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serenity/Userland/Libraries/LibPDF/Fonts/CFF.cpp
Nico Weber bd74447dba LibPDF: Initial support for drawing CFF-based Type0 fonts 
Together with the already-merged #23122, #23128, #23135, #23136, #23162,
and #23167, #23179, #23190, #23194 this adds initial support for
rendering some CFF-based Type0 fonts :^)

There's a long list of things that still need improving after this:

* A small number of CFF programs contain the charstring command 0,
  which is invalid. Currently, this makes us reject the whole font.

* Type1FontProgram::rasterize_glyph() is name-based. For CID-based
  fonts, we want a version that takes CIDs (character IDs) instead.
  For now, I'm printing the CID to a string and using that, yuck.
  (I looked into doing this nicely. I do want to do that, but I
  need to read up on how the `seac` type1 charstring command uses
  character names to identify parts of an accented character.
  Also, it looks like `seac`'s accented character handling moved
  over to `endchar` in type2 charstring commands (i.e. in CFF data),
  and it looks like we don't implement that at all. So I need to do
  more reading first, and I didn't want to block this on that.)

* The name for the first string in name-based CFF fonts looks wrong;
  added a FIXME for that for now.

* This supports the named Identity-H cmap only for now. Identity-H
  maps UTF16-BE values to glyph IDs with the idenity function, and
  assumes it's horizontal text. Other named cmaps in my test files are
  UniJIS-UCS2-H, UniCNS-UCS2-H, Identity-V, UniGB-UCS2-H, UniKS-UCS2-H.
  (There are also 2 files using the stream-based cmaps instead of the
  name-based ones.)

  * In particular, we can't draw vertical text (`-V`) yet

* Passing in the encoding to CFF::create() is awkward (it's nullptr
  for CID-keyed fonts), and it's also not necessary since
  `Type1Font::draw_glyph()` already does the "take encoding from PDF,
  and only from font if the PDF doesn't store one" dance.

* This doesn't cache glyphs but re-rasterizes them each time. Easy
  to add, but maybe I want to look at rotation first. And things
  don't feel glacial as-is.

* Type0Font::draw_glyph() is pretty similar to second half of
  Type1Font::draw_glyph()
2024-02-16 12:41:10 -05:00

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/*
* Copyright (c) 2023, Rodrigo Tobar <rtobarc@gmail.com>.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
// CFF spec: https://adobe-type-tools.github.io/font-tech-notes/pdfs/5176.CFF.pdf
#include <AK/Debug.h>
#include <AK/Endian.h>
#include <AK/String.h>
#include <LibGfx/Forward.h>
#include <LibPDF/Encoding.h>
#include <LibPDF/Error.h>
#include <LibPDF/Fonts/CFF.h>
#include <LibPDF/Reader.h>
namespace PDF {
// The built-in encodings map codes to SIDs.
// CFF spec, "Appendix B Predefined Encodings, Standard Encoding"
// clang-format off
static constexpr Array s_predefined_encoding_standard = to_array<CFF::SID>({
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,
61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89,
90, 91, 92, 93, 94, 95, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 0, 111, 112,
113, 114, 0, 115, 116, 117, 118, 119, 120, 121, 122, 0, 123, 0, 124, 125, 126, 127, 128, 129, 130, 131, 0, 132, 133, 0, 134, 135, 136,
137, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 138, 0, 139, 0, 0, 0, 0, 140, 141, 142, 143, 0,
0, 0, 0, 0, 144, 0, 0,
0, 145, 0, 0, 146, 147, 148,
149, 0, 0, 0, 0,
});
static_assert(s_predefined_encoding_standard.size() == 256);
// clang-format on
// CFF spec, "Appendix B Predefined Encodings, Expert Encoding"
// clang-format off
static constexpr Array s_predefined_encoding_expert = to_array<CFF::SID>({
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 229, 230, 0,
231, 232, 233, 234, 235, 236, 237, 238, 13, 14, 15, 99, 239, 240, 241, 242, 243, 244,
245, 246, 247, 248, 27, 28, 249, 250, 251, 252, 0, 253, 254, 255, 256, 257, 0, 0, 0, 258, 0, 0, 259, 260, 261, 262, 0, 0, 263,
264, 265, 0, 266, 109, 110, 267, 268, 269, 0, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288,
289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 304, 305, 306, 0, 0, 307, 308, 309, 310,
311, 0, 312, 0, 0, 313, 0, 0, 314, 315, 0, 0, 316, 317, 318, 0, 0, 0, 158, 155, 163, 319, 320, 321, 322, 323, 324, 325, 0,
0, 326, 150, 164, 169, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350,
351, 352, 353, 354, 355, 356, 357, 358, 359, 360,
361, 362, 363, 364, 365, 366, 367, 368, 369, 370,
371, 372, 373, 374, 375, 376, 377, 378,
});
static_assert(s_predefined_encoding_expert.size() == 256);
// clang-format on
// Charsets map GIDs to SIDs.
