_from_str("hmtx")) {
hmtx_slice = buffer; opt_hmtx_slice = buffer_here;
} else if (tag == tag_from_str("cmap")) { } else if (tag == tag_from_str("cmap")) {
cmap_slice = buffer; opt_cmap_slice = buffer_here;
} else if (tag == tag_from_str("loca")) { } else if (tag == tag_from_str("loca")) {
loca_slice = buffer; opt_loca_slice = buffer_here;
} else if (tag == tag_from_str("glyf")) { } else if (tag == tag_from_str("glyf")) {
glyf_slice = buffer; opt_glyf_slice = buffer_here;
} }
} }
// Check that we've got everything we need. if (!opt_head_slice.has_value() || !(opt_head = Head::from_slice(opt_head_slice.value())).has_value()) {
ASSERT(head_slice.has_value()); dbg() << "Could not load Head";
ASSERT(hhea_slice.has_value()); return nullptr;
ASSERT(maxp_slice.has_value()); }
ASSERT(hmtx_slice.has_value()); auto head = opt_head.value();
ASSERT(cmap_slice.has_value());
ASSERT(loca_slice.has_value());
ASSERT(glyf_slice.has_value());
// Load the tables. if (!opt_hhea_slice.has_value() || !(opt_hhea = Hhea::from_slice(opt_hhea_slice.value())).has_value()) {
m_head_slice = head_slice.value(); dbg() << "Could not load Hhea";
m_hhea_slice = hhea_slice.value(); return nullptr;
m_maxp_slice = maxp_slice.value(); }
m_hmtx_slice = hmtx_slice.value(); auto hhea = opt_hhea.value();
m_loca_slice = loca_slice.value();
m_glyf_slice = glyf_slice.value();
m_cmap = Cmap(cmap_slice.value()); if (!opt_maxp_slice.has_value() || !(opt_maxp = Maxp::from_slice(opt_maxp_slice.value())).has_value()) {
dbg() << "Could not load Maxp";
return nullptr;
}
auto maxp = opt_maxp.value();
if (!opt_hmtx_slice.has_value() || !(opt_hmtx = Hmtx::from_slice(opt_hmtx_slice.value(), maxp.num_glyphs(), hhea.number_of_h_metrics())).has_value()) {
dbg() << "Could not load Hmtx";
return nullptr;
}
auto hmtx = opt_hmtx.value();
if (!opt_cmap_slice.has_value() || !(opt_cmap = Cmap::from_slice(opt_cmap_slice.value())).has_value()) {
dbg() << "Could not load Cmap";
return nullptr;
}
auto cmap = opt_cmap.value();
if (!opt_loca_slice.has_value() || !(opt_loca = Loca::from_slice(opt_loca_slice.value(), maxp.num_glyphs(), head.index_to_loc_format())).has_value()) {
dbg() << "Could not load Loca";
return nullptr;
}
auto loca = opt_loca.value();
if (!opt_glyf_slice.has_value()) {
dbg() << "Could not load Glyf";
return nullptr;
}
auto glyf = Glyf(opt_glyf_slice.value());
// Select cmap table. FIXME: Do this better. Right now, just looks for platform "Windows" // Select cmap table. FIXME: Do this better. Right now, just looks for platform "Windows"
// and corresponding encoding "Unicode full repertoire", or failing that, "Unicode BMP" // and corresponding encoding "Unicode full repertoire", or failing that, "Unicode BMP"
for (u32 i = 0; i < m_cmap.num_subtables(); i++) { for (u32 i = 0; i < cmap.num_subtables(); i++) {
auto opt_subtable = m_cmap.subtable(i); auto opt_subtable = cmap.subtable(i);
if (!opt_subtable.has_value()) { if (!opt_subtable.has_value()) {
continue; continue;
} }
auto subtable = opt_subtable.value(); auto subtable = opt_subtable.value();