// CFF spec, "Appendix C Predefined Charsets, Expert"
// clang-format off
static constexpr auto s_predefined_charset_expert = to_array<CFF::SID>({
1, 229, 230, 231, 232,
233, 234, 235, 236, 237,
238, 13, 14, 15, 99,
239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 27, 28, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 109, 110,
267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298,
299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 158, 155, 163, 319, 320, 321, 322, 323, 324, 325, 326, 150,
164, 169, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342,
343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 360,
361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378,
});
// clang-format on
// CFF spec, "Appendix C Predefined Charsets, Expert Subset"
// clang-format off
static constexpr auto s_predefined_charset_expert_subset = to_array<CFF::SID>({
1, 231, 232, 235, 236, 237, 238, 13, 14, 15, 99,
239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 27,
28, 249, 250, 251, 253, 254, 255, 256, 257, 258, 259,
260, 261, 262, 263, 264, 265, 266, 109, 110, 267, 268, 269, 270, 272, 300, 301, 302, 305,
314, 315, 158, 155, 163, 320, 321, 322, 323, 324, 325, 326, 150, 164, 169, 327, 328, 329,
330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346,
});
// clang-format on
PDFErrorOr<NonnullRefPtr<CFF>> CFF::create(ReadonlyBytes const& cff_bytes, RefPtr<Encoding> encoding)
{
Reader reader(cff_bytes);
// CFF spec, "6 Header"
// skip major, minor version
reader.consume(2);
auto header_size = TRY(reader.try_read<Card8>());
// skip offset size
reader.consume(1);
reader.move_to(header_size);
// CFF spec, "7 Name INDEX"
Vector<String> font_names;
TRY(parse_index(reader, [&](ReadonlyBytes const& data) -> PDFErrorOr<void> {
auto font_name = TRY(String::from_utf8(data));
dbgln_if(CFF_DEBUG, "CFF font name '{}'", font_name);
return TRY(font_names.try_append(font_name));
}));
if (font_names.size() != 1)
return error("CFFs with more than one font not yet implemented");
auto cff = adopt_ref(*new CFF());
cff->set_font_matrix({ 0.001f, 0.0f, 0.0f, 0.001f, 0.0f, 0.0f });
auto top_dicts = TRY(parse_top_dicts(reader, cff_bytes));
if (top_dicts.size() != 1)
return error("CFFs with more than one font not yet implemented");
auto const& top_dict = top_dicts[0];
if (top_dict.is_cid_keyed) {
// CFF spec, "18 CID-keyed Fonts"
// "* The FDArray operator is expected to be present"
if (top_dict.fdarray_offset == 0)
return error("CID-keyed CFFs must have an FDArray");
// "* The charset data, although in the same format as non-CIDFonts, will represent CIDs rather than SIDs"
// (Done below.)
// "* The Top DICT will include an FDSelect operator"
if (top_dict.fdselect_offset == 0)
return error("CID-keyed CFFs must have FDSelect");
// "* no Encoding operator will be present and the default StandardEncoding should not be applied"
if (top_dict.encoding_offset != 0)
return error("CID-keyed CFFs must not have Encoding");
cff->set_kind(CFF::Kind::CIDKeyed);
}
auto strings = TRY(parse_strings(reader));
// CFF spec "16 Local/Global Subrs INDEXes"
// "Global subrs are stored in an INDEX structure which follows the String INDEX."
Vector<ByteBuffer> global_subroutines;
TRY(parse_index(reader, [&](ReadonlyBytes const& subroutine_bytes) -> PDFErrorOr<void> {
return TRY(global_subroutines.try_append(TRY(ByteBuffer::copy(subroutine_bytes))));
}));
dbgln_if(CFF_DEBUG, "CFF has {} gsubr entries", global_subroutines.size());
// Create glyphs (now that we have the subroutines) and associate missing information to store them and their encoding
auto glyphs = TRY(parse_charstrings(Reader(cff_bytes.slice(top_dict.charstrings_offset)), top_dict.local_subroutines, global_subroutines));
// CFF spec, "Table 16 Encoding ID"
// FIXME: Only read this if the built-in encoding is actually needed? (ie. `if (!encoding)`)
Vector<u8> encoding_codes; // Maps GID to its codepoint.
HashMap<Card8, SID> encoding_supplemental; // Maps codepoint to SID.
if (!top_dict.is_cid_keyed) {
switch (top_dict.encoding_offset) {
case 0:
dbgln_if(CFF_DEBUG, "CFF predefined encoding Standard");
for (size_t i = 1; i < s_predefined_encoding_standard.size(); ++i)
TRY(encoding_supplemental.try_set(i, s_predefined_encoding_standard[i]));
break;
case 1:
dbgln_if(CFF_DEBUG, "CFF predefined encoding Expert");
for (size_t i = 1; i < s_predefined_encoding_expert.size(); ++i)
TRY(encoding_supplemental.try_set(i, s_predefined_encoding_expert[i]));
break;
default:
encoding_codes = TRY(parse_encoding(Reader(cff_bytes.slice(top_dict.encoding_offset)), encoding_supplemental));
break;
}
}
// CFF spec, "Table 22 Charset ID"
Vector<SID> charset; // Maps GID to CIDs for CID-keyed, to SIDs otherwise.
Vector<DeprecatedFlyString> charset_names; // Only valid for non-CID-keyed fonts.
if (top_dict.is_cid_keyed) {
charset = TRY(parse_charset(Reader { cff_bytes.slice(top_dict.charset_offset) }, glyphs.size()));
} else {
switch (top_dict.charset_offset) {
case 0:
dbgln_if(CFF_DEBUG, "CFF predefined charset ISOAdobe");
// CFF spec, "Appendix C Predefined Charsets, ISOAdobe"
for (SID sid = 1; sid <= 228; sid++)
TRY(charset_names.try_append(resolve_sid(sid, strings)));
break;
case 1:
dbgln_if(CFF_DEBUG, "CFF predefined charset Expert");
for (SID sid : s_predefined_charset_expert)
TRY(charset_names.try_append(resolve_sid(sid, strings)));
break;
case 2:
dbgln_if(CFF_DEBUG, "CFF predefined charset Expert Subset");
for (SID sid : s_predefined_charset_expert_subset)
TRY(charset_names.try_append(resolve_sid(sid, strings)));
break;
default: {
charset = TRY(parse_charset(Reader { cff_bytes.slice(top_dict.charset_offset) }, glyphs.size()));
for (SID sid : charset)
TRY(charset_names.try_append(resolve_sid(sid, strings)));
break;
}
}
}
// CFF spec, "18 CID-keyed Fonts"
Vector<TopDict> font_dicts;
if (top_dict.fdarray_offset != 0) {
Reader fdarray_reader { cff_bytes.slice(top_dict.fdarray_offset) };
font_dicts = TRY(parse_top_dicts(fdarray_reader, cff_bytes));
dbgln_if(CFF_DEBUG, "CFF has {} FDArray entries", font_dicts.size());
}
// CFF spec, "19 FDSelect"
Vector<u8> fdselect;
if (top_dict.fdselect_offset != 0) {
fdselect = TRY(parse_fdselect(Reader { cff_bytes.slice(top_dict.fdselect_offset) }, glyphs.size()));
dbgln_if(CFF_DEBUG, "CFF has {} FDSelect entries", fdselect.size());
}
// Adjust glyphs' widths as they are deltas from nominalWidthX
for (size_t glyph_id = 0; glyph_id < glyphs.size(); glyph_id++) {
auto& glyph = glyphs[glyph_id];
if (!glyph.has_width()) {
auto default_width = top_dict.defaultWidthX.value_or(0.0f);
if (top_dict.is_cid_keyed)
default_width = font_dicts[fdselect[glyph_id]].defaultWidthX.value_or(default_width);
glyph.set_width(default_width);
} else {
auto nominal_width = top_dict.nominalWidthX.value_or(0.0f);
if (top_dict.is_cid_keyed)
nominal_width = font_dicts[fdselect[glyph_id]].nominalWidthX.value_or(nominal_width);
glyph.set_width(glyph.width() + nominal_width);
}
}
for (size_t i = 0; i < glyphs.size(); i++) {
if (i == 0) {
if (top_dict.is_cid_keyed) {
// FIXME: Do better than printing the cid to a string.
auto cid = 0;
TRY(cff->add_glyph(ByteString::formatted("{}", cid), move(glyphs[0])));
} else {
// FIXME: Shouldn't this use resolve_sid(0, strings) (".notdef") as name?
TRY(cff->add_glyph(0, move(glyphs[0])));
}
continue;
}
if (top_dict.is_cid_keyed) {
// FIXME: Do better than printing the cid to a string.
auto cid = charset[i - 1];
TRY(cff->add_glyph(ByteString::formatted("{}", cid), move(glyphs[i])));
} else {
auto const& name = charset_names[i - 1];
TRY(cff->add_glyph(name, move(glyphs[i])));
}
}
cff->consolidate_glyphs();
// Encoding given or read
if (encoding) {
dbgln_if(CFF_DEBUG, "CFF using external encoding");
cff->set_encoding(move(encoding));
} else if (!top_dict.is_cid_keyed) {
dbgln_if(CFF_DEBUG, "CFF using embedded encoding");
auto encoding = Encoding::create();
for (size_t i = 0; i < glyphs.size(); i++) {
if (i == 0) {
encoding->set(0, ".notdef");
continue;
}
if (i >= encoding_codes.size() || i >= charset_names.size())
break;
auto code = encoding_codes[i - 1];
auto char_name = charset_names[i - 1];
encoding->set(code, char_name);
}
for (auto const& entry : encoding_supplemental)
encoding->set(entry.key, resolve_sid(entry.value, strings));
cff->set_encoding(move(encoding));
}
return cff;
}
PDFErrorOr<Vector<CFF::TopDict>> CFF::parse_top_dicts(Reader& reader, ReadonlyBytes const& cff_bytes)
{
Vector<TopDict> top_dicts;
TRY(parse_index(reader, [&](ReadonlyBytes const& element_data) -> PDFErrorOr<void> {
TopDict top_dict;
Reader element_reader { element_data };
TRY(parse_dict<TopDictOperator>(element_reader, [&](TopDictOperator op, Vector<DictOperand> const& operands) -> PDFErrorOr<void> {
switch (op) {
case TopDictOperator::Version:
case TopDictOperator::Notice:
case TopDictOperator::FullName:
case TopDictOperator::FamilyName:
case TopDictOperator::Weight:
case TopDictOperator::FontBBox:
case TopDictOperator::UniqueID:
case TopDictOperator::XUID:
case TopDictOperator::Copyright:
case TopDictOperator::IsFixedPitch:
case TopDictOperator::ItalicAngle:
case TopDictOperator::UnderlinePosition:
case TopDictOperator::UnderlineThickness:
case TopDictOperator::PaintType:
case TopDictOperator::FontMatrix:
case TopDictOperator::StrokeWidth:
case TopDictOperator::PostScript:
case TopDictOperator::BaseFontName:
case TopDictOperator::BaseFontBlend:
break;
case TopDictOperator::CharstringType: {
int charstring_type = 2;
if (!operands.is_empty())
charstring_type = operands[0].get<int>();
if (charstring_type != 2)
dbgln("CFF: has unimplemented CharstringType, might not look right");
break;
}
case TopDictOperator::SyntheticBase:
dbgln("CFF: has unimplemented SyntheticBase, might not look right");
break;
case TopDictOperator::Encoding: {
if (!operands.is_empty())
top_dict.encoding_offset = operands[0].get<int>();
break;
}
case TopDictOperator::Charset: {
if (!operands.is_empty())
top_dict.charset_offset = operands[0].get<int>();
break;
}
case TopDictOperator::CharStrings: {
if (!operands.is_empty())
top_dict.charstrings_offset = operands[0].get<int>();
break;
}
case TopDictOperator::Private: {
auto private_dict_size = operands[0].get<int>();
auto private_dict_offset = operands[1].get<int>();
Reader priv_dict_reader { cff_bytes.slice(private_dict_offset, private_dict_size) };
TRY(parse_dict<PrivDictOperator>(priv_dict_reader, [&](PrivDictOperator op, Vector<DictOperand> const& operands) -> PDFErrorOr<void> {
switch (op) {
case PrivDictOperator::BlueValues:
case PrivDictOperator::OtherBlues:
case PrivDictOperator::FamilyBlues:
case PrivDictOperator::FamilyOtherBlues:
case PrivDictOperator::BlueScale:
case PrivDictOperator::BlueShift:
case PrivDictOperator::BlueFuzz:
case PrivDictOperator::StemSnapH:
case PrivDictOperator::StemSnapV:
case PrivDictOperator::ForceBold:
case PrivDictOperator::LanguageGroup:
case PrivDictOperator::ExpansionFactor:
case PrivDictOperator::InitialRandomSeed:
// Ignore hinting-related operators for now.
break;
case PrivDictOperator::StdHW:
case PrivDictOperator::StdVW:
// FIXME: What do these do?
break;
case PrivDictOperator::Subrs: {
// CFF spec, "16 Local/Global Subrs INDEXes"
// "Local subrs are stored in an INDEX structure which is located via the offset operand of the Subrs operator in the Private DICT."
auto subrs_offset = operands[0].get<int>();
Reader subrs_reader { cff_bytes.slice(private_dict_offset + subrs_offset) };
TRY(parse_index(subrs_reader, [&](ReadonlyBytes const& subroutine_bytes) -> PDFErrorOr<void> {
return TRY(top_dict.local_subroutines.try_append(TRY(ByteBuffer::copy(subroutine_bytes))));
}));
dbgln_if(CFF_DEBUG, "CFF has {} subr entries", top_dict.local_subroutines.size());
break;
}
case PrivDictOperator::DefaultWidthX:
if (!operands.is_empty())
top_dict.defaultWidthX = to_number(operands[0]);
break;
case PrivDictOperator::NominalWidthX:
if (!operands.is_empty())
top_dict.nominalWidthX = to_number(operands[0]);
break;
default:
dbgln("CFF: Unhandled private dict entry {}", static_cast<int>(op));
}
return {};
}));
break;
}
case TopDictOperator::RegistryOrderingSupplement:
// CFF Spec, "18 CID-keyed Fonts"
// "The Top DICT begins with ROS operator which specifies the Registry-Ordering-Supplement for the font.
// This will indicate to a CFF parser that special CID processing should be applied to this font."
top_dict.is_cid_keyed = true;
break;
case TopDictOperator::FDSelect:
if (!operands.is_empty())
top_dict.fdselect_offset = operands[0].get<int>();
break;
case TopDictOperator::FDArray:
if (!operands.is_empty())
top_dict.fdarray_offset = operands[0].get<int>();
break;
case TopDictOperator::CIDFontVersion:
case TopDictOperator::CIDFontRevision:
case TopDictOperator::CIDFontType:
case TopDictOperator::CIDCount:
case TopDictOperator::UIDBase:
case TopDictOperator::FontName:
// Keys for CID-keyed fonts that we don't need, at least at the moment.