if (subtable.platform_id() == Cmap::Subtable::Platform::Windows) { if (subtable.platform_id() == Cmap::Subtable::Platform::Windows) {
if (subtable.encoding_id() == (u16)Cmap::Subtable::WindowsEncoding::UnicodeFullRepertoire) { if (subtable.encoding_id() == (u16)Cmap::Subtable::WindowsEncoding::UnicodeFullRepertoire) {
m_cmap.set_active_index(i); cmap.set_active_index(i);
break; break;
} }
if (subtable.encoding_id() == (u16)Cmap::Subtable::WindowsEncoding::UnicodeBMP) { if (subtable.encoding_id() == (u16)Cmap::Subtable::WindowsEncoding::UnicodeBMP) {
m_cmap.set_active_index(i); cmap.set_active_index(i);
break; break;
} }
} }
} }
}
return adopt(*new Font(move(buffer), move(head), move(hhea), move(maxp), move(hmtx), move(cmap), move(loca), move(glyf)));
}
ScaledFontMetrics Font::metrics(float x_scale, float y_scale) const ScaledFontMetrics Font::metrics(float x_scale, float y_scale) const
{ {
Hhea hhea(m_hhea_slice); auto ascender = m_hhea.ascender() * y_scale;
auto ascender = hhea.ascender() * y_scale; auto descender = m_hhea.descender() * y_scale;
auto descender = hhea.descender() * y_scale; auto line_gap = m_hhea.line_gap() * y_scale;
auto line_gap = hhea.line_gap() * y_scale; auto advance_width_max = m_hhea.advance_width_max() * x_scale;
auto advance_width_max = hhea.advance_width_max() * x_scale;
return ScaledFontMetrics { return ScaledFontMetrics {
.ascender = (int)roundf(ascender), .ascender = (int)roundf(ascender),
.descender = (int)roundf(descender), .descender = (int)roundf(descender),
@ -295,19 +364,12 @@ ScaledFontMetrics Font::metrics(float x_scale, float y_scale) const
// FIXME: "loca" and "glyf" are not available for CFF fonts. // FIXME: "loca" and "glyf" are not available for CFF fonts.
ScaledGlyphMetrics Font::glyph_metrics(u32 glyph_id, float x_scale, float y_scale) const ScaledGlyphMetrics Font::glyph_metrics(u32 glyph_id, float x_scale, float y_scale) const
{ {
u32 num_glyphs = glyph_count(); if (glyph_id >= glyph_count()) {
u16 number_of_h_metrics = Hhea(m_hhea_slice).number_of_h_metrics();
auto index_to_loc_format = Head(m_head_slice).index_to_loc_format();
Hmtx hmtx(m_hmtx_slice, num_glyphs, number_of_h_metrics);
Loca loca(m_loca_slice, num_glyphs, index_to_loc_format);
Glyf glyf(m_glyf_slice);
if (glyph_id >= num_glyphs) {
glyph_id = 0; glyph_id = 0;
} }
auto horizontal_metrics = hmtx.get_glyph_horizontal_metrics(glyph_id); auto horizontal_metrics = m_hmtx.get_glyph_horizontal_metrics(glyph_id);
auto glyph_offset = loca.get_glyph_offset(glyph_id); auto glyph_offset = m_loca.get_glyph_offset(glyph_id);
auto glyph = glyf.glyph(glyph_offset); auto glyph = m_glyf.glyph(glyph_offset);
int ascender = glyph.ascender(); int ascender = glyph.ascender();
int descender = glyph.descender(); int descender = glyph.descender();
return ScaledGlyphMetrics { return ScaledGlyphMetrics {
@ -321,33 +383,28 @@ ScaledGlyphMetrics Font::glyph_metrics(u32 glyph_id, float x_scale, float y_scal
// FIXME: "loca" and "glyf" are not available for CFF fonts. // FIXME: "loca" and "glyf" are not available for CFF fonts.