break;
default:
dbgln("CFF: Unhandled top dict entry {}", static_cast<int>(op));
}
return {};
}));
top_dicts.append((move(top_dict)));
return {};
}));
return top_dicts;
}
/// Appendix A: Standard Strings
static constexpr Array s_cff_builtin_names {
".notdef"sv,
"space"sv,
"exclam"sv,
"quotedbl"sv,
"numbersign"sv,
"dollar"sv,
"percent"sv,
"ampersand"sv,
"quoteright"sv,
"parenleft"sv,
"parenright"sv,
"asterisk"sv,
"plus"sv,
"comma"sv,
"hyphen"sv,
"period"sv,
"slash"sv,
"zero"sv,
"one"sv,
"two"sv,
"three"sv,
"four"sv,
"five"sv,
"six"sv,
"seven"sv,
"eight"sv,
"nine"sv,
"colon"sv,
"semicolon"sv,
"less"sv,
"equal"sv,
"greater"sv,
"question"sv,
"at"sv,
"A"sv,
"B"sv,
"C"sv,
"D"sv,
"E"sv,
"F"sv,
"G"sv,
"H"sv,
"I"sv,
"J"sv,
"K"sv,
"L"sv,
"M"sv,
"N"sv,
"O"sv,
"P"sv,
"Q"sv,
"R"sv,
"S"sv,
"T"sv,
"U"sv,
"V"sv,
"W"sv,
"X"sv,
"Y"sv,
"Z"sv,
"bracketleft"sv,
"backslash"sv,
"bracketright"sv,
"asciicircum"sv,
"underscore"sv,
"quoteleft"sv,
"a"sv,
"b"sv,
"c"sv,
"d"sv,
"e"sv,
"f"sv,
"g"sv,
"h"sv,
"i"sv,
"j"sv,
"k"sv,
"l"sv,
"m"sv,
"n"sv,
"o"sv,
"p"sv,
"q"sv,
"r"sv,
"s"sv,
"t"sv,
"u"sv,
"v"sv,
"w"sv,
"x"sv,
"y"sv,
"z"sv,
"braceleft"sv,
"bar"sv,
"braceright"sv,
"asciitilde"sv,
"exclamdown"sv,
"cent"sv,
"sterling"sv,
"fraction"sv,
"yen"sv,
"florin"sv,
"section"sv,
"currency"sv,
"quotesingle"sv,
"quotedblleft"sv,
"guillemotleft"sv,
"guilsinglleft"sv,
"guilsinglright"sv,
"fi"sv,
"fl"sv,
"endash"sv,
"dagger"sv,
"daggerdbl"sv,
"periodcentered"sv,
"paragraph"sv,
"bullet"sv,
"quotesinglbase"sv,
"quotedblbase"sv,
"quotedblright"sv,
"guillemotright"sv,
"ellipsis"sv,
"perthousand"sv,
"questiondown"sv,
"grave"sv,
"acute"sv,
"circumflex"sv,
"tilde"sv,
"macron"sv,
"breve"sv,
"dotaccent"sv,
"dieresis"sv,
"ring"sv,
"cedilla"sv,
"hungarumlaut"sv,
"ogonek"sv,
"caron"sv,
"emdash"sv,
"AE"sv,
"ordfeminine"sv,
"Lslash"sv,
"Oslash"sv,
"OE"sv,
"ordmasculine"sv,
"ae"sv,
"dotlessi"sv,
"lslash"sv,
"oslash"sv,
"oe"sv,
"germandbls"sv,
"onesuperior"sv,
"logicalnot"sv,
"mu"sv,
"trademark"sv,
"Eth"sv,
"onehalf"sv,
"plusminus"sv,
"Thorn"sv,
"onequarter"sv,
"divide"sv,
"brokenbar"sv,
"degree"sv,
"thorn"sv,
"threequarters"sv,
"twosuperior"sv,
"registered"sv,
"minus"sv,
"eth"sv,
"multiply"sv,
"threesuperior"sv,
"copyright"sv,
"Aacute"sv,
"Acircumflex"sv,
"Adieresis"sv,
"Agrave"sv,
"Aring"sv,
"Atilde"sv,
"Ccedilla"sv,
"Eacute"sv,
"Ecircumflex"sv,
"Edieresis"sv,
"Egrave"sv,
"Iacute"sv,
"Icircumflex"sv,
"Idieresis"sv,
"Igrave"sv,
"Ntilde"sv,
"Oacute"sv,
"Ocircumflex"sv,
"Odieresis"sv,
"Ograve"sv,
"Otilde"sv,
"Scaron"sv,
"Uacute"sv,
"Ucircumflex"sv,
"Udieresis"sv,
"Ugrave"sv,
"Yacute"sv,
"Ydieresis"sv,
"Zcaron"sv,
"aacute"sv,
"acircumflex"sv,
"adieresis"sv,
"agrave"sv,
"aring"sv,
"atilde"sv,
"ccedilla"sv,
"eacute"sv,
"ecircumflex"sv,
"edieresis"sv,
"egrave"sv,
"iacute"sv,
"icircumflex"sv,
"idieresis"sv,
"igrave"sv,
"ntilde"sv,
"oacute"sv,
"ocircumflex"sv,
"odieresis"sv,
"ograve"sv,
"otilde"sv,
"scaron"sv,
"uacute"sv,
"ucircumflex"sv,
"udieresis"sv,
"ugrave"sv,
"yacute"sv,
"ydieresis"sv,
"zcaron"sv,
"exclamsmall"sv,
"Hungarumlautsmall"sv,
"dollaroldstyle"sv,
"dollarsuperior"sv,
"ampersandsmall"sv,
"Acutesmall"sv,
"parenleftsuperior"sv,
"parenrightsuperior"sv,
"twodotenleader"sv,
"onedotenleader"sv,
"zerooldstyle"sv,
"oneoldstyle"sv,
"twooldstyle"sv,
"threeoldstyle"sv,
"fouroldstyle"sv,
"fiveoldstyle"sv,
"sixoldstyle"sv,