RefPtr<Gfx::Bitmap> Font::raster_glyph(u32 glyph_id, float x_scale, float y_scale) const RefPtr<Gfx::Bitmap> Font::raster_glyph(u32 glyph_id, float x_scale, float y_scale) const
{ {
u32 num_glyphs = glyph_count(); if (glyph_id >= glyph_count()) {
auto index_to_loc_format = Head(m_head_slice).index_to_loc_format();
Loca loca(m_loca_slice, num_glyphs, index_to_loc_format);
Glyf glyf(m_glyf_slice);
if (glyph_id >= num_glyphs) {
glyph_id = 0; glyph_id = 0;
} }
auto glyph_offset = loca.get_glyph_offset(glyph_id); auto glyph_offset = m_loca.get_glyph_offset(glyph_id);
auto glyph = glyf.glyph(glyph_offset); auto glyph = m_glyf.glyph(glyph_offset);
return glyph.raster(x_scale, y_scale, [&](u16 glyph_id) { return glyph.raster(x_scale, y_scale, [&](u16 glyph_id) {
if (glyph_id >= num_glyphs) { if (glyph_id >= glyph_count()) {
glyph_id = 0; glyph_id = 0;
} }
auto glyph_offset = loca.get_glyph_offset(glyph_id); auto glyph_offset = m_loca.get_glyph_offset(glyph_id);
return glyf.glyph(glyph_offset); return m_glyf.glyph(glyph_offset);
}); });
} }
u32 Font::glyph_count() const u32 Font::glyph_count() const
{ {
return Maxp(m_maxp_slice).num_glyphs(); return m_maxp.num_glyphs();
} }
u16 Font::units_per_em() const u16 Font::units_per_em() const
{ {
return Head(m_head_slice).units_per_em(); return m_head.units_per_em();
} }
int ScaledFont::width(const StringView& string) const int ScaledFont::width(const StringView& string) const

54
Libraries/LibTTF/Font.h
View file

@ -26,13 +26,15 @@
#pragma once #pragma once
#include "Cmap.h"
#include <AK/ByteBuffer.h> #include <AK/ByteBuffer.h>
#include <AK/Noncopyable.h> #include <AK/Noncopyable.h>
#include <AK/RefCounted.h> #include <AK/RefCounted.h>
#include <AK/StringView.h> #include <AK/StringView.h>
#include <LibGfx/Bitmap.h> #include <LibGfx/Bitmap.h>
#include <LibGfx/Size.h> #include <LibGfx/Size.h>
#include <LibTTF/Cmap.h>
#include <LibTTF/Glyf.h>
#include <LibTTF/Tables.h>
#define POINTS_PER_INCH 72.0f #define POINTS_PER_INCH 72.0f
#define DEFAULT_DPI 96 #define DEFAULT_DPI 96
@ -66,6 +68,13 @@ class Font : public RefCounted<Font> {
public: public:
static RefPtr<Font> load_from_file(const StringView& path, unsigned index = 0); static RefPtr<Font> load_from_file(const StringView& path, unsigned index = 0);
ScaledFontMetrics metrics(float x_scale, float y_scale) const;
ScaledGlyphMetrics glyph_metrics(u32 glyph_id, float x_scale, float y_scale) const;
RefPtr<Gfx::Bitmap> raster_glyph(u32 glyph_id, float x_scale, float y_scale) const;
u32 glyph_count() const;
u16 units_per_em() const;
u32 glyph_id_for_codepoint(u32 codepoint) const { return m_cmap.glyph_id_for_codepoint(codepoint); }
private: private:
enum class Offsets { enum class Offsets {
NumTables = 4, NumTables = 4,
@ -78,26 +87,29 @@ private:
TableRecord = 16, TableRecord = 16,
}; };
Font(ByteBuffer&& buffer, u32 offset); static RefPtr<Font> load_from_offset(ByteBuffer&&, unsigned index = 0);