"sevenoldstyle"sv,
"eightoldstyle"sv,
"nineoldstyle"sv,
"commasuperior"sv,
"threequartersemdash"sv,
"periodsuperior"sv,
"questionsmall"sv,
"asuperior"sv,
"bsuperior"sv,
"centsuperior"sv,
"dsuperior"sv,
"esuperior"sv,
"isuperior"sv,
"lsuperior"sv,
"msuperior"sv,
"nsuperior"sv,
"osuperior"sv,
"rsuperior"sv,
"ssuperior"sv,
"tsuperior"sv,
"ff"sv,
"ffi"sv,
"ffl"sv,
"parenleftinferior"sv,
"parenrightinferior"sv,
"Circumflexsmall"sv,
"hyphensuperior"sv,
"Gravesmall"sv,
"Asmall"sv,
"Bsmall"sv,
"Csmall"sv,
"Dsmall"sv,
"Esmall"sv,
"Fsmall"sv,
"Gsmall"sv,
"Hsmall"sv,
"Ismall"sv,
"Jsmall"sv,
"Ksmall"sv,
"Lsmall"sv,
"Msmall"sv,
"Nsmall"sv,
"Osmall"sv,
"Psmall"sv,
"Qsmall"sv,
"Rsmall"sv,
"Ssmall"sv,
"Tsmall"sv,
"Usmall"sv,
"Vsmall"sv,
"Wsmall"sv,
"Xsmall"sv,
"Ysmall"sv,
"Zsmall"sv,
"colonmonetary"sv,
"onefitted"sv,
"rupiah"sv,
"Tildesmall"sv,
"exclamdownsmall"sv,
"centoldstyle"sv,
"Lslashsmall"sv,
"Scaronsmall"sv,
"Zcaronsmall"sv,
"Dieresissmall"sv,
"Brevesmall"sv,
"Caronsmall"sv,
"Dotaccentsmall"sv,
"Macronsmall"sv,
"figuredash"sv,
"hypheninferior"sv,
"Ogoneksmall"sv,
"Ringsmall"sv,
"Cedillasmall"sv,
"questiondownsmall"sv,
"oneeighth"sv,
"threeeighths"sv,
"fiveeighths"sv,
"seveneighths"sv,
"onethird"sv,
"twothirds"sv,
"zerosuperior"sv,
"foursuperior"sv,
"fivesuperior"sv,
"sixsuperior"sv,
"sevensuperior"sv,
"eightsuperior"sv,
"ninesuperior"sv,
"zeroinferior"sv,
"oneinferior"sv,
"twoinferior"sv,
"threeinferior"sv,
"fourinferior"sv,
"fiveinferior"sv,
"sixinferior"sv,
"seveninferior"sv,
"eightinferior"sv,
"nineinferior"sv,
"centinferior"sv,
"dollarinferior"sv,
"periodinferior"sv,
"commainferior"sv,
"Agravesmall"sv,
"Aacutesmall"sv,
"Acircumflexsmall"sv,
"Atildesmall"sv,
"Adieresissmall"sv,
"Aringsmall"sv,
"AEsmall"sv,
"Ccedillasmall"sv,
"Egravesmall"sv,
"Eacutesmall"sv,
"Ecircumflexsmall"sv,
"Edieresissmall"sv,
"Igravesmall"sv,
"Iacutesmall"sv,
"Icircumflexsmall"sv,
"Idieresissmall"sv,
"Ethsmall"sv,
"Ntildesmall"sv,
"Ogravesmall"sv,
"Oacutesmall"sv,
"Ocircumflexsmall"sv,
"Otildesmall"sv,
"Odieresissmall"sv,
"OEsmall"sv,
"Oslashsmall"sv,
"Ugravesmall"sv,
"Uacutesmall"sv,
"Ucircumflexsmall"sv,
"Udieresissmall"sv,
"Yacutesmall"sv,
"Thornsmall"sv,
"Ydieresissmall"sv,
"001.000"sv,
"001.001"sv,
"001.002"sv,
"001.003"sv,
"Black"sv,
"Bold"sv,
"Book"sv,
"Light"sv,
"Medium"sv,
"Regular"sv,
"Roman"sv,
"Semibold"sv,
};
PDFErrorOr<Vector<StringView>> CFF::parse_strings(Reader& reader)
{
// CFF spec "10 String Index"
Vector<StringView> strings;
TRY(parse_index(reader, [&](ReadonlyBytes const& string) -> PDFErrorOr<void> {
return TRY(strings.try_append(string));
}));
dbgln_if(CFF_DEBUG, "CFF has {} additional strings in string table", strings.size());
return strings;
}
DeprecatedFlyString CFF::resolve_sid(SID sid, Vector<StringView> const& strings)
{
if (sid < s_cff_builtin_names.size())
return DeprecatedFlyString(s_cff_builtin_names[sid]);
if (sid - s_cff_builtin_names.size() < strings.size())
return DeprecatedFlyString(strings[sid - s_cff_builtin_names.size()]);
dbgln("Couldn't find string for SID {}, going with space", sid);
return DeprecatedFlyString("space");
}
PDFErrorOr<Vector<CFF::SID>> CFF::parse_charset(Reader&& reader, size_t glyph_count)
{
// CFF spec, "13 Charsets"
// Maps `GID - 1` to a SID (or CID, for CID-keyed fonts). The name of GID 0 is implicitly ".notdef".