ScaledFontMetrics metrics(float x_scale, float y_scale) const; Font(ByteBuffer&& buffer, Head&& head, Hhea&& hhea, Maxp&& maxp, Hmtx&& hmtx, Cmap&& cmap, Loca&& loca, Glyf&& glyf)
ScaledGlyphMetrics glyph_metrics(u32 glyph_id, float x_scale, float y_scale) const; : m_buffer(move(buffer))
RefPtr<Gfx::Bitmap> raster_glyph(u32 glyph_id, float x_scale, float y_scale) const; , m_head(move(head))
u32 glyph_count() const; , m_hhea(move(hhea))
u16 units_per_em() const; , m_maxp(move(maxp))
, m_hmtx(move(hmtx))
, m_loca(move(loca))
, m_glyf(move(glyf))
, m_cmap(move(cmap))
{
}
// This owns the font data // This owns the font data
ByteBuffer m_buffer; ByteBuffer m_buffer;
// These are all non-owning slices // These are stateful wrappers around non-owning slices
ByteBuffer m_head_slice; Head m_head;
ByteBuffer m_hhea_slice; Hhea m_hhea;
ByteBuffer m_maxp_slice; Maxp m_maxp;
ByteBuffer m_hmtx_slice; Hmtx m_hmtx;
ByteBuffer m_loca_slice; Loca m_loca;
ByteBuffer m_glyf_slice; Glyf m_glyf;
// These are stateful wrappers around tables
Cmap m_cmap; Cmap m_cmap;
friend ScaledFont;
}; };
class ScaledFont { class ScaledFont {
@ -109,7 +121,7 @@ public:
m_x_scale = (point_width * dpi_x) / (POINTS_PER_INCH * units_per_em); m_x_scale = (point_width * dpi_x) / (POINTS_PER_INCH * units_per_em);
m_y_scale = (point_height * dpi_y) / (POINTS_PER_INCH * units_per_em); m_y_scale = (point_height * dpi_y) / (POINTS_PER_INCH * units_per_em);
} }
u32 glyph_id_for_codepoint(u32 codepoint) const { return m_font->m_cmap.glyph_id_for_codepoint(codepoint); } u32 glyph_id_for_codepoint(u32 codepoint) const { return m_font->glyph_id_for_codepoint(codepoint); }
ScaledFontMetrics metrics() const { return m_font->metrics(m_x_scale, m_y_scale); } ScaledFontMetrics metrics() const { return m_font->metrics(m_x_scale, m_y_scale); }
ScaledGlyphMetrics glyph_metrics(u32 glyph_id) const { return m_font->glyph_metrics(glyph_id, m_x_scale, m_y_scale); } ScaledGlyphMetrics glyph_metrics(u32 glyph_id) const { return m_font->glyph_metrics(glyph_id, m_x_scale, m_y_scale); }
RefPtr<Gfx::Bitmap> raster_glyph(u32 glyph_id) const { return m_font->raster_glyph(glyph_id, m_x_scale, m_y_scale); } RefPtr<Gfx::Bitmap> raster_glyph(u32 glyph_id) const { return m_font->raster_glyph(glyph_id, m_x_scale, m_y_scale); }
@ -120,10 +132,8 @@ public:
private: private:
RefPtr<Font> m_font; RefPtr<Font> m_font;
float m_x_scale; float m_x_scale { 0.0 };
float m_y_scale; float m_y_scale { 0.0 };
friend Font;
}; };
} }

26
Libraries/LibTTF/Glyf.cpp
View file

@ -24,9 +24,9 @@
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/ */
#include "Glyf.h"
#include <LibGfx/FloatPoint.h> #include <LibGfx/FloatPoint.h>
#include <LibGfx/Path.h> #include <LibGfx/Path.h>
#include <LibTTF/Glyf.h>
namespace TTF { namespace TTF {
@ -147,7 +147,8 @@ private:
Gfx::AffineTransform m_affine; Gfx::AffineTransform m_affine;
}; };
Optional<Glyf::Glyph::ComponentIterator::Item> Glyf::Glyph::ComponentIterator::next() { Optional<Glyf::Glyph::ComponentIterator::Item> Glyf::Glyph::ComponentIterator::next()
{
if (!m_has_more) { if (!m_has_more) {
return {}; return {};
} }
@ -318,6 +319,23 @@ void Rasterizer::draw_line(Gfx::FloatPoint p0, Gfx::FloatPoint p1)
} }
} }
Optional<Loca> Loca::from_slice(const ByteBuffer& slice, u32 num_glyphs, IndexToLocFormat index_to_loc_format)
{
switch (index_to_loc_format) {
case IndexToLocFormat::Offset16:
if (slice.size() < num_glyphs * 2) {
return {};
}
break;
case IndexToLocFormat::Offset32:
if (slice.size() < num_glyphs * 4) {
return {};
}
break;
}
return Loca(slice, num_glyphs, index_to_loc_format);
}
u32 Loca::get_glyph_offset(u32 glyph_id) const u32 Loca::get_glyph_offset(u32 glyph_id) const
{ {
ASSERT(glyph_id < m_num_glyphs); ASSERT(glyph_id < m_num_glyphs);
@ -392,9 +410,7 @@ void Glyf::Glyph::raster_inner(Rasterizer& rasterizer, Gfx::AffineTransform& aff
contour_size = current_contour_end - last_contour_end; contour_size = current_contour_end - last_contour_end;
last_contour_end = current_contour_end; last_contour_end = current_contour_end;
auto opt_item = point_iterator.next(); auto opt_item = point_iterator.next();
if (!opt_item.has_value()) { ASSERT(opt_item.has_value());
ASSERT_NOT_REACHED();
}
contour_start = opt_item.value().point; contour_start = opt_item.value().point;
path.move_to(contour_start.value()); path.move_to(contour_start.value());
contour_size--; contour_size--;

26
Libraries/LibTTF/Glyf.h
View file

@ -26,11 +26,11 @@
#pragma once #pragma once
#include "Tables.h"
#include <AK/ByteBuffer.h> #include <AK/ByteBuffer.h>
#include <AK/FixedArray.h> #include <AK/FixedArray.h>
#include <LibGfx/AffineTransform.h> #include <LibGfx/AffineTransform.h>
#include <LibGfx/Bitmap.h> #include <LibGfx/Bitmap.h>
#include <LibTTF/Tables.h>
#include <math.h> #include <math.h>
namespace TTF { namespace TTF {
@ -50,25 +50,19 @@ private:
class Loca { class Loca {
public: public:
static Optional<Loca> from_slice(const ByteBuffer&, u32 num_glyphs, IndexToLocFormat);
u32 get_glyph_offset(u32 glyph_id) const;
private:
Loca(const ByteBuffer& slice, u32 num_glyphs, IndexToLocFormat index_to_loc_format) Loca(const ByteBuffer& slice, u32 num_glyphs, IndexToLocFormat index_to_loc_format)
: m_slice(slice) : m_slice(slice)
, m_num_glyphs(num_glyphs) , m_num_glyphs(num_glyphs)
, m_index_to_loc_format(index_to_loc_format) , m_index_to_loc_format(index_to_loc_format)
{ {
switch (m_index_to_loc_format) {
case IndexToLocFormat::Offset16:
ASSERT(m_slice.size() >= m_num_glyphs * 2);
break;
case IndexToLocFormat::Offset32:
ASSERT(m_slice.size() >= m_num_glyphs * 4);
break;
} }
}
u32 get_glyph_offset(u32 glyph_id) const;
private:
ByteBuffer m_slice; ByteBuffer m_slice;
u32 m_num_glyphs; u32 m_num_glyphs { 0 };
IndexToLocFormat m_index_to_loc_format; IndexToLocFormat m_index_to_loc_format;
}; };
@ -151,10 +145,10 @@ public:
} }
Type m_type { Type::Composite }; Type m_type { Type::Composite };
i16 m_xmin; i16 m_xmin { 0 };
i16 m_ymin; i16 m_ymin { 0 };
i16 m_xmax; i16 m_xmax { 0 };
i16 m_ymax; i16 m_ymax { 0 };
i16 m_num_contours { -1 }; i16 m_num_contours { -1 };
ByteBuffer m_slice; ByteBuffer m_slice;
}; };

52
Libraries/LibTTF/Tables.h
View file

@ -37,11 +37,7 @@ enum class IndexToLocFormat {
class Head { class Head {
public: public:
Head(const ByteBuffer& slice) static Optional<Head> from_slice(const ByteBuffer&);
: m_slice(slice)
{
ASSERT(m_slice.size() >= (size_t) Sizes::Table);
}
u16 units_per_em() const; u16 units_per_em() const;
i16 xmin() const; i16 xmin() const;
i16 ymin() const; i16 ymin() const;
@ -64,16 +60,17 @@ private:
Table = 54, Table = 54,
}; };
Head(const ByteBuffer& slice)
: m_slice(slice)
{
}
ByteBuffer m_slice; ByteBuffer m_slice;
}; };
class Hhea { class Hhea {
public: public:
Hhea(const ByteBuffer& slice) static Optional<Hhea> from_slice(const ByteBuffer&);
: m_slice(slice)
{
ASSERT(m_slice.size() >= (size_t) Sizes::Table);
}
i16 ascender() const; i16 ascender() const;
i16 descender() const; i16 descender() const;
i16 line_gap() const; i16 line_gap() const;
@ -92,16 +89,17 @@ private:
Table = 36, Table = 36,
}; };
Hhea(const ByteBuffer& slice)
: m_slice(slice)
{
}
ByteBuffer m_slice; ByteBuffer m_slice;
}; };
class Maxp { class Maxp {
public: public:
Maxp(const ByteBuffer& slice) static Optional<Maxp> from_slice(const ByteBuffer&);
: m_slice(slice)
{
ASSERT(m_slice.size() >= (size_t) Sizes::TableV0p5);
}
u16 num_glyphs() const; u16 num_glyphs() const;
private: private:
@ -112,6 +110,11 @@ private:
TableV0p5 = 6, TableV0p5 = 6,
}; };
Maxp(const ByteBuffer& slice)
: m_slice(slice)
{
}
ByteBuffer m_slice; ByteBuffer m_slice;
}; };
@ -122,13 +125,7 @@ struct GlyphHorizontalMetrics {
class Hmtx { class Hmtx {
public: public:
Hmtx(const ByteBuffer& slice, u32 num_glyphs, u32 number_of_h_metrics) static Optional<Hmtx> from_slice(const ByteBuffer&, u32 num_glyphs, u32 number_of_h_metrics);
: m_slice(slice)
, m_num_glyphs(num_glyphs)
, m_number_of_h_metrics(number_of_h_metrics)
{
ASSERT(m_slice.size() >= number_of_h_metrics * (u32) Sizes::LongHorMetric + (num_glyphs - number_of_h_metrics) * (u32) Sizes::LeftSideBearing);
}
GlyphHorizontalMetrics get_glyph_horizontal_metrics(u32 glyph_id) const; GlyphHorizontalMetrics get_glyph_horizontal_metrics(u32 glyph_id) const;
private: private:
@ -137,9 +134,16 @@ private:
LeftSideBearing = 2 LeftSideBearing = 2
}; };
Hmtx(const ByteBuffer& slice, u32 num_glyphs, u32 number_of_h_metrics)
: m_slice(slice)
, m_num_glyphs(num_glyphs)
, m_number_of_h_metrics(number_of_h_metrics)
{
}
ByteBuffer m_slice; ByteBuffer m_slice;
u32 m_num_glyphs; u32 m_num_glyphs { 0 };
u32 m_number_of_h_metrics; u32 m_number_of_h_metrics { 0 };
}; };
} }