Vector<SID> names;
auto format = TRY(reader.try_read<Card8>());
if (format == 0) {
// CFF spec, "Table 17 Format 0"
dbgln_if(CFF_DEBUG, "CFF charset format 0");
for (size_t i = 0; i < glyph_count - 1; i++) {
SID sid = TRY(reader.try_read<BigEndian<SID>>());
TRY(names.try_append(sid));
}
} else if (format == 1) {
// CFF spec, "Table 18 Format 1"
dbgln_if(CFF_DEBUG, "CFF charset format 1");
while (names.size() < glyph_count - 1) {
// CFF spec, "Table 19 Range1 Format (Charset)"
auto first_sid = TRY(reader.try_read<BigEndian<SID>>());
int left = TRY(reader.try_read<Card8>());
for (SID sid = first_sid; left >= 0; left--, sid++)
TRY(names.try_append(sid));
}
} else if (format == 2) {
// CFF spec, "Table 20 Format 2"
// "Format 2 differs from format 1 only in the size of the Left field in each range."
dbgln_if(CFF_DEBUG, "CFF charset format 2");
while (names.size() < glyph_count - 1) {
// CFF spec, "Table 21 Range2 Format"
auto first_sid = TRY(reader.try_read<BigEndian<SID>>());
int left = TRY(reader.try_read<BigEndian<Card16>>());
for (SID sid = first_sid; left >= 0; left--, sid++)
TRY(names.try_append(sid));
}
} else {
dbgln("CFF: Unknown charset format {}", format);
}
return names;
}
PDFErrorOr<Vector<u8>> CFF::parse_fdselect(Reader&& reader, size_t glyph_count)
{
Vector<u8> fd_selector_array; // Maps GIDs to their FD index.
// CFF spec, "19 FDSelect"
auto format = TRY(reader.try_read<Card8>());
if (format == 0) {
// CFF spec, "Table 27 Format 0"
// "(This format is identical to charset format 0 except that the notdef glyph is included in this case.)"
dbgln_if(CFF_DEBUG, "CFF fdselect format 0");
fd_selector_array.ensure_capacity(glyph_count);
for (size_t i = 0; i < glyph_count; i++)
fd_selector_array.append(TRY(reader.try_read<Card8>()));
} else if (format == 3) {
// CFF spec, "Table 28 Format 3"
dbgln_if(CFF_DEBUG, "CFF fdselect format 3");
// The spec presents this as n "Card16 first; Card8 fd;" struct entries followed by a Char16 sentinel value.
// But the code is shorter if we treat it as a Char16 start value followed by n "Card8 fd; Card16 end;" struct entries.
Card16 n_ranges = TRY(reader.try_read<BigEndian<Card16>>());
Card16 begin = TRY(reader.try_read<BigEndian<Card16>>());
// "The first range must have a 'first' GID of 0."
if (begin != 0)
return error("CFF fdselect format 3 first range must have a 'first' GID of 0");
for (Card16 i = 0; i < n_ranges; i++) {
auto fd = TRY(reader.try_read<Card8>());
auto end = TRY(reader.try_read<BigEndian<Card16>>());
for (Card16 j = begin; j < end; j++)
fd_selector_array.append(fd);
begin = end;
}
// "The sentinel GID is set equal to the number of glyphs in the font."
if (begin != glyph_count)
return error("CFF fdselect format 3 last range must end at the number of glyphs in the font");
} else {
dbgln("CFF: Unknown fdselect format {}", format);
}
return fd_selector_array;
}
PDFErrorOr<Vector<CFF::Glyph>> CFF::parse_charstrings(Reader&& reader, Vector<ByteBuffer> const& local_subroutines, Vector<ByteBuffer> const& global_subroutines)
{
// CFF spec, "14 CharStrings INDEX"
Vector<Glyph> glyphs;
TRY(parse_index(reader, [&](ReadonlyBytes const& charstring_data) -> PDFErrorOr<void> {
GlyphParserState state;
auto glyph = TRY(parse_glyph(charstring_data, local_subroutines, global_subroutines, state, true));
return TRY(glyphs.try_append(glyph));
}));
dbgln_if(CFF_DEBUG, "CFF has {} glyphs", glyphs.size());
return glyphs;
}
PDFErrorOr<Vector<u8>> CFF::parse_encoding(Reader&& reader, HashMap<Card8, SID>& supplemental)
{
// CFF spec, "12 Encodings"
Vector<u8> encoding_codes;
auto format_raw = TRY(reader.try_read<Card8>());
auto format = format_raw & 0x7f;
if (format == 0) {
// CFF spec, "Table 11 Format 0"
auto n_codes = TRY(reader.try_read<Card8>());
dbgln_if(CFF_DEBUG, "CFF encoding format 0, {} codes", n_codes);
for (u8 i = 0; i < n_codes; i++) {
TRY(encoding_codes.try_append(TRY(reader.try_read<Card8>())));
}
} else if (format == 1) {
// CFF spec, "Table 12 Format 1"
auto n_ranges = TRY(reader.try_read<Card8>());
dbgln_if(CFF_DEBUG, "CFF encoding format 1, {} ranges", n_ranges);
for (u8 i = 0; i < n_ranges; i++) {
// CFF spec, "Table 13 Range1 Format (Encoding)"
auto first_code = TRY(reader.try_read<Card8>());
int left = TRY(reader.try_read<Card8>());
for (u8 code = first_code; left >= 0; left--, code++)
TRY(encoding_codes.try_append(code));
}
} else
return error(ByteString::formatted("Invalid encoding format: {}", format));
if (format_raw & 0x80) {
// CFF spec, "Table 14 Supplemental Encoding Data"
auto n_sups = TRY(reader.try_read<Card8>());
dbgln_if(CFF_DEBUG, "CFF encoding, {} supplemental entries", n_sups);
for (u8 i = 0; i < n_sups; i++) {
// CFF spec, "Table 15 Supplement Format"
auto code = TRY(reader.try_read<Card8>());
SID name = TRY(reader.try_read<SID>());
TRY(supplemental.try_set(code, name));
}
}
return encoding_codes;
}
template<typename OperatorT>
PDFErrorOr<void> CFF::parse_dict(Reader& reader, DictEntryHandler<OperatorT>&& handler)
{
// CFF spec, "4 DICT data"
Vector<DictOperand> operands;
while (reader.remaining() > 0) {
auto b0 = reader.read<u8>();
// "Operators and operands may be distinguished by inspection of their first byte: 0-21 specify operators"
if (b0 <= 21) {
auto op = TRY(parse_dict_operator<OperatorT>(b0, reader));
TRY(handler(op, operands));
operands.clear();
continue;
}
// An operand
TRY(operands.try_append(TRY(load_dict_operand(b0, reader))));
}
return {};
}
template PDFErrorOr<void> CFF::parse_dict<CFF::TopDictOperator>(Reader&, DictEntryHandler<TopDictOperator>&&);
template PDFErrorOr<void> CFF::parse_dict<CFF::PrivDictOperator>(Reader&, DictEntryHandler<PrivDictOperator>&&);
template<typename OperatorT>
PDFErrorOr<OperatorT> CFF::parse_dict_operator(u8 b0, Reader& reader)
{
// CFF spec, "4 DICT data"
VERIFY(b0 <= 21);
// "Two-byte operators have an initial escape byte of 12."
if (b0 != 12)
return OperatorT { (int)b0 };
auto b1 = TRY(reader.try_read<u8>());
return OperatorT { b0 << 8 | b1 };
}
template PDFErrorOr<CFF::TopDictOperator> CFF::parse_dict_operator(u8, Reader&);
PDFErrorOr<void> CFF::parse_index(Reader& reader, IndexDataHandler&& data_handler)
{
// CFF spec, "5 INDEX Data"
Card16 count = TRY(reader.try_read<BigEndian<Card16>>());
if (count == 0)
return {};
auto offset_size = TRY(reader.try_read<OffSize>());
if (offset_size > 4)
return error("CFF INDEX Data offset_size > 4 not supported");
return parse_index_data(offset_size, count, reader, data_handler);
}
PDFErrorOr<void> CFF::parse_index_data(OffSize offset_size, Card16 count, Reader& reader, IndexDataHandler& handler)
{
// CFF spec, "5 INDEX Data"
u32 last_data_end = 1;
auto read_offset = [&]() -> PDFErrorOr<u32> {
u32 offset = 0;
for (OffSize i = 0; i < offset_size; ++i)
offset = (offset << 8) | TRY(reader.try_read<u8>());
return offset;
};
auto offset_refpoint = reader.offset() + offset_size * (count + 1) - 1;
for (u16 i = 0; i < count; i++) {
reader.save();
reader.move_by(offset_size * i);
u32 data_start = TRY(read_offset());
last_data_end = TRY(read_offset());
auto data_size = last_data_end - data_start;
reader.move_to(offset_refpoint + data_start);
TRY(handler(reader.bytes().slice(reader.offset(), data_size)));
reader.load();
}
reader.move_to(offset_refpoint + last_data_end);
return {};
}
int CFF::load_int_dict_operand(u8 b0, Reader& reader)
{
// CFF spec, "Table 3 Operand Encoding"
if (b0 >= 32 && b0 <= 246) {
return b0 - 139;
}
if (b0 >= 247 && b0 <= 250) {
auto b1 = reader.read<u8>();
return (b0 - 247) * 256 + b1 + 108;
}
if (b0 >= 251 && b0 <= 254) {
auto b1 = reader.read<u8>();
return -(b0 - 251) * 256 - b1 - 108;
}
if (b0 == 28) {
auto b1 = reader.read<u8>();
auto b2 = reader.read<u8>();
return b1 << 8 | b2;
}
if (b0 == 29) {
auto b1 = reader.read<u8>();
auto b2 = reader.read<u8>();
auto b3 = reader.read<u8>();
auto b4 = reader.read<u8>();
return b1 << 24 | b2 << 16 | b3 << 8 | b4;
}
VERIFY_NOT_REACHED();
}
float CFF::load_float_dict_operand(Reader& reader)
{
// CFF spec, "Table 5 Nibble Definitions"
StringBuilder sb;
auto add_nibble = [&](char nibble) {
if (nibble < 0xa)
sb.append('0' + nibble);
else if (nibble == 0xa)
sb.append('.');
else if (nibble == 0xb)
sb.append('E');
else if (nibble == 0xc)
sb.append("E-"sv);
else if (nibble == 0xe)
sb.append('-');
};
while (true) {
auto byte = reader.read<u8>();
char nibble1 = (byte & 0xf0) >> 4;
char nibble2 = byte & 0x0f;
if (nibble1 == 0xf)
break;
add_nibble(nibble1);
if (nibble2 == 0xf)
break;
add_nibble(nibble2);
}
auto result = AK::StringUtils::convert_to_floating_point<float>(sb.string_view());
return result.release_value();
}
PDFErrorOr<CFF::DictOperand> CFF::load_dict_operand(u8 b0, Reader& reader)
{
// CFF spec, "4 DICT data"
if (b0 == 30)
return load_float_dict_operand(reader);
if (b0 >= 28)
return load_int_dict_operand(b0, reader);
return Error { Error::Type::MalformedPDF, ByteString::formatted("Unknown CFF dict element prefix: {}", b0) };
}
}
